Sam Brown Editor

Getting the Most Out of Your Abrasive Tools 13th ed 1939 Forty pages packed with details about using the belt sander, the disk sander, the grinder, the buffing head, with many other details -- over 220 photographs and line-drawings -- organized in 12 chapters and an appendix. Grinding twist drills, using cuttoff-wheels, and just sharpening tools makes this manual almost as useful today as in 1939. I admit that I'm puzzled about the “13th edition”. My inclination is to think of “13 th edition” as 13th printing. By edition, publishers usually mean “editorial changes and revisions”. Instead, I think Delta simply means that this is the 13 th “printing”. Regardless, whether as the 13th edition or 13th reprinting, this number is indicative of how popular this manual on abrasive tools turned out to be. Finally, please forgive me for the lack of uniformity in the document's pages. Very thoughtfully, a website reader pointed out the document's discrepancy: it had several missing pages. Since I was occupied with another area of woodworking history at the time, I simply did a “quick-and-dirty” fix; that is, I scanned in the missing pages, but did not worry about variations in coloriation.

Book No. No. 4531 4531

250

fr

OUTING CE1TINC THE MOST MOST OUT OF OF YOUR YOUR

ABRASIVE ABRASIVE TOOLS TOOLS

ELT

• • • •

THE BELT SANDER THE DISK SANDER THE GRINDER THE BUFFING HEAD

MIL A EE

Published by by Published

DELTIV DELTA/

GETTING THE MOST OUT OF YOUR ABRASIVE TOOLS THIRTEENTH THIRTEENTH EDITION EDITION

A DELTA-CRAFT PUBLICATION PUBLICATION

Edited by SAM BROWN BROWN

A A Complete Complete Manual ManualCovering Covering the the Use Use ofof Abrasive Abrasive Tools in in the the Home Home Workshop, Workshop,Illustrated Illustrated with with Over Photographs and Line Drawings. Over Two TwoHundred Hundred Photographs and Line Drawings.

DELTA POWER TOOL DIVISION DIVISION COMPANY ROCICM CI IMANUFACTURING MANUFACTURING COMPANY

MILWAUKEE 1, WISCONSIN WISCONSIN

Printed in U. U. S. S. A. A.

Form AB-9395-9-50 AB-9395-9-50

Copyright The Delta Manufacturing Manufacturing Co., Co., 1939 1939

CONTENTS MAIN CONTENTS GETTING THE MOST MOST OUT OUT OF OF YOUR ABRASIVE TOOLS CHAPTER CHAPTERONE-ABRASIVE ONE-ABRASIVETOOLS TOOLS The The Grinder—The Grinder—The Buffing Buffing Head—The Head—The Belt Belt Sander—The Sander—The DiskDisk Sander—Sanding Sander—Sanding and and Grinding GrindingAttachments—Mounting Attachments—Mounting Sanding Sanding Disks—Fitting Disks—Fitting Abrasive Abrasive Sleeves—Sane Sleeves—Sane ing Grinding Wheels ing Belts—Mounting Belts—Mounting Grinding Wheels

4-6 4-6

CHAPTER TWO-ABRASIVES TWO-ABRASIVES CHAPTER Natural NaturalAbrasives—Artificial Abrasives—Artificial Abrasives—Grain Abrasives—Grain Size—Grinding Size—Grinding Wheels—Coated Wheels—Coated Abra• Abra• sives—GrindingWheel Wheel Selection—Special Types sives—Grinding Selection—Special Types of of Abrasives Abrasives

7-8

CHAPTER CHAPTERTHREE-OPERATING THREE-OPERATING THE THE BELT BELT SANDER SANDER Surfacing—EndWork—Sanding Work—Sanding Inside Curves—Short Work—Use of Sanding Table— Surfacing—End Inside Curves—Short Work—Use of Sanding Table— Inside Corners—Circle Corners—CircleJigs—Tilting Jigs—Tilting Fence—Pivoted Arm—Beveling Jig—Use of Forms Inside Fence—Pivoted Arm—Beveling Jig—Use of Forms

9-12

CHAPTER CHAPTERFOUR-OPERATING FOUR-OPERATING THE THE DISK DISK SANDER SANDER Freehand Sanding—Pivot Sanding—PivotJigs—Rounding Jigs—Rounding Corners—Pointing Dowels—Use of Miter Freehand Corners—Pointing Dowels—Use of Miter Gage—Grinding Gage—GrindingMetal—Large Metal—Large Work—Sanding Work—Sanding with with Pattern—Sanding Pattern—Sanding to Width—Use to Width—Use of of Double Double Disk—Sanding Disk—SandingLong LongEdges—Selection Edges—SelectionofofAbrasive Abrasive

13-15 13-15

CHAPTER CHAPTER FIVE-GENERAL FIVE-GENERALGRINDING GRINDING

16 16

Safety ofof Tool Rest—Use of of Guides Safety Suggestions—Odd Suggestions—OddJobs—Position Jobs—Position Tool Rest—Use Guides

CHAPTER SHARPEN TOOLS CHAPTERSIX-HOW SIX-HOWTO TO SHARPEN TOOLS General—Wood General—WoodChisels—Honing—Plane Chisels—Honing—Plane Irons—Wood Irons—Wood Turning Turning Tools—The Tools—The Skew Skew Chisel Chisel —The —The Parting PartingTool—The Tool—TheGouge—Lathe Gouge—LatheTo& To& Bits—Circular Bits—Circular Saws—Mortising Saws—Mortising Chisels Chisels —Grinding Jointer Knives—Setting Jointer Knives—Grinding Knives in Head —Grinding Jointer Knives—Setting Jointer Knives—Grinding Knives in Head

17-22 17-22

CHAPTER CHAPTERSEVEN-GRINDING SEVEN-GRINDING SHAPER SHAPER CUTTERS CUTTERS Rake Rake Angle—Amount Angle—Amountofof Bevel—Projected Bevel—Projected Shape—Making Shape—Making a Knife—Use a Knife—Use of Shaped of Shaped Wheels—Honing Wheels—HoningKnives Knives

23-24

CHAPTER TWIST DRILLS CHAPTER EIGHT-GRINDING EIGHT-GRINDING TWIST DRILLS Point Grinding—Web Thinning—Drill for Brass—Special Point Angle—Lip Angle—LipClearance—Drill Clearance—Drill Grinding—Web Thinning—Drill for Brass—Special Grinding—Wheels for forDrill DrillGrinding Grinding Grinding—Wheels

25-27

CHAPTER CHAPTER NINE-BUFFING NINE-BUFFINGAND ANDPOLISHING POLISHING Polishing—Polishing Polishing—PolishingWheels—Setting Wheels—SettingUp—Concerning Up—ConcerningGlue—How Glue—How toto Polish—Buffing Polish—Buffing —Strapping Belts—Buffing Compounds —Strapping Belts—Buffing Compounds

28-30

CHAPTER CHAPTERTEN-HOW TEN-HOWTO TOUSE USESANDING SANDING DRUMS DRUMS Sanding Drums—Sanding onon Drill PressSanding Drums—Sanding Drums—Sandingon onLathe—Narrow-Face Lathe—Narrow-Face Drums—Sanding Drill Press— Pattern Sanding Pattern Sanding

31-32

CHAPTER TO USE CUT-OFF WHEELS CHAPTERELEVEN-HOW ELEVEN-HOW TO USE CUT-OFF WHEELS General General Use—Cutting Use—CuttingTubing—Cutting Tubing—Cutting Solid Solid Stock—Cutting-off Stock—Cutting-off on Grinder—Diamond on Grinder—Diamond Blades—Cutting-off Blades—Cutting-off onon Lathe Lathe

33-34

CHAPTER CHAPTERTWELVE-MISCELLANEOUS TWELVE-MISCELLANEOUS ABRADING ABRADING OPERATIONS OPERATIONS Tumbling—Spun Glass—Engine Finish —— Internal Grinding — Other Tumbling—SpunFinish—Grinding Finish—Grinding Glass—Engine Finish Internal Grinding — Other Lathe Keyways—Surface Grinding—Grinding on Shaper—SandLathe Operations—Grinding Operations—Grinding Keyways—Surface Grinding—Grinding on Shaper—Sanding on Band Saw—Sanding on Lathe ing on Band Saw—Sanding on Lathe

35-38

APPENDIX APPENDIX Abrasives Abrasive Selection—Comparative Grain SizesSizes Abrasives and andAbrasive AbrasiveTerms—Coated Terms—Coated Abrasive Selection—Comparative Grain —Grinding WheelSelection—Wheel Selection—Wheel Speeds—Belt and Drum Speeds—Grinding Wheel —Grinding Wheel Speeds—Belt and Drum Speeds—Grinding Wheel Speeds Speeds in in R. P. M. M.

OTHER OTHER BOOKS BOOKS IN THIS SERIES: • • • • •

39-40

Each Each .250 .250 Postpaid Postpaid

GETTINGTHE THEMOST MOSTOUT OUTOF OF YOUR LATHE GETTING YOUR LATHE GETTING GETTINGTHE THEMOST MOST OUT OUT OFOF YOUR YOUR SHAPER SHAPER GETTING GETTINGTHE THEMOST MOSTOUT OUT OF OF YOUR YOUR DRILL DRILL PRESS PRESS GETTING GETTINGTHE THEMOST MOSTOUT OUT OF OF YOUR YOUR CIRCULAR CIRCULAR SAW SAW AND AND JOINTER JOINTER GETTING BAND SAW AND SCROLL SAW GETTINGTHE THEMOST MOSTOUT OUTOF OFYOUR YOUR BAND SAW AND SCROLL SAW [2] [2]

• ABRASIVE ABRASIVETOOLS TOOLSplay playan animportant importantrole rolein inindustry industryand andin inthe the homeshop. Machines specifically specifically designed designed for for abrading abrading include include the grinder, the belt sander, the disk sander and the buffing head, but practically every other tool in in the the shop shop can can be be set set up up for for abrasive work. Typical operations which are are done done on on one one or or more more of of these machines include sharpening tools, sanding wood and metal, polishing metals and plastics, gumming circular saws, drilling holes in glass, cutting metals and so on through a long list of everyday shop operations. operations. A A working working knowledge knowledge of of abrasives and abrasive methods is essential for for the the successful successful practice practice of of such such work, work,and andititisis the aim of this book to supply this information in a simple, non-technical style readily applied applied to to average average equipment equipment in in the the small smallshop. shop.

ABRASIVE TOOLS These photos show three typical abrasive tools—The Bench Grinder, the Belt Sander, Sander, and and the the Disk Disk Sander. Sander. The grinder is a light-duty model model and and is is belt-driven. belt-driven. The belt sander is a medium-size unit using six inch wide abrasive belts. The disk sander is direct-motor drive and uses twelve inch diameter diameter abrasive abrasive disks. disks. All units are commonly described according to the six inch inch grinder (wheel diameter), a abrasive abrasive area—a area—a six sander (belt (belt width), width), aa twelve twelveinch inchdisk six six inch inch belt sander sander (disk diameter). diameter).

W1-4 EEL WHEEL 7:/ARD _ •GUARD

PULLEY GUARD GUARD

4111ftimig,

ABRASIVE ABRASIVE BELT

TRACKING ADJUSTMENT

BELT TENSIONER

TILTING TABLE

_TILT _T ILT SCALE

PULLEY

& & BELT BELT

SPINDLE

GUARD

DUST DEFLECTOR

LIGHT-DUTY BENCH GRINDER

BELT SANDER SANDER

G U ND ND 1/2 H,P, MOTOR

•1

1

ABRASIVE DISK CEMENTED TO TO PLATE PLATE

T1 TI LT LT IN IN G TABLE

TILT AOJUSTME ADJUSTME

MOTOR-DRIVE MOTOR-DRIVE DISK SANDER SANDER GAGE \M IT,MITER ER GAGE

141 141

CHAPTER ONE

ABRASIVE TOOLS Grinderisisaadouble doubleend end The Grinder. Grinder.—The The Grinder horizontal spindle horizontalspindle, spindle,the theends endsofofthe the spindle being being threaded threadedand andfitted fitted with with flanges flanges to to take take the thegrinding grindingwheels. wheels.The The spindle spindle is is of ten ten aa continuation continuationof ofthe themotor motor shaft, shaft, in which which case case the theunit unitisisdirect-driven. direct-driven. Othermodels modelsemploy employaaconventional conventional belt Other belt drive. The Thesize sizeof ofthe thegrinder grinder commonly drive. isiscommonly taken ofof the abrasive taken from fromthe thediameter diameter the abrasive wheel used is,is, aa used in in connection connectionwith withit,it,that that grinder grinderswinging swingingaa7-inch 7-inchwheel wheelwould would bebe called aa 7-inch 7-inchgrinder. grinder.Units Units are further called are further describedas asbench benchor orpedestal, pedestal, the latter described the latter indicating indicatingaafloor floormodel. model. An essential essential feature featureof ofall all grinders grindersisisthe thewheel wheelguards. guards. these these should shouldenclose enclosethe thewheel wheel as fully fully as as possible possible in inorder ordertoto prevent preventabrasive abrasivechips chips oror Above, belt-drive belt-drivebench benchgrinder grinderfitted fitted with withsafety safetyhoods hoodsas aswell wellas aswheel wheel the wheel larger largerfragments fragmentsofofthe guards. guards. The The buffing buffinghead, head,left, left, isis from operfrom being beingthrown thrownatatthe the opersimilar except guards similarto toaagrinder grinder except guards be ator. ator.The Thetool toolrests restsshould should and and tool tool rests rests are areomitted. omitted.Lower Lower adjustable for adjustabletotoallow allow forwheel photos show a light-duty light-duty buffing buffing head. head. wear, wear, and andin inprecision precisiongrindgrindLike Like most most similar similarbelt-drive belt-drive units, units, it it ers, tilt. ers, are arealso alsoadjustable adjustablefor for tilt. can be driven driven from fromeither either bottom bottom or or back as desired. back as desired. The The power power required requiredtotooperate operate a 6 or or 7-inch 7-inch grinder grinderisisapproxapproximately imately 1/3 1/3 h. h. p. p. Where Wherethe theunit unitisisdirectdirecttn. r. p.in. driven, 3400 r. p. driven, the themotor motormust mustbebea a 3400 type type in in order orderto togive givethe thegrinding grinding wheel wheel an an efficient efficient rim rimspeed. speed.5500 5500surface surfacefeet feet per per minute minuteisisaafair fairstandard standard forfor average average grinding, grinding,although althoughmuch much higher higher speeds speeds are are sometimes sometimesused usedfor forspecial specialwork. work. buffing head headis is The buffing The Buffing Buffing Head. Head.—The mechanically except mechanicallysimilar similartotothe thegrinder grinder except that that guards guardsand andrests rests are are notnot required. required. A A surface surface speed speedof ofabout about6500 6500f.f.p.p.m. m.isis suitable suitable for foraverage averagework. work. plate of bebe run at at of this this diameter diametershould should run The Belt Belt Sander. Sander.—The The belt belt sander sanderfeatures features A plate about 1725 1725 r. r.p. p.m. m.(standard (standard motor motor speed). speed). a continuous continuousabrasive abrasivebelt belt which which works works over over about This will will give aa surface surfacespeed speedranging rangingfrom from pulleys pulleys at at either eitherend endof ofaamain main sanding sanding This 5500 zero at at the thecenter centerof ofthe thedisk disktotoabout about 5500 table. provided forfor tentable. Adjustments Adjustmentsare are provided ten- zero f.p.m. at at the therim. rim.Materials Materials likely clog likely toto clog sioning belt. The size of of f.p.m. sioning and andtracking trackingthe the belt. The size the abrasive abrasiveshould shouldbe beworked worked more toward more toward the the unit unitis iscommonly commonlydesignated designatedthe the same same the the center centerof of the thedisk. disk. as as the the width widthof ofthe thesanding sandingbelt belt which which it it the uses. One-half horsepower One-halfto tothree-quarter three-quarter horsepower Sanding and Grinding Attachments. Attachments. — Acis required the belt sander. Pulrequiredto tooperate operate the belt sander. Pul- cessories cessories for forsanding sandingor orgrinding grinding are are used used leys should should be be such suchas aswill willgive giveaasurface surface on the the drill drillpress, press,lathe, lathe,scroll scrollsaw saw and other and other speed between between 2800 2800 and and3200 3200feet feetper per machines. speed machines. The Thesanding sandingdrum, drum, used used onon the the minute. minute. lathe lathe or ordrill drillpress, press,isisthe the best best known known and and The Disk Sander. Sander.—The The disk disk sander sandercomcom- most most used. used. The Thesurface surfacespeed speedofofsuch suchdrums drums prises operates in in a a is best prises aa circular circularplate platewhich which operates best held held to to aacomparatively comparativelylow lowfigure. figure. vertical vertical position. position.Cloth Clothor orpaper paper backed backed say 1200 f p. averp. m. m. as as compared comparedwith withan an averabrasive oror otherwise abrasivedisks disksare arecemented cemented otherwise age of about about3000 3000f.f. p. p.m. m.for forlong longbelts. belts.AA fastened fastened to to the theplate. plate.The Thediameter diameter ofof the the simple simple test test for forefficient efficientspeed speedisisindicated indicated abrasive abrasivedisk diskindicates indicatesthe thesize sizeofofthe the mama- by the will glaze the abrasive abrasivedrum drumitself, itself,which which will glaze chine, aa common commonsize sizebeing beingtwelve twelveinches. inches. quickly chine, a speed. quickly when when operated operatedatattoo toohigh high a speed. —

—

—

—

—

[5 1 [51

ABRASIVE SLEEVE SLEEVE

,..„___.,c0 Ro,,47.

RUBBER

DIST IC INTERLOCK

SPINDLE SPINDLE NUT

PATCN1 PATCF1 1

CUTAWAY CUTAWAY VIEW VIEW OF OF SANDING SANDINGDRUM DRUM STICK

§.1.122

.

GRINDING GRINDING WHEEL WNEEL

•

BLOTTER BLOTTER

BIOME SKIVE FLANGE FLANGE BELT SPLICES

1

SPINDLE SPINDLE

k LEAD /—

The proper mounting of the abrasive abrasive wheel, wheel, disk or belt is important. Disks must be be adadhered hered flatly flatly and and smoothly in order to do do

BUSHING

CUP CUP WASHER WASHER

0 0

good work; work; belt belt splices must must be becarefully carefully made in order order to to secure securepliability, pliability, strength, strength, made in

0

and a a non-bump non-bump surface. surface.

Mounting Sanding Sanding Disks.—In Disks.—In order to prepresent a true, flat abrasive surface surface to to the the work, sanding disks are mounted on an accurately-machined metal plate. Glue can be used as the adhesive, in which which case case the the plate and disk must be clamped between boards and allowed to dry overnight. overnight. SpeSpecial types of adhesive are also used, used, one one of the most common being "Distic." Distic Distic is a stick shellac which melts melts under under heat heat and then quickly hardens. To To apply apply Distic, Distic, a softwood stick is placed flat flat against against the the bare revolving disk and held held firmly firmly in in place place for about half-a-minute in order to heat the plate. The stick shellac is then then held held against against the revolving disk, as in in Fig. Fig. 1, 1, and and is is moved over the surface until a thin thin even even coat is applied. The abrasive disk is is then then pressed into position, as shown in Fig. Fig. 2. 2. Fitting Abrasive Abrasive Sleeves. Sleeves.—Abrasive Abrasive sleeves are mounted on special drums in which alternate layers of rubber and fiber, fiber, as as shown in Fig. 3, can be be expanded expanded by by turnturning the spindle nut, thus securing the sleeve in place. place. Sanding Belts. Sanding Belts.—Sanding Sanding belts can be purchased readymade for most belt sanders. sanders. The worker can also make his own belts by splicing the sandpaper to form a belt of the proper length. length. Several Several varieties varieties of belt splices are in common use. use. The The interlocking splice, Fig. 4, is made with an inexpensive cutter. A A cloth cloth patch patch is is necesnecessary to retain the two ends ends in in position. position. —

—

[ 6 ]]

This splice is very strong and easy to make, make, but has the disadvantage of a bump at the joining point caused by the patch. The plain butt splice, Fig. 5, is made without special cutting equipment, the cut ends of the belt being simply patched together at either 45 or 90-degrees. The The skived skived joint. joint. Fig. 6, is the one most commonly used. If one end only of the belt is skived, the joint is a single skive; skive; if if both both ends ends are are skived. skived the joint is a double skive. Any suitable angle can be used in making the joint. The grain can be skived from the belt ends by using an abrasive stick stick about about three three sizes sizes coarser than the belt. Where a suitable suitable abraabrasive brick is not available, the skive skive can can be be made made by dipping the belt end into hot water, as shown in Fig. 7, 7, after after which which the abrasive and glue can be readily removed removed from the cloth backing. The joint joint is is put put up up with a light coat of medium thick hot glue and is held in a suitable suitable press press until until dry. dry. as in Fig. 9. 9. Mounting Grinding Grinding Wheels. Wheels.—Good Good quality grinding wheels are metal bushed bushed and and should be a snug fit on the the spindle. spindle. Disks Disks of blotting paper should be used on either side of the wheel to serve as as shock shock absorbabsorbers. The washer which holds the wheel in place should be of the cup type—never a flat washer. The spindle nut should should be be turned up securely, and the thread of the spindle must be such that the nut locks locks against the direction of rotation. rotation. —

CHAPTER TWO

ABRASIVES ABRASIVES

Natural Abrasives.—Natural Abrasives.—Natural abrasives abrasives are are 12•GRAIN 12•GRAINSCREEN SCREEN found found ready readymade madeininthe theearth earth and and include include sandstone, sandstone,emery, emery,flint, flint,garnet, garnet, etc. etc. Each Each has has its its own own particular particular use. use. Flint Flint is is the the least least expensive expensive and andisisthe thetype typeofofabrasive abrasive commonly commonly associated associatedwith with"sandpaper." "sandpaper." ♦ I" ® 0 Garnet Garnetisismuch muchharder harder and and tougher tougher than than 000000DOOCIO OBLONG OBLONG POLYHEDRAL POLYHEDRAL TWELVE GRA/MS e'ec2;1519, SHAPE SHAPE SHAPE SHAPE flint used byby the flint and andis isthe theabrasive abrasivemost most used the pockes. poaes.Al* Et* it woodworker. woodworker.Emery Emeryisiscommonly commonlyused used for for 7 .11, Jad loves% loree0,7, • . sanding list ofof sandingmetals. metals.For Fora acomplete complete list ,,... 111.10,.. - 44-40• 440-40.44,,P 440P oisor •• noyit.•47,2.• fee noit.•47,11.a foe VI:4.W %%0' abrasives seesee thethe • . wft.w. abrasivesand andtheir theircharacteristics, characteristics, BOND • • GRAINS "1147C ABRASIVE GRAINS e, table table in in the theappendix. appendix. SECTION TFIRU GRINDING WHEEL WHEEL TNRU GRINDING STRA GAT GRTCUP CUPDISH DISH abrasives STRA Artificial Artificial Abrasives. Abrasives.—Artificial Artificial abrasives GRINDING WHEELS WHEELS are are aa product productofofthe theelectric electric furnace. furnace. The The WHEELS two main oxide main groups groupsare are(1) (1)aluminum aluminum oxide ABRASIVE GRAINS GRAINS ABRASIVE GLUE GLUE abrasives, abrasives,(2) (2)silicon siliconcarbide carbideabrasives. abrasives. CY-1C 6 Aluminum Aluminumoxide oxideisismade madeby byfusing fusingbauxite, bauxite, pk-lL COATINGOF OFPOLYHEDRAL POLYHEDRAL GRAIN GRANC D a highly highly aluminous aluminousclay, clay,in inan anelectric electric arc arc COATING furnaceat atabout about3,000 3,000degrees degrees The furnace F.F. The DISKS AND SHEETS crystals crystals are areusually usuallybrown brown inin color, color, but but .0911ν ZI4 1 k/11 1.0 COATINGOF OFOBLONG OBLONGGRAINS GRAINS some types types are aremade madegray grayand and white. white. They They COATING are silicon carbide but areare are not notas ashard hardasas silicon carbide but much much tougher. tougher.Silicon Siliconcarbide carbide isismade made byby DRUMS DRUMS ,SPLICE ,SPLICE ELECT ROCOATING COATING fusing fusing sand sandand andcoke cokeatata ahigh hightemperature. temperature. ELECTRO The inin hardness The resulting resultingcrystals crystalsare arenext next hardness to the the diamond, diamond,but butare are brittle brittle as as opposed opposed to the the toughness toughnessof ofaluminum aluminum oxide. oxide. The The II BELTS color toto blue-green. color ranges rangesfrom fromblack-gray black-gray blue-green. COATED ABRASIVES Both Both aluminum aluminumoxide oxideand andsilicon silicon carbide carbide Abrasive Abrasivegrains grains are graded passing through screens are graded byby passing through screens are are sold sold under undervarious varioustrade trade names names such such as as and various abrasive products. and are are then thenmade madeinto into various abrasive products. Aloxite, Alundum Alundumand andLionite Lionite(aluminum (aluminum shapes, aa few few of of the themost mostcommon commonstyles styles oxide), and Crystolon andandshapes, and Carborundum, Carborundum, Crystolon being being the the straight, straight,cup cupand and dish dish wheels wheels Carsilon Carsilon(silicon (siliconcarbide). carbide). shown shown in in Fig. Fig. 5. 5. Grain Grain Size. Size.—The The grain grain size size or orgrit gritisisdedeCoated Abrasives. Coated Abrasives. — Abrasive Abrasive grains grains terminedby bypassing passingthe thecrushed crushed ore over glued termined ore over glued to to sheets sheetsof ofcloth clothor orpaper paper are are known known various various wire wireand andsilk silkscreens. screens.Fig. Fig.1 1shows shows as coated coated abrasives. abrasives.Disks Disksand andsheets, sheets, a passed byby this a 12-grain 12-grainscreen. screen.Grains Grains passed this drums, drums,and andbelts beltsare are common common examples examples of of screen screen are arecalled calledNo. No.12, 12,twelve twelvegrains grains coated grain coated abrasives. abrasives.The Thepolyhedral polyhedral grain measuring measuringabout about11inch inchififlaid laid end end toto end. end. shape shape is is always alwaysused usedwhen whencoated coatedabraabraScientific and Scientific control controlmethods methodseliminate eliminateflat flat and are made madeby byordinary ordinary methods, promethods, proslivery for slivery grains, grains,Fig. Fig.2, 2,unless unlessdesired desired for sives are ducing that shown in in ducing aa surface surfacesimilar similartoto that shown some specific purpose, purpose,retaining retainingonly onlythe the Fig. 6. It It can canbe beseen seenthat thatany any method method ofof ideal shown in in gravity ideal polyhedral-shaped polyhedral-shapedgrain grain shown gravity coating coatingwith withoblong oblonggrains grains would would Fig. 3. Sizes range range from fromNo. No.66to toNo. No.240. 240. result surface, many of of result in inan anunsatisfactory unsatisfactory surface, many Since ofof the Since it it is is difficult difficultto tomake makea ascreen screen emthe grains grainsbeing beingalmost almostcompletely completely emmore finer more than than240 240meshes meshesto tothe theinch, inch, finer bedded in inthe theglue gluecoating, coating,asasshown shown inin grains grains up upto toNo. No.600 600are aregraded graded byby anan bedded Fig. 7. If placed onon If the the oblong oblonggrains grainsare are placed elaborate elaboratewater waterflotation flotationsystem. system. end, end,as as in in Fig. Fig. 8, 8, the the result resultis isquite quitedifferdifferGrinding Wheels.—Abrasive Grinding Wheels. being fully exAbrasive grains grains fused fused erent, erent, the theabrasive abrasiveparticles particles being fully exwith subhigh with aa bond bondof offlux fluxand andclay clayororother other sub- posed posed and andcapable capableof ofclean, clean,uniform, uniform, high stance stance can canbe becast castinto intoany anyconvenient convenient speed speed sanding. sanding.This Thisvertical verticalcoating coating ofof shape, shape, such suchas asthe thefamiliar familiargrinding grinding wheel. wheel. abrasive abrasivegrains grainsisisdone doneby byan anelectrostatic electrostatic Each Each grain grainthus thusbecomes becomesa aminiature miniature cutcut- method, method, and andthe thegreater greater portion portion of of allall ting ting tool, tool, as as shown shownin inFig. Fig.4. 4.As Asthe the coated coated abrasives abrasivesused usedtoday todayare are made made in in manner. grains grains wear weardown downand andbecome become dull, dull, they they this manner. are are torn tornloose loosefrom fromthe the bond, bond, exposing exposing a a Coated into many Coated abrasives abrasivesare aredivided divided into many new, sharp sharpset setof ofcutting cuttingedges. edges.Grinding Grinding different the abradifferentclasses, classes,depending dependingupon upon the abrawheels are are made madein inhundreds hundreds ofof different different sive used, forfor used, the the kind kindof ofbacking, backing,whether whether

7

(

—

—

—

—

[[7] 7]

CLASSIFICATION OF GRINDING WHEELS GRAIN SIZES: Number of Abrasive Grains to the Inch. FLOUR SIZES

VERY COARSE

COARSE

MEDIUM

FINE

VERY FINE

8

12

30

70

150

280

10

14

36

80

180

320

16

46

90

220

400

20

60

100

240

500

24

600

120

GRADE: Strength of Bond. VERY SOFT

SOFT

MEDIUM

Carborundum

W, V, U

T, S, R, P, 0, N

M, L, K, J, I

H, G, F

E, D

Norton

E, F, G

H, I, J, K

L, M, N, 0

P, Q, R, S

T, U, W, Z

HARD

VERY HARD

coarse grain gives best results; for hard, brittle materials, the abrasive grains should be fine. The general run of work is done with 60-grit wheels. The grade of a grinding wheel describes the bond as being hard, medium or soft. Grains are easily loosened from a soft wheel, making it practically self-dressing, while the hard wheel holds together under extreme pressure. Hard wheels are generally used for grinding soft materials, while soft wheels are used for grinding hard materials. For all average work, a medium hard grade will wear well while retaining a sharp edge. The selection of the proper structure is determined by the nature of the material to be ground. Generally, soft materials, which tend to clog any abrasive wheel, require a wheel with abrasive grains widely spaced. Opposite to this, hard, brittle materials require a wheel with closelyspaced abrasive grains. The wide spacing gives a coarse finish; the close spacing, fine. Vitrified wheels are the common selection as to bond. Cut-off wheels subject to deflection strains are generally bonded with resin, shellac or rubber.

wet or dry sanding, etc. In any of these, the normal coating is put on in a close, packed formation, hence the general descriptive term "closed coat." The closed coat is fast-cutting and durable, but has the disadvantage of clogging under certain conditions. Where the coating is spaced to show a slight separation between the abrasive grains, the coating is described as "open coat." Open coated abrasives are not as durable as close coated, but they are useful for finishing certain materials where the abrasive dust tends to clog the disk or belt. In a somewhat similar manner, the grains in a grinding wheel are spaced, the word "structure" being generally used to indicate this abrasive spacing. For all average usage, grinding wheels are supplied in a medium structure. Grinding Wheel Selection.—Most grinders are supplied with a general-purpose grinding wheel and this wheel will handle most of the work encountered in the home or small production shop. Where, for any reason, a special wheel is required, the user can arrive at a workable selection by following a few simple rules. Every grinding wheel has five distinguishing features: (1) Abrasive (aluminum oxide, silicon carbide, etc.), (2) Grain (size of abrasive grains), (3) Grade (strength of bond), (4) Structure (grain spacing), (5) Bond (what kind of material used). The abrasive should be considered first. Only the aluminum oxide and silicon carbide abrasives need be considered. Aluminum oxide is used for grinding all materials of high tensile strength, such as carbon steels, high speed steel, malleable iron, wrought iron, etc. Silicon carbide is used for grinding materials of low tensile strength, such as gray iron, brass and soft bronze, aluminum, copper, etc. Either type of abrasive will, generally speaking, give workable results in either class. The grain selection is comparatively simple. For soft, malleable materials, a

I

Special Types of Abrasives.—Both aluminum oxide and silicon carbide abrasives are made to special formula other than standard. The pure white aluminum oxide wheel is not as tough as regular aluminum oxide, and hence fractures under mild pressure. This feature prevents overheating, making white aluminum oxide suitable for grinding high speed steel. The principal variation from regular silicon carbide is the green crystal, which features a low order of toughness but is extremely hard and brittle. This feature makes green silicon carbide ideal for cutting and grinding glass and extremely hard alloys. The hardest of all abrasive grains is the diamond, and this type of grinding wheel, made from genuine diamond chips, is extensively used for cutting and grinding glass, and for cutting shapes from blocks of silicon carbide and aluminum oxide.

[ 8]

CHAPTER

THREE

OPERATING THE BELT SANDER Surfacing.—The sanding table should be in a horizontal position for surfacing. Work can be done freehand, that is, the piece to be surfaced is simply placed on the table. A light but firm pressure should be used to keep the work in the proper position. Excessive pressure against the belt is unnecessary and should be avoided. If the work is longer than the table, it is started at one end and gradually advanced in much the same manner as surfacing on the jointer. Where long work is to be surfaced, it is advisable to use the sanding fence as a guide, especially if the board is close to 6 inches wide. End Work.—End sanding is best done with the sanding table in a vertical position, but can be done on the horizontal table by using a guide clamped to the fence, as shown in the drawing. The work is pushed down alongside the guide until it contacts the

zGOIDE

Above, surfacing long work. Left, use of diagonal feed.

sanding surface. The alignment block permits rapid attachment of the guide at proper right angle position. Diagonal Feed. — The use of a diagonal feed, as shown in the center drawing, permits the Curves are sanded on the surfacing of work conouter drum, left. Photos siderably wider than show use of backstop. the 6-inch capacity of the belt. The angle of the fence should be kept as small as possible in order to minimize cross grain sanding. A fine belt should be used.

Sanding Inside Curves.—Inside curves can be sanded on the end drum, as shown in the lower drawing. The table can be either vertical, horizontal, or at an angle. The fence is used as a guide, being held by one bracket only so it

1 91

secured arm byby secured to tothe theforks forksofofthe thepivoting pivoting arm means form means of of anchor anchorpoints. points.AAmaster master form should should be be used usedto tolocate locatethe thework work atat the the proper drawing shows properposition. position.The Thelower lower drawing shows a the a simple simple jig jig for forsanding sandingcircles circleswhen when the sanding sanding table tableisishorizontal. horizontal. Holes Holes inin the the fence to to take takethe thebolts boltsare arefor for aa slide slide fitfit so that to to obtain that the thenuts nutscan canbe beturned turned obtain adjustments beadjustmentsfor forcircles circlesofofa adiameter diameter between tween the the one-inch one-inchspacings spacingson onthe the guide guide board.Normally, Normally,circle circlework work done with board. is is done with the using the the sander sanderin inaavertical verticalposition, position, using the sanding sanding table tableas asaasupport. support. The The same same jigs jigs as described sander can describedfor foruse useon onthe thedisk disk sander can be used used on on the thebelt beltsander. sander. Extremely Extremely large largecircles circles can can be be worked workedby bymountmounting the the pivot pivotpoint pointon onany any convenient convenient bench benchor or on the the table tableof ofthe the drill drill press. press.

Above, using using the the tilting tiltingtable. table. Photo Photo at at right rightshows showshow howinside inside corners cornersare aresonded. sonded. I

extends extends beyond beyondthe the sanding sanding belt. belt. Short Short Work. Work. — — No feed is required requiredon on short short work workup upto to about about 12 12 inches incheslong, long, since the the full full length length of such such work workis isin in contactwith with positive contact a level surface. surface. This This permits permitsthe theuse useof ofaa backstop backstopto tosimplify simplify sanding sanding operations. operations. The The backstop backstopcan canbe be used used alone alone or orin inconconnection nection with with the thefence, fence,as as shown shown in in the thephotos photosat at the the bottom bottomof ofthe theprecedpreceding page. page. The Thefence fenceitself itselfcan can also be be used used as asaastop stopby byswingswinging it it at at right rightangles anglesacross acrossthe the sanding sanding surface. surface. Use of Sanding Table. — Every Every kind kind of of edge edge or orend endwork workcan can be done done by by using usingthe thebelt beltsandsander er in in aa vertical verticalposition positionininconconnection nection with with the thesanding sandingtable. table. With With the thetable tablelevel leveland andwith with the the work workguided guidedby bythe themiter miter gage, ends ends and andedges edgescan canbe besandsanded true trueand andsmooth, smooth,either either square, square, mitered, mitered,beveled beveledor orcompound compoundbeveled beveled as required. showrequired.AAtypical typicaloperation operation showing use use of of the the miter mitergage gagewith withtilted tilted table table is shown work is is PIN shown in in upper upperphoto. photo.Other Other work done done in in the thesame samemanner manner asas described described in in following chapter chapteron onuse useof ofthe thedisk disksander. sander. HOLES Inside Inside Corners. Corners.— — Inside Inside corners cornerscan canbe be sanded the belt soso that it runs sanded after aftertracking tracking the belt that it runs exactly exactly flush flush with withthe theedge edgeof ofthe themain mainsandsanding table. table. The Theside sideguard guardplate plate must must bebe re-removed moved to to permit permitfeeding feedingthe thework. work. The The work work is advanced miter advancedto tothe thebelt beltalongside alongsidethe the miter GUIDE, gage, as as shown shown in inthe thecenter centerphoto. photo. AA cut cut GUIDE can can be be taken takenon onboth bothedges edgesofofthe thecorner corner in in BOLT one operation, worked operation,or, or,each eachedge edgecan canbebe worked BOLT NUT— NUT— turnon onthe theflat flatsurface surface the belt. in turn ofof the belt. PENCE FENCE Circle Circle Jigs.—All Jigs.—All of the the various variousstyles stylesof of circle circle jigs jigs using usingaapivot pivotpoint pointcan canbebeadapted adapted for for use use on on the thebelt beltsander. sander.The The lower lower photo photo shows the the use use of of aa pivot pivotarm armfor forsegment segment work. In Inthis thisform formof ofjig, jig,the the work work. work s s [ 10 ]]

Jigs for for circles circlesand andcircucircularsegments segmentscan canbe beused used lar to to advantoge. advantoge.

STANDARD STANDARD FENCE

ARM ARM PIVOT ED PNOTE0 ON BOLT

WEK WORK V° .

' CLAMP STOP FOR ARM

„OPENING TO iETNWOCIK SUIT KO

Ets WtelT

A to A tilting tiltingfence fence and and pivot pivot arm arm are are aids to accuracy in production production work. work. accuracy in

SEGivav

CI4AMFERI NG JIG CHAMFERING JIG The sander sander affords affords one one of of the best best methods methodsof ofworkworking bevels. bevels.

Tilting Tilting Fence. Fence. — — For some types of sanding work, such as beveling, beveling, a tilting fence can be used to good advantage. Within certain limits the regular sander fence can be tilted by placing wedges wedges under the bracket arms. More extreme bevels can be sanded by using the simple fence shown in Fig. 1. This This consists consists of of aa wood fence of the same size as the the regular regular fence. The tilting fence is fastened to the regular fence by means means of of two two metal metal arms, arms, which are slotted to permit adjustments adjustments bebeof metal metal A thin but rigid strip of ing ing made. made. A screw-fastened to the underside of the regular fence, as can be seen in Fig. 2, supports the tilting fence above the sanding belt. belt. One of the metal arms can be fitted with a scale reading in degrees. degrees. Pivoted Pivoted Arm.—A Arm.—A pivoted arm, as shown in Fig. 4, can be used for various jobs where the end of the work is to be pointed or cut off on an angle. The The arrangement arrangement is is simply a fairly heavy piece of wood, which is bolted bolted to to the theregular regularsander sanderfence. fence. A washer between the pivoted arm and the fence permits the arm to be tilted tilted or or swung swung to to any anyposition. position. A A block clamped to the fence limits the amount of swing while a second block clamped to the arm furnishes furnishes a stop for the end of the work. In use, use, the the work is placed on the pivoted arm, one end

contacting the stop block. The arm is then tilted down to make the cut, Fig. 5, the operation being completed when when the arm comes in contact with the fence stop. stop. Beveling Beveling Jig. Jig. — — One of the cleanest and most accurate methods of beveling, beveling, especialespecially on short pieces and end grain, is done with the the use use of a simple vee-shaped jig. jig. Fig. 6 shows the general construction. The two two pieces pieces forming the vee groove are fitted together at right angles, and are sepseparated at the bottom a suitable suitable distance distance to to make the required cut. Fig. 7 shows shows the the jig jig in use. The work is simply simply placed placed in in the the vee vee groove and held there until the sanding sanding belt ceases to cut. If the jig is mounted mounted close to the belt, the width of the bevel bevel will be wider than in the case case where where the the jig is mounted mounted higher. higher. Even Even wear wear on on the the sanding belt is accomplished accomplished by by moving moving the the fence. Overcutting is impossible, and, providing the jig is parallel with the sanding belt surface, the bevel will be perfectly perfectly uniform and straight from one end of the work to the other. other. Use Use of of Forms. Forms.— — Sanding in production work can often be done more quickly quickly with with the use of forms. These are made from wood to the proper curvature, curvature, the the form form being ing screw-fastened to the regular sanding table. It is necessary in most cases to make a sanding belt to fit, although aa very very shallow shallow form can be used with the regular sanding sanding belt. belt. A A common shape is the circular circular form, form, (see Fig. 3, p. 12). This form is a portion of a true circle, hence, the work can be be pushed pushed along it since the curve is is the the same same at at all all

Curved any shape Curvedforms formsofofalmost almost any shape can be fitted fittedto tothe theregular regular sandsanding ing table. table.

points. points. Fig. Fig. 11 shows shows work work being being sanded sandedover overaacircular circular form. form. A A suitable suitablefence fenceisis made made up upand andclamped clampedtotothe the regular regularfence, fence,thus thusprovidproviding aa side side support supportfor forthe the work work and andinsuring insuringsquare square edges. The The irregular irregularform, form, Fig. 4, is not not a a part partof ofaa circle, circle, and andwork worksanded sanded over over this this type typeof ofform formmust must be set set down down at ataacertain certain position, position, placement placementbeing being controlled controlledby bymeans meansof ofaa stop stop block. block. Hollow Hollowforms, forms, Fig. 5, have have curves curveswhich whichdo do not not conform conformto tothe thebelt belt shape. shape. The Thebelt beltin inthis thiscase case run rather ratherloose loosesosothat that is run it will be be fashioned fashionedto tothe the same same shape shapeas asthe theform form when when the the work workpresses presses against against it. it.

SANDKV, F ORM ®

Forms Forms can canbe bebuilt builtup, up,the the work work surface surface being being covered coveredwith withplywood, plywood,as asshown showninin Fig. Fig. 2, 2, or or the theshape shapemay may bebe cut cut from from a solid piece piece of wood. The The preferable preferableabrasive abrasive belt belt for for use usewith withforms formsisisthe thecloth-backed cloth-backed style. A heavy heavy weight weight backing backingcan canbe beused used for for most most work, work,the theexception exceptionbeing being very very abrupt abruptcurves curveswhere where aa light light backing backing gives gives better betterresults. results.Forms Formsofofthe the type type shown shown in in Fig. 7, always always require requireaalight, light,flexible flexible belt belt in order orderto toconform conformtotothe the shape. shape. The The mannerin inwhich whichforms forms this kind work manner ofofthis kind work can can be be seen seen in inFig. Fig.6. 6.The Thefence fenceisisaligned aligned with form soso that with the the shaped shapedportion portionofofthe the form that the the work workwill will be bein inthe theproper proper position position when when it it is is pressed pressed against against the thefence fenceand and oLTw000 projected projectedinto intothe the belt. Under Underpressure, pressure, the the belt belt takes takeson onthe the same same shape shape as asthe the form form and andsands sandsthe the work work to to the thedesired desired shape. shape. A A certain certainnicety nicety in knowing knowing just justwhen when WORK to lift lift the the work workfrom from FENOE /0 the belt belt must mustbe beacacthe quired by bypractice. practice. MINIU BELT quired With With aa light-weight light-weight backing surfaced surfacedwith with 474 backing 511 " a fine-grit fine-grit abrasive, abrasive, FORM

Above, Above, using using aa grooved groovedform form toto sand sand aa round round edge. edge. Photo Photo at at leftleft shows a sand abrupt edge curves. a slashed slashed belt beltbeing beingused usedtoto sand abrupt edge curves.

sanding sandingof of practically practicallyany anymoulded moulded shape shape is is possible. possible. Where Where the theshape shapeof ofthe theform formisiscomposed composed ofof very very abrupt abrupt curves, type ofof belt. curves, slashed slashedbelts beltsshould shouldbe beused. used.This This type belt. as the the name nameimplies, implies,isisnot nota asolid solidsurface surface but but is is slashed slashed -inch wide. wide. Short Shortsections sectionsof ofthe the into into strips stripsabout aboutY8-inch 8Y belt belt are areleft leftuncut uncutand and these these uncut uncut portions portions serve serve to to hold hold the the numerous numerousnarrow narrow belts belts together. together. Slashed odd-shaped edges. Slashed belts belts are areideal idealfor forsanding sanding odd-shaped edges. This backing plate This type type of of work workisisdone donewithout withouta a backing plate hence table must bebe removed or the hence either eitherthe thesander sander table must removed or the work done doneon onthe theback backside. side.The The latter preferable work latter is is preferable for for occasional occasionalwork worksince sinceititisismuch much easier easier toto remove remove the table. InIn use, thethe belt is run the back backplate platethan thanthe the table. use, belt is run rather the work, when projected intointo it, it, ratherslack slackso sothat that the work, when projected as shown shown in in Fig. Fig.8, 8, will will cause causethe thebelt belttotoassume assume the the proper propershape. shape.Edges Edgesfinished finished inin this this manner manner willwill show show a very but forfor allall practical purposes very slight slightcurvature, curvature, but practical purposes the runs areare bestbest the effect effect is is aa right-angle right-anglecut. cut.Production Production runs done done with with the theuse useof ofthe thesander sandertable, table, since since this this proprovides aa rest proper contact restfor forthe thework workwhile whileinsuring insuring proper contact with toto remove thethe with the the belt. belt.ItItisisnecessary, necessary,ofofcourse, course, remove main main sander sandertable tablebefore before the the tilttilt table table can can be be used used [ 12 ]]

CHAPTER CHAPTERFOUR FOUR

OPERATING THE THE DISK SANDER Freehand Freehand Sanding. Sanding. — — Sanding Sanding on on PIVOT POINT the the disk disk sander sanderisisusually usuallydone done POINT"-, freehand, freehand,the thework workbeing beingheld held flat flat on the the table tableand andprojected projected into into the the sanding sandingdisk. disk.AAsmooth, smooth,light lightfeed feed should practiced. Avoid heavy shouldbe be practiced. Avoid heavy 0 pressure. pressure.Best Bestresults resultson oncurved curved TIVT ou S1.10E work work can can be obtained be obtained by going by going over times over the the work worktwo twoor orthree three times with with light light cuts. cuts.Sanding Sandingisisalways always 111111 iftwo„,,,r1114 Imen...done done on on the the"down" "down" side side ofof the the disk; disk; working workingon onthe theopposite oppositeside side I /LOCKING would, would, of of course, course,push pushthe thework work 7 ARM away away from from the thesanding sandingtable. table. Pivot Jigs.—Circular Jigs. Circular work work which which is to be be sanded sandedshould shouldalways alwaysbe beworked worked with with the the use useof ofaapivot pivotjig. jig.Top Topand and bottom bottom views of a simple simple jig jig are areshown shownin inFigs. Figs.11 and provide a a and 2. 2. Cleats Cleatson onthe theunderside underside provide positive positive stop stop against againstthe thefront front and and side side of of the The sliding strip can the standard standardtable. table. The sliding strip can be set isis locked inin set at at any anyposition, position,and and locked place place by by pushing pushingdown downon onthe thelocking locking lever, lever, the use, the end end of of which whichworks workslike likea acam. cam.InIn use, the the work workis isfirst firstband bandsawed sawed toto shape, shape, after after which which it it is is mounted mountedon onthe thepivot pivot point. point. The The sliding dissliding strip stripisislocked lockedatatthe therequired required distance tance from fromthe thesanding sandingdisk. disk. Pushing Pushing the the table table into intothe thedisk disksets setsthe thecut, cut, and and rotarotation tion finishes finishes the theentire entireedge edgetotoa aperfect perfect circular circularshape. shape.The Thejig jigcan can bebe clamped clamped to to the the sander sandertable tableororsimply simply held held with with one one hand rotates thethe work. hand while while the theother otherhand hand rotates work. Any other otherstyle styleof ofpivot pivotjig jigwill willwork work equally equally well, well, the the simplest simplestset-up set-upbeing beinga a brad braddriven driveninto intoa aboard board which which is clamped is clamped to the the sander sandertable tableatat the the required required distance distance from pivot from the thesanding sandingdisk. disk.An Anoverhead overhead pivot point, can bebe made point, as as shown shownat atthe theright, right, can made from circular circularsaw sawhold-down hold-down parts. This from parts. This type has the type of of jig jig is is fully fully adjustable adjustableand and has the advantage which can advantageof ofaavisible visiblepivot pivotpoint point which can be accurately work. accuratelyset setin inthe thecenter centerofofthe the work. Rounding Corners. Corners.—The The sanding sanding of of corcorA pivot ners inin that thethe A ners is is allied allied to tocircular circularwork work that isis almost aa necessity sanding circular pivotjig jig almost necessityinin sanding circular accurate work workisistotobe bedone. done. pieces if if accurate edge being being worked workedis ispart partofofa atrue true circle. circle.

‘.‘111411

k`ac."'"1---

—

—

SANDING DISK

•I PIVOT

LI NES

O

METHOD OF ROUNDING CORNERS

[13] [13]

A pencil onon the table pencil mark markisisthen thendrawn drawn the table of the the jig, jig, this thismark markbeing beingthe the same same disdistance asas the pivot tance from fromthe thepivot pivotpoint point the pivot point disk, asas shown point is is from fromthe thesanding sanding disk, shown in Fig. Fig. 4. 4. The The work workisisplaced placedagainst against aa guide edge ofof the jig, guide fastened fastenedto tothe therear rear edge the jig, as down as shown shown in in Fig. Fig.5, 5,and andisisbrought brought down on the with the the pivot pivotpoint pointin inalignment alignment with the pencil work rounds thethe pencil mark. mark.Rotating Rotatingthe the work rounds corner,see seeFig. Fig.6. 6.Fig. Fig.77shows showshow howthe thejig jig corner, table pencil lines asas a a table can canbe bemarked markedwith with pencil lines guide guide to to placing placingwork workof ofany anyradius. radius. Pointing Dowels. Pointing Dowels. — A A hole of the the same same diameter isisdrilled diameteras asthe thedowel dowelstock stock drilled through throughaa scrap scrap piece pieceof of wood wood which whichis is clamped atat the required clamped to tothe thesanding sandingtable table the required angle, isis angle, as as shown shownin inFig. Fig.1. 1.The Thework work pushed hole until it it contacts pushed through throughthe the hole until contacts the sanding sandingdisk, disk,after afterwhich which rotated the it it isis rotated to finish finish the the point. point. A circular Use of Miter Gage. Gage.—A circularsaw sawmiter miter gage can sanding can be be used usedto toadvantage advantageinin sanding square squareor ormitered miteredends. ends. Where Where miters miters areare being position is is asas being sanded, sanded,the thepreferable preferable position shown handlshown in in Fig. Fig. 2, 2, which whichpermits permitsbetter better handling than thanthe thereverse reverseposition position shown shown inin Fig Fig 3. Square Squareends endsare aresanded sanded by by projecting the projectingthe thework workalong along the miter miter gage gage until untilititcontacts contacts the the disk. disk. Sanding Sandingto toexact exactlength length can can be be done done by bypre-setting pre-settingthe the stop distance. stop rod rodat atthe therequired required distance The The rod rodis isfree freeto toslide slidein inthe the hole in in the the end endof ofthe thegage, gage,as as shown shown in in Fig. Fig. 4, 4, the theexact exactlength length being being set set when when the therod rodcomes comestoto a stop stop at atthe thebottom bottomofofthe thehole. hole. a The The beveling beveling of of square squareposts postsisis easily done done by by using usingthe themiter miter gage with with stop stop rod rodin inthe themanmanner ner shown shown in inFig. Fig.5. 5. Grinding Metal. Metal. — Finishing Finishing metals metals and andplastics plasticson onthe the disk disk sander sanderis practically practically the the same as similar similar operations operationson onwood woodwith with the the exception exceptionthat thatan analuminum aluminum oxide should oxide abrasive abrasivedisk disk shouldbe used instead insteadof of garnet. garnet. Large Work. Work.—Where Where the the work work being it it being sanded sandedis isso solarge largethat that cannot be beeasily easilyheld heldon onthe the cannot sander sandertable, table,an anauxiliary auxiliary wood wood table table of of suitable suitablesize sizeshould shouldbe be made, made, this thisbeing beingclamped clamped oror otherwise otherwise fastened fastenedto tothe thestand. stand. and and sanding sandingtable. table. Sanding with Pattern. Pattern.—In Sanding with In proproduction the duction work, work,sanding sandingwith with the use of a a pattern patterncan canbe beused used toto advantage advantage and and insures insuresperfect perfectwork. work. AA wood wood table, table, to to one side side of of which which is is screw-fastened screw-fastenedaathin thin but rigid rigidstrip stripofofmetal. metal. clamped place but isisclamped in in place over over the the regular regularsanding sanding table, table, asas shown shown in Fig. Fig. 2 2 on on the theopposite oppositepage. page.The Theguidguiding edge bebe about edge of of the the metal metalstrip stripshould should about I/ 8 inch I/8 inchfrom from the surface the sanding the surface ofof the sanding disk, disk, and andthe thepattern pattern should should bebe made made YeYe inch Anchor points inch undersize undersizeto tocorrespond. correspond. Anchor points permit to to thethe work. permitfastening fasteningthe thepattern pattern work. after after which whichthe thework workisisband band sawed sawed about about —

—

Above, Above, pointing pointingdowels dowelson onthe the disk disk sander. sander.Right, Right,how how toto use use the miter mitergage. gage.

Most Most work work of of this thisnature nature can can be be done done freehand, freehand, sweeping sweeping the the corner cornerof ofthe the work work across acrossthe theface faceof of the the sanding sandingdisk disktwo twoor or three three times timesuntil untilthe thededesired sired round roundisisobtained. obtained. More More accurate accurateresults resultsare are possible possible if if the the pivot pivotjig jigisis used used in in the themanner mannershown shown in the the drawings drawingsatatthe thebotbottom tom of of the the preceding precedingpage. page. The The sliding sliding strip stripisisfirst first locked locked in in place place at atthe thererequired quireddistance distancefrom fromthe the face of the the sanding sandingdisk. disk.

.

—

Square Square posts postsare areeasily easilybeveled beveledby by using using the thegage gageand andstop stoprad rad asas shown below. below.

—

—

[

1•1•11‘ inch inch outside outsidethe theedge edgeof ofthe thepattern. pattern. The The work work is is then thensanded sandedsmooth, smooth,the the pattern pattern being being held held in in contact contactwith withthe themetal metal guide, guide, as shown shown in in Fig. Fig. 1, 1, as asthe thework workisisproprojected into jected into the thesanding sandingdisk. disk. Sanding to Width.—Curved Width. Curved surfaces surfaces can can be sanded sandedto touniform uniformwidth width byby first first band band sawing sawing and andsmoothing smoothingone oneside, side,and andthen then using using aa spacer spacerpin, pin,asasshown shownininFig. Fig.3,3,toto set the the finish finishcut cuton onthe theopposite oppositeside. side.While While the photo photoshows showsthe thepivot pivotjig jigused usedfor forthis this the purpose, purpose,ititcan canbe beseen seenthat thatany any scrap scrap piece piece of wood with can bebe with one one corner cornerrounded rounded can clamped serve asas a a clamped to tothe thesanding sandingtable tabletoto serve guide. —

Use of Double Disk. Disk.

When working — When working small small wooden wooden or orplasplastic parts partsrequiring requiringtwo two grades grades of of abrasive abrasivefor for finishing, finishing, good good use use can can be be made madeof ofaa double double sanding sandingdisk. disk. This This is is made made by bycutcutting ting out out the thecenter centerofof the the coarser coarserdisk, disk,cecementing menting aasmaller smaller disk disk of of finer finer abrasive abrasive

Clean, Clean, accurate accurate work workininproducproduction tion runs runscan canbe bedone doneby bysanding sanding with withthe theuse use of ofaa potter, potter, SANDING DISK GUIDE 1,404

from from the the"up" "up"side sideofofthe the disk, disk, will will not not come come in in concontact tact with with the thesanding sandingsursurvArii face until until it it reaches reachesthe the "down" "down"side. side.The Theangle angle should should be be very veryslight slightand and is purposely purposelyexaggerated exaggerated in the ofof the illustrations illustrationstotoshow showthe themethod method working. working. A A smooth smoothfeed feedisisessential. essential.Any Any length length of of work workcan canbe behandled handledininthis this manmanner, through ner, or, or,short shortpieces piecescan canbeberun run through one after after another. another. Selection of Abrasive. Abrasive.—The The abrasive abrasiveused used on the the the disk disksander sanderwill willdepend dependupon upon the work. work. As As on on all all other otherabrasive abrasivemachines, machines, garnetisisused usedfor forwood woodwhile whilealuminum aluminum garnet oxide and and silicon siliconcarbide carbidedisks disksare are used used forfor metal. metal. Since Since the thedisk disksander sanderisiscommonly commonly employed genemployed for foredge edgework. work.the theabrasive abrasive generally can canbe besomewhat somewhatcoarser coarser than erally than forfor surfacing. A surfacing. A 1/2 1/2oror1/0 1/0disk diskcuts cutsrapidly rapidly toto a fairly fairly smooth smoothsursurface. Fine Fine cabinet cabinet (SANDING DISK (SANDING. DISK work, work, however, however, rerequires quires final finalsanding sanding _ with with aa 2/0 2/0 or or 3/0 3/0 disk disk so abrasive abrasive scratches scratches will not show. 015K

SECT/ON

DE

—

WORK

Above, Above, using usingaaspacer spacerpin pinto to sand curved curved work workto toexact exactwidth. width. Right,method methodused usedin insanding sanding Right, long, long, straight straightedges. edges. FENCE MOUNTI MOUNTED , SLIGHTANGLE ANGL in the the opening openingthus thuspropro- ATT SlI4I4T vided. vided. The The work workisisfirst first sanded on onthe theouter outerportion portion the sanded ofof the disk the disk and andthen thenwithout withoutstopping stopping the machine, is is finished finishedby bymeans meansofof machine, the the finer finerabrasive abrasivedisk. disk. Sanding Long Long Edges. Edges.— While the the disk disk sander sanderisisnot notparticularly particularly suited suited for forsanding sandinglong longstraight straight edges, good work work can canbe bedone doneby by using using the the set-up set-upshown shownininFigs. Figs. 4 and and 5. 5. A A wood wood fence fenceto towhich which is fastened fastened aahold-down hold-downblock blockisis clamped clamped to tothe thesander sandertable table atat the the required sanding requireddistance distancefrom fromthe the sanding disk. disk. The The wood woodfence fenceshould shouldbe be mountedat ataaslight slightangle angletotomake make mounted sure sure that thatthe thework, work,which whichisisfed fed

../woLo.Dover NOLODOVitrIN

401.,0•DOWN )210l,D.DOWN

W

II

—

[ 15 ]

CHAPTER CHAPTER FIVE FIVE

GENERAL GRINDING and and safest safestposition positionfor forgeneral general work. work. Work Work ground other posigroundin inthis thisposition, position,ororany any other position tion when when the thework workpoints pointstoto the the center center of of the the wheel, wheel, will will be be finished finishedwith withaasquare square edge. It It can canbe beseen, seen,Fig. Fig.5, 5,that thatwork work prepresented pointing sented in in any anyposition positionother otherthan than pointing to the the wheel wheel center, center,will willbe beground groundmore more oror less on a a bevel. bevel. Freehand Freehandgrinding grinding without without the done the use use of of aa rest restshould shouldalways alwaysbe be done on the the lower lower quarter quarterofofthe the wheel. wheel. Use of of Guides.—Guides Guides.—Guides clamped clamped to to the the regular accuracy and should be regularrest restinsure insure accuracy and should used on on all all precision precisionwork. work.Fig. Fig. used 77 isis anan example. ofof cut example. The Theexact exactbevel beveland anddepth depth cut is controlled controlled by bymeans meansof ofthe thesimple simplefence fence against against which whichthe thework workisisplaced. placed. FOLD The The grinder grinderplays playsan anIm• im• portant portantpart part inin hundreds hundreds of odd odd jobs jobsaround aroundthe the shop. shop. Smoothing Smoothing welded joints and cutting cuttingsheet sheetmetal metal and are typical examples. examples.

Safety Suggestions.—The grinder grinder is a safe safe tool tool to to operate operateproviding providing SHEET/ METAL a a few few simple simple rules rulesare arefollowed. followed Always use use the the guards. guards.IfIfguards guards are are not notprovided, provided,wear wearsuitable suitable goggles as a protection protectionagainst against flying fragments fragmentsof ofabrasive. abrasive.Keep Keep the the wheels wheels round roundby bydressing dressing whenever whenever required. required.Do Donot notforce force work work against againstaacold coldwheel, wheel,but but GRINDING WHEEL exercise exercise light light pressure pressureuntil untilthe the wheel becomes becomes warm. warm.Always Always use a a tool tool rest restwhen whenthe thework work permits. permits.Present Presentthe thework work toto the oror atat the wheel wheel either eitherstraight straightinin a a "drag" "drag"angle, angle, reserving reserving the the "gouge" "gouge"angle anglefor forsharpening sharpening and and other a a other operations operationsdemanding demanding WHEEL WW minimum minimum burr. burr. Odd Jobs. Jobs.—An — An almost almost endless endlessnumber numberofof odd odd jobs jobs are aredone doneon onthe thegrinding grinding wheel. wheel. Smoothing Smoothing aawelded weldedjoint, joint,as asininFig. Fig.1,1,isis typical typical of of this thisclass classof ofwork. work.Cutting Cutting thin thin metal 2,2, and metal by by first firstfolding foldingit,it,asasininFig. Fig. and then the fold, asas in in Fig. 3, 3, then grinding grindingthrough through the fold, Fig. is another anotherexample. example.Fig. Fig.66shows showshow howthe the edge of the the wheel wheel is is used usedto tonick nickrod rodstock stock preparatory chiseling oror sawing. Most preparatorytoto chiseling sawing. Most offhand offhand grinding grindingisisdone doneon onthe theface face ofofthe the wheel. When When grinding grindingisisdone doneon onthe the flat flat sides of a wear a straight straightwheel, wheel,use usecare caretoto wear the grooved the wheel wheel smooth smoothsince sinceaarough roughoror grooved side can jobs. can be be very verydangerous dangerouson oncertain certain jobs. Rest. — A level tool rest Position of Tool Rest.—A rest set set a a little little below below the thecenter centerofofthe thewheel, wheel, as as shown shown in in Fig. Fig.4, 4,is isin inthe themost mostpractical practical [ 16 ]

CHAPTER CHAPTERSIX SIX

HOW TO I SHARPEN TOOLS General. General.—— Two operations are necessary Two operations are necessary in sharpening mosttools: tools:(1) (1)the theedge edge in sharpening most isis

GRINDING WHEEL

ground groundto tothe theproper proper shape shape onon thethe grinder, grinder, (2) the the edge edge is is honed honedto toperfect perfectsharpness sharpness 0 on aa suitable wheel suitableoilstone. oilstone.The Thegrinding grinding wheel used used should shouldbe bean analuminum aluminum oxide oxide wheel, wheel, REMOVE NICKS BY PUSHING CHISEL about about 60-grit, 60-grit,and andof ofmedium medium hardness. hardness. irre.mort. sine WHEEL Keep Keep the the wheel wheel properly properlydressed. dressed.AArevolvrevolving disk disk type typedresser dresser(see (seepage page24) 24)can can bebe used used satisfactorily. satisfactorily.In Ingrinding, grinding, keep keep the the tool cool by constantly constantlydipping dippingininwater; water; temper temperis isbeing beingdrawn drawnwhen when blue blue spots spots apappear pear on onthe theedge edgeof ofthe thetool. tool.High Highspeed speed steel is best best ground groundentirely entirelydry, dry, using using a a very very light light feed feed and andstopping stoppingbebetween tween cuts cuts to toallow allowthe thetool tooltotoair air cool. cool. The Theuse useofofa a white white aluminum aluminum MOVE MOVE IsE L oxide wheel wheel will will permit permitaaheavier heavier EVEN Y EVENLY `A ACROSS CCESS feed without without overheating. overheating.

PV

0 0 PV Er TIL'T TOOL R TO OTIL' RT REST om INR o eau INR Bu E E iIv EEtb TO VR REE lb TO THE THE

FACE F

Wood Wood WoodChisels. Chisels.— —Wood Woodchisels chisels

OF

WHEEL. WHEEL

should should be be hollow hollowground. ground.Project Project the the chisel chisel straight straightinto intothe thewheel wheel to remove remove nicks, nicks,as asshown shownininFig. Fig 1; toto the 1; then. then.adjust adjustthe thetool toolrest rest the required requiredposition positiontotogrind grind the the bevel, bevel, Fig. 2, working working the thechisel chiselsquarely squarely across across the the face faceof of the thewheel, wheel,as as shown shown in in Fig. Fig. 4. 4. Worked Workedon onthe the face of the face the wheel, wheel, the the bevel bevel will will have have aa slight slighthollow, hollow,making makingitit easy to to hone hone to to aaperfect perfectedge edgesevseveral again eral times timesbefore beforeregrinding regrinding again becomes becomesnecessary. necessary. The Thebevel bevel

27

.

HOLLOW

GROUND

BEVEL

CLEARANCE

WHEN HONED WHEN HONED BEVEL BEVEL BECOMES BECOMESTOO 700 LONG LONG THE THE CHISEL CHISELSHOULD SHOULD BE REGROUND REGROUND BE

HONING HONINGREMOVES REMOVES THE THE BURR BURR AND AND BRINGS BRINGS CHISEL CHISELTO TO A KEEN KEEN EDGE EDGE

Tool Tool grinding grindingisisdone doneon on an aluminum aluminumoxide oxide wheel, with withthe theedge edge of of the tool tool against againstthe thedidirection rection of of rotation. rotation.Lower Lower drowing drowingshows shows honing honing methods. methods.

A 2e 20° BEVEL A BEVEL 20 20° BEVEL BEVEL A 30*BEVEL 30° BEVEL CAN USED CANBE BE USEDCRUMBLES STANDS STANDS UP UP IN CRUMBLES FOR SOFTWOOD SOFTWOOD ON ON HARDWOOD HARDWOOD HARDWOOD HARDWOOD

BURR

GRINDING GRINDINGFORMS FORMSAA BURR BURR ON ON CHISEL CHISELEDGE EDGE

A A Ye 10°BEVEL BEVELIS IS OBTAINED OBTAINED BY BY MAKING MAKINGBEVEL BEVEL TWICE. TWICE THE THE THICKNESS THICKNESS OF CHISEL CHISEL

THE THE BURR BURR CAN CAN 1. Ir BE REMOVED REMOVED 121BY BYHONINGTHE HONINGTHE CHISEL CHISELON ONTHE THE NAND HAND

[ 17 11

should should be be about about30 30degrees, degrees,this this being being obtained obtainedby bymaking makingthe the bevel bevel twice the the thickness thicknessof ofthe thechisel, chisel, as as shown shown in in Fig. Fig.5. 5.A A20 20 degree degree bevel can can be be used usedfor forsoftwood, softwood,but but this this thin thinwedge wedgewill willcrumble crumbleon on hardwood, inin Fig. 6. hardwood,as aspictured pictured Fig. 6 Honing. Honing.— —Either Eitheran analuminum aluminum oxide or or aa silicon siliconcarbide carbideoilstone oilstone will give good results resultsin inhoning honingor or whetting whetting the thechisel chiseledge edgeafter after grinding. grinding. The The sharpening sharpening stone stone should should always alwaysbe beoiled, oiled,the thepurpose purpose of this this being being to to float floatthe theparticles particles metal so so that thatthey theywill willnot notbebeof metal come embedded embeddedin inthe thestone. stone.Use Use a a thin thin oil oil or orkerosene. kerosene.Wipe Wipethe the stone stone after afterusing. using.Honing Honingisisnecesnecessary aa sary because becausegrinding grindingforms forms burr burrat atthe thechisel chiseledge, edge,asasshown shown in Fig. Fig. 7. 7. To To remove removethe theburr, burr, place place the the chisel chisel diagonally diagonallyacross across the the stone, stone, as asshown shownin inFig. Fig.8,8,and and stroke forward, stroke backward backwardand and forward,

GRIND PLANE WAD PLANC. IRONS AT 30° 30* AND ANDNONE HONE / AT 3S• 3S• IN THE JACK JACK PLANE PLANEBLADE BLADE IS SLIGHTLY ROUNDED ROUNDED

1

NONE G GRINDING, I ANGLE

CORNER CORNER .T/L411 1 /41 .1. 70.4111/41

SMOOTHING SMOOTHINGPLANES PLANESARE ARE GROUND GROUND STRAIGHT STRAIGHT

Jack plane plane irons irons should be slightly rounded; rounded; all all others others slightly are are ground ground straight straight with with a a slight slight round roundat atthe thecorners. corners.

in Fig. 11 on the previous page and this this is is the correct technique for chisels, plane irons, knives, etc. This method method gives gives aa clean edge with a minimum amount of labor. When the honed bevel becomes too whettings, Fig. Fig. 12, 12, long through repeated whettings, chisel should be reground. Figs. 13 and 14 picture the common method method of of hand hand honing. honing. Fig. 15 shows standard test for sharpness— the chisel should "bite" on the thumb thumb nail. nail. Plane Irons. Irons.—Plane Plane irons are sharpened the same as wood chisels. A bevel bevel of of 30 30 degrees and a honing angle of 35 degrees is satisfactory in most cases. cases. The The corners corners —

A 45. 45.

40t

r 25 25 • 35 35 °POR ° POR HARDWOOD WOOD

SKEW SKEW

KEEP EDGES KEEP EDGES ROUND FOR COVE CUTS COVE CUTS

GOUGE GOUGE

KEEP KEEP POINT POINT ON ON CENTERCENTERLINE

SPEAR PONT NT SPEAR PO

GRINDING GRINDING ANGLES ANGLES FOR FOR WOODTURNING WOODTURNING TOOLS TOOLS

FLAT FLAT NOSE NOSE

ROUND ROUND NOSE NOSE

PARTING TOOL TOOL

Bevels on wood turning turning tools should be be ground flat. Simple jigs, as at left, left, simsimas at plify work. plify the the work.

bearing do w n with both hands. The heel of the chisel should be a slight distance above the surface of the stone as shown in Fig. Fig. 9 9 Next, turn the chisel over and stroke the back on on the the stone. stone. making certain to keep keep the the tool perfectly level, as shown shown in Fig. 10. Alternate Alternate the the honing on bevel and back until the burr is completely removed. moved. It will now be noted that honing puts a secondary bevel on the chisel, as shown

of the plane iron should should be be slightly rounded. Mechanical Mechanical dedevices to hold the plane iron or or chisel at the proper angle when grinding are advantageous. advantageous. Wood Turning Tools. Tools. — Some wood turning tools tools are are not not holhollow ground. Instead, Instead, the the bevels bevels are perfectly perfectly flat flat and and should should be be kept flat during honing. honing. Any Any secsecondary bevel on a skew, for example, will prevent it from being used satisfactorily satisfactorily in in turning. turning. where the heel of the bevel must must act as a fulcrum. fulcrum. The Skew Skew Chisel. Chisel.—The The bevel of the skew chisel is double and has has an included angle of 25 25 to to 35 35 dedegrees. Grinding can be done on the disk sander, or on the side of a straight or recessed grinding wheel. The chisel can be held freehand, but better results will be obtained with a simple guide block, as shown in Fig. Fig. 1. 1. Holding Holding the the chisel first against one of the the beveled beveled guide guide blocks and then the other, as shown in Figs. 2 and 3. will bring each of the bevels to the required angle. In honing. honing. mainmaintain the same bevel. bevel. The Parting Parting Tool. Tool.—Make Make a suitable guide block to present the parting parting tool tool to to the the side of the grinding wheel. A grinding grinding wheel mounted on the circular saw offers offers aa convenient method of working working since since the the bevel angle can be set on on the the miter miter gage. gage. —

—

—

[ 18 ]]

The onon The gouge gouge is sharpened sharpened by byrolling rolling either wheel. either aa cup cupor orstraight straight wheel.

Lathe tool Lathe Tool Bits Bits—Lathe bits bits are aresharpened sharpenedoffhand, offhand, being being held held in inthe thehand hand to present presentthe thetool toolat atthe the proper properangle angleto tothe theside side ofof the the grinding grindingwheel. wheel.AAlight light touch touch on on the thegrinding grindingwheel wheel thatis isusually usuallyrequired required is all that to bring bringthe thebit bitto toa akeen keen edge. Maintain Maintainthe theoriginal original bevels, or, or, if if working workingblank blank stock, stock, follow follow the the angles angles for for 11/4 /4 inch bits inch bitsgiven givenin inthe the drawing drawingbelow. below.Handling Handling during duringgrinding grindingisissimplified simplified If the the bit bitis isheld heldin inthe thetool tool holder. holder. as asshown shownin inFig. Fig.66 Small Small abrasive abrasivesticks stickscan canbe be used used to to advantage advantagefor fortouchtouchup up sharpening, sharpening,es esppe eciciaa1-1when this this is is done doneduring during ly when the the course course of of aalathe lathejob. job. —

as shown shown in in the thelower lowerphoto photo on the the opposite oppositepage. page.The The Darting Dartingtool toolcan canalso alsobe beholhollow ground ground ifif desired. desired. Simplest of all The Gouge. Gouge.—Simplest methods methods of of sharpening sharpeningthe the gouge is to use use aa cup cupwheel wheel on the the lathe, lathe,rotating rotating the the chisel inside inside the the wheel, wheel,as as shown shown in in Fig. Fig. 1. 1. The Thecurved curved surface surface of of the thecup cupwheel wheel lessens the the amount amountof ofrolling rolling necessary necessary and andmakes makesgrind grind ing quite quite simple. simple.Lacking Lackingthe the cup cup wheel, wheel, the thesame samegeneral general method method can canbe beemployed employedby by turning turningaawedge-shaped wedge-shapedrerecess in a a block block of of hardhardwood. Fed Fed with with60-grit 60-grit abrasive abrasivegrains grainscombined combined with with grease, grease, the thewood woodblock blockworks worksjust just the the same gouge same as as cup cupgrinding grindingwheel. wheel.The The gouge can can also also be be ground groundby byrolling rolling the the bevel bevel onon the face face of of the the wheel, wheel,as asin inFig. Fig.22or oron onthe the the side of the the wheel. wheel. Fig. Fig. 3. 3. In Inall allcases casesthe theroll roll must must be be just justaalittle littleless lessthan than that that ofof a full a full half-circle. half-circle. Special Special sharpening sharpeningstones stonesare are required required forfor honing honing the thegouge. gouge.The Thebest besttype typeisishollow hollow on one one side side and andround roundon on the the other other side— side— made made especially especiallyfor forhoning honinggouges. gouges.Fig. Fig.4 4 shows this edge ofof this stone stonein inuse. use.The Theround round edge the the stone stone can canbe beconveniently convenientlyused used toto cut cut the the burr burron onthe theinside insideflat flat edge edge ofof the the gouge, gouge, Lathe freehand, the bitbit being Lathetool toolbits bitsare areground ground freehand, the being or purpose. or aa slip slip stone stonecan canbe beused usedfor forthis this purpose. mounted mounted in inthe thetool toolholder holder asas shown shown above. above. Drawing Drawing as shown shown in in Fig. Fig. 5. 5. below grinding angles bits. below shows shows grinding anglesfor forlathe lathetool tool bits. —

_i_ _}._ 'TOP VIEW TOP ViEN..

_A__ .1— -1— V V END

SIDE VIEW VIEW1 1

.•

••

14* TOPVIEW VIEW 14° TOP

merlon, merlon,

3.-

'° k.. SIDE VIEW VIEW R -1—

,...- OUNO ,,ROuNo

/ /

L1

GRINDING ANGLES ANGLES FOR FOR.LATHE LATHETOOL TOOLBITS BITS

BORING BORING TOOL TOOL

\' \ /

11 \ FINISHING FINISHING *4 .1...9'' )43° TOOL TOOL BIT BIT

+ _i__

TOP TOP VIEW VIEWAll11111111/ Allill. .:2"5-31-1 .: 5-31 r. .— 2"-1...r•—

,28, `,28,?T.Y6 ` ?T.Y6

Secr/aw Secr/oN

//, SiD VIEW

4

*.

.

LEFT LEFTCORNER, CORNERTOOL TOOL BIT BIT

e

TOP TOP VIEW VIEW I_33• 4-a2.....t......

WV

3S1..

—A-

......i rg; ?k,....,. . . . . . i),

SIDE WV., SIDE WV. , — -------f— f—,..1 \\._90. \ go ` .'"-

j

U

BEST BEST RESULTS RESULTSWILL WILLBE BEOBTAINED OBTAINEDBY BYUSING USINGEXACT EXACTSHAVES SHAVES SHOWN) SHOWN)

19 11 [ 19

ROUND ROUND EOGE EOGE GRINDINGWHEEL. WHEEI. GRINDING

NAIL NAIL SERVES SERVES AS GUIDE GUIDE TO TO BRING BRING EACH EACH TOOTH TOOTH INTO INTO GRINDING GRINDING POSITIONPOSITION-.

CLAMP P STOPS , SLIDE SLIOE RESIt REST, FEED PEED ..

ADE SAW BL BLADE LEVEL LEVEL WITH WITH LATHE LATHE CENTE,I, CENTC,,

AIL PIVOT

GaiNOTEETrIj44., AT Y4 PITCH IF IF SAW SAW IS IS GUMMED GUMMEDFREEFREEHAND, THE THEDEPTH DEPTHOF OF HAND, GULLETS GULLETS S ISFIRST FIRSTMARKED MARKED

2-1-6111/V

Above, method ofof gumming and Above, simple simpleautomatic automatic method gumming and grinding saw blades. Below, grinding a grindingcircular circular saw blades. Below, grinding a mortising mortisingchisel chiselon onthe thelathe. lathe.

canbe be Circular Saws. — Saw blades blades can — Saw gummed gummed free freehand handby bysimply simplyholding holding the the saw to to the the wheel. wheel. A A pencil pencilmark markshould shouldbebe made saw, asas shown made around aroundthe therim rimofofthe the saw, shown in Fig. Fig. 2, 2, to to indicate indicatethe thedepth depthtoto which which the the gullets gullets are areto tobe beground. ground. Grinding Grinding is is done wheel. done on on aa narrow, narrow,round-edge round-edge wheel. An automatic and automaticset-up set-upfor forgrinding grinding and gumming can canbe bemade madeon onthe the lathe with gumming lathe with the the use use of of the theslide sliderest, rest,asasshown shownininFig. Fig. 1. 1. The The grinding grindingwheel wheelshould shouldbe bedressed dressed to the and the slide the required requiredgullet gulletshape, shape, and the slide rest rest adjusted adjustedso sothat thatthe the wheel wheel will will bebe inin alignment tooth, as as alignmentto tocut cutaaquarter-pitch quarter-pitch tooth, shown shown in in the thecircle circleinset, inset,Fig. Fig.2.2.Grinding Grinding is done done by by feeding feeding the thesaw sawinto intothe thewheel wheel means of of the theslide sliderest restfeed. feed.AAnail nailinin by means the the work worktable tableprovides providesa astop stopsosothat that each each wet-or-dry The method of of wet-or-dryabrasive abrasivepaper. paper. The method tooth tooth is is accurately accuratelyaligned alignedfor for grinding. grinding. A A working workingisisshown shownin inFig. Fig.3,3,the thechisel chiselbeing being clamp base proclamp fitted fittedacross acrossthe theslide sliderest rest base pro- centered centeredon onthe thelathe lathetailstock tailstockcenter center and and vides aa stop stop for fordepth. depth.Each Eachtooth tooth is is ground ground projected abraprojectedinto intothe therevolving revolvingwheel wheeloror abrain turn. turn.The Thesaw sawshould shouldbebefree free from from gum gum sive-covered sive-covered wood wood form. form.A A square squareabraabrawhich setting which might might cause causean aninaccurate inaccurate setting sive stick stick or or file file can canbe beused usedtotoclean cleanout out against gullets against the theguide guidepin. pin.After Afterthe the gullets the the corners. corners. and and tooth toothfaces facesare areground. ground. the the position position of of Jointer Knives. Knives. — — Jointer Jointerknives knives the the slide slide rest restcan canbe bechanged changedtotogrind grind the the Grinding Jointer asas are ground groundon onan anangle angleofof3636degrees, degrees, backs the whole backs of of the theteeth. teeth.Throughout Throughout the whole are shown in in Fig. Fig. 11 on onthe theopposite oppositepage. page.When When operation circular saw operationof ofsharpening sharpeningthe the circular saw shown mountedin inthe thecutterhead, cutterhead, the the rear rear edge edge by grinding, grinding,caution cautionmust mustbebeused used toto prepre- mounted of the the bevel bevel should shouldbe beabout about1/1/16 inchfrom from 16 inch vent vent burning. burning. the the surface surfaceof ofthe thecutterhead, cutterhead,asas inin Fig. Fig. 2.2. Mortising Mortising Chisels.—The Chisels.—The internal internalsurface surfaceofof Since the the knives knives are arequite quitenarrow, narrow, it it is is the to to necessary the mortising mortisingchisel chiselshould shouldbe beground ground necessary for forgrinding grindingpurposes purposes toto make make a a an an included includedangle angleof of78 78degrees. degrees.The Thesimsim- holding holding block, block, this thisbeing beingmade madeby byrunning running plest plest method methodof ofworking workingisistotouse usea asmall small in aa saw saw cut cutwith withthe theblock blockininone oneofofthe the grinding grindingwheel wheelwith withend endshank, shank, dressing dressing thethe positions positions shown shownin inFig. Fig.3,3,depending dependingononthe the wheel to the The to the the required requiredangle. angle.Lacking Lacking the method method which whichwill willbe beused usediningrinding. grinding. The wheel, a a wood wood form formcan canbe beturned turned and and saw saw kerf kerf usua.ly usua.lywill willbe beaasnug snugfitfitfor forthe the then then coated coatedwith withglue glueand androlled rolledinin abrasive. abrasive, knife, knife, but butififany anylooseness loosenessisisapparent, apparent, the the or, or, the the form formcan canbe becovered coveredwith with120-grit 120-grit knife can can be be held heldsecure secureby bymeans meansofofscrews screws [20] [ 20 ]

I

KNIFE 11.l'INC1CVAR VAIRItfTiGn"tf•C'FIGn --KNIFE HOLDER HOLDER FOR FOR 2. 14A:140ING 2rOING FIG., FIG.,

KNIFE CUTTING'

VET

CJAW

SCREW SCREW

KNIFE KNIFE STRAIGHT HOLDERHOLDER STRAIGHT

Fig. 6 shows shows one one of of the the knives knivesbeing being sharpened The tool rest is is sharpenedon onthe thegrinder. grinder. The tool rest adjusted adjustedto tothe therequired required angle, angle, and and a guide a guide block block is is clamped clampedin inposition positiontotoinsure insure aa straight straightcut cutacross acrossthe theknife. knife. Each Each knife knife worked in inturn, turn,making making single, very is worked aa single, very light light cut. cut. A A strip stripof ofpaper paper isis then then pasted pasted to the the holding holdingblock, block,the thepurpose purpose ofof this this being being to to set set the thenext nextcut cutwithout withoutchanging changing the the original originalposition positionof ofthe theguide guideblock. block. Two or or three threevery verylight light cuts cuts will will usually usuallybring bringall all of the the knives knives to to aaperfect perfect edge. It It cannot cannotbe bestated stated too strongly strongly that thatabrasive abrasive cuts cuts on on high highspeed speedsteel steel knives knives must mustbe belight; light;heavy heavy cuts cuts will will invariably invariablyburn burn the the knife knife and andrender renderitituseuseless. The The method methodof ofgrinding grinding jointer jointer knives kniveson onthe thedrill drill press press with with aacup cupwheel wheelisis shown shown in in Fig. Fig. 7, 7, while while Fig. Fig. shows the the operation operationas as 8 8 shows performed performedon onthe thecircular circular saw. The The latter lattermethod methodcan can also be be used used in inconnection connection with with the the belt beltor ordisk disksander. sander. Whatever Whatevermethod methodisisused, used, best best results resultswill willbe beobtained obtained if the the grinding grindingisisdone donewith with successive light light cuts, cuts, taking taking each each knife knife in in turn turnuntil untilall all edges come up up sharp. sharp. Honing Honing Knives. Knives.—Grinding Grinding is not not always always necessary necessaryto to sharpen sharpenthe thejointer jointer since since STOP BLOCK careful careful honing honingat atregular regular intervals intervalswill willmaintain maintaina a sharp sharphead headfor forsome sometime. time. To hone hone the the knives, knives,partly partly cover cover aa fine fine carborundum carborundum stone stone with with paper paperso soititwill will REAR not not mark markthe thetable, table,and and TA8LE place place it it on on the thefront fronttable, table, as as shown shown in in Fig. Fig.9. 9. Turn Turn the the cutterhead cutterheaduntil until the the stone stone rests rests fiatfiat on on the the bevel, bevel, and andfix fixthe thehead headininthis this position position by clamping Whet clampingthe thebelt belttotothe thestand. stand. Whet the the knife knife by bystroking strokingthe thestone stone lengthwise lengthwise with with the the blade, blade,treating treating each each knife knife with with the the same same number numberof ofstrokes. strokes. Jointing Jointing Knives. Knives.—Knives Knives can can be be sharpened sharpened and and brought broughttotoa atrue true cutting cutting circle circle byby jointing their isis rejointing theiredges edgeswhile whilethe thehead head revolving. In In this this operation, operation,the the stone stone isis placed asas shown inin Fig. placed on on the therear reartable, table, shown Fig.

A number of different can different methods methods can be used in in grinding knives. In grindingjointer jointer knives. In case, grinding each case, grinding isisdone dry. Very Very done dry. lightcuts cutsmust mustbe light be taken takento toavoid avoid burning. inin rotation burning.Cuts Cutsare aremade made rotation on all all knives knives until untilaafinal final cut cut brings brings each of each of the knives to a perfect perfect edge. edge.

—

—

[ 21 ]]

REAR TAB[

10, the stone 10, and and the thetable tablelowered lowereduntil until the stone barely barely touches touchesthe theknives. knives.After After two two oror three three jointings jointingsof ofthis thisnature, nature, it it will will bebe necessary byby necessary to to recondition reconditionthe theknives knives grinding grindingin inorder ordertotomaintain maintain back back clearclearance. Setting Setting Jointer Jointer Knives. Knives.— — After After grinding, grinding, knives must inin the knives mustbe becarefully carefullymounted mounted the head ofofdoing head One Oneof ofthe thebest bestmethods methods doing this this is is with with aa magnet, magnet,as asshown shownininFigs. Figs.11 11 and and 12 12 on on the theprevious previouspage. page.An Anindex index mark markshould shouldbe bescribed scribed onon the the magnet magnet and and a toto the a stop stop block blockshould shouldbe beclamped clamped the front asas toto bring front table tableat atsuch sucha aposition position bring the the index index mark markininline linewith with the the cutting cutting edge of the the knife knife when whenititisisat atits itshighest highest point. is is point. The Theknife knifeisisplaced placedininits itsslot slotand and pulled pulled up upto tothe therequired required level level byby the the magnet, are tightmagnet, after afterwhich whichthe thesetscrews setscrews are tightened ened Once Once the theinitial initialset-up set-uphas hasbeen been made, made, this will found this method methodof ofadjusting adjustingknives knives willbebe found both and faster both accurate accurateand andconvenient, convenient, and faster than than where whereaaplain plainstraight straight edge edge is is used. used. Grinding Knives Knives in in Head.—Knives Head.—Knives can can be be ground the head byby groundwithout withoutremoval removalfrom from the head the comthe method methodshown shownon onthis thispage. page.The The complete cuts plete head headis is mounted mountedon onthe thejig. jig.Saw Saw cuts in the ofof the the pulley pulleyserve serveto tobring bringeach each the for grindknives into into the therequired requiredposition position for grinding. The The jig jig is is bolted boltedto tothe thedrill drill press press table, table, grinding table grindingbeing beingdone doneby byswinging swingingthe the table which which is is supported supportedon ona acolumn column collar. collar. AnAnother other method methodof ofgrinding grindingthe the complete complete head head is shown This shown in in the theheading headingtotothis thischapter. chapter. This makes makes use use of of aaflexible flexibleshaft shaftfitted fittedwith with aa small small grinding grindingwheel. wheel.The Thehead head isis fixed fixed at at the the proper properposition positiontoto maintain maintain thethe bevel bevel by clamping side ofof the clampingthe thebelt belttotothe the side the machine machine stand. stand. [ 22 ]]

Top, grinding grinding jig ilg in in use use Above, the the jig jig with with jointer head head removed. removed. jointer Pillow Pillow blocks blocks should should be be turned to exact diameter.

IY4/1

_L 3/4

1%8 3 r443-1 -15i-24 SCREW

CHAPTER CHAPTER SEVEN SEVEN

GRINDING SHAPER CUTTERS

F

F

Rake Angle. Angle.—The The rake rake angle angleof ofany anycutter cutterdetermines determines ,ts AsAs shown in Fig. 1, 1, ,ts shape shape and andother othercharacteristics. characteristics. shown in Fig. slanting line lineacross acrossaapiece pieceof ofwood woodisisnecessarily necessarily a slanting a longer longer than thanaastraight straight one. one. Applied Applied to to shaper shaper cutters, cutters, it can ofof the cutter workcan be be seen, seen, Fig. Fig.2, 2,that thatthe thelength length the cutter work- HOW ANGLE AFFECTS LENGTH ing on on an an angle, angle,B, B,must mustbe begreater greater than than if the if the cutter cutter worked worked straight straightacross across the the work, work, as as at at A. A. This This rake rake angle cutters and is greatest angle is is present presentin inall allshaper shaper cutters and is greatest when when knives knives are aremounted mountedinin aa moulding moulding head, head, as as shown shown in Fig. Fig. 3, 3, where where the theangle angleisisapproximately approximately 3030 degrees. degrees. It the rake angle, thethe greater It is is obvious obvious that thatthe thegreater greater the rake angle, greater MOULDING MOULoiNG 1-WING the the difference differencebetween betweenthe theshape shape ofofthe the knife knife and and thethe HEAD, - CUTTER CUTTER moulding moulding it it cuts. cuts. Amount of of Bevel. Bevel.—Knives Knives are are beveled beveled at atan anangle anglebebe30° RAKE tween seen, Fig. 6,6, that a a tween 30 30 and and45-degrees. 45-degrees.ItItcan canbe be seen, Fig. that bevel which the outer cutting which will will provide provideclearance clearanceatat the outer cutting circle may may not notbe beenough enoughtotogive giveclearance clearance the inner circle atat the inner cutting cutting circle. circle.Examination Examination ofofa a factory-sharpened factory-sharpened cutcutter ter will will show show that thatthe thebevel bevelisis A KNIFE SNAPS greatest edges ofof greatestat atthe theinner inner edges ---the the knife, knife, thus thusmaintaining maintaining the the SLOTTE SLOTTE D RAKE RAKE ANGLES ANGLES COLLA R COLLAR same same amount amountof ofclearance. clearance. e6L Portions Portionsof of the theknife knifeparallel parallel CLEARANCE CLEARANCE c‘"" o ;000.0.1tt nW ANA with with the the line line of of travel, travel,such suchas as 0 00 o o, the the sides, sides, demand demandonly onlyaaminminBEVEL imum imum amount amountof ofbevel bevelto toproproSIDE SIDE BEAL BEVEL vide clearance. clearance. Projected Shape. — The The reshape of of any any cutter cutterto to quired quired shape NO NO produce shape shapecan can produceaacertain certain U y CLEARANCE CLEARANCE - be obtained obtainedby bydrawing drawing the the SAME. SAME •A BEVEL BEVEL IS GREATGREATBEVEL IS moulding moulding full fullsize size on onaapiece piece EST ON INNER INNER of paper, paper,as asshown shownin inFig. Fig.7.7 B EDGE OF KNIFE KNIFE EDGE OF q the edge edge of of the the mouldmouldAlong the ing erect erect aavertical verticalline, line,A. A.BeBeAbove, factors factors governing governingthe theknife knife low the the moulding, moulding,draw drawa ahorhorshape. Left,aaknife knifeprojection. projection. shape. Left, Drawing Drawingbelow belowshows showsknife melting. melting. izontal izontalline, line,B, B,and and where whereA —

—

—

-'

.

•••••••—

II KN IFE HOLDER IS

ROUND ROUND IS EDGE EDGE WHEEL

II • • ;Li

I

N

FINISHED FINISHED KNIFE

gg

SLIP SLIP STONE STONE

IS

PATTERN

f

MOULDING

intersectsB Bdraw drawa aline, line, intersects C, at the the same same angle angle as as the the rake rakeangle angleof ofthe thecutter. cutter. Drop Drop lines from from the themoulding mouldingshape shape toto the the line line and.using using0 0as C C and. asaacenter, center,carry carrythese these lines around onnosite aroundto toline lineBBon onthe the onnosite side and and then thennroject project them them upward upward Lines Lines D located located at at all allpoints pointswhere wherethe the vertical vertical lines cut carried across cut the themoulding mouldingare are carried across the the center centerline lineand andestablish establish a series a series of of marks.which, which,when whenjoined, joined,show showthe the shape marks. shape of the toto cut the moulding the cutter cutterrequired required cut the moulding

J 1 ,T

PAPER PAPER PATTERN PATTERN WITH ALLOW. WITH ALLOW. ANCE MADE; MADE; FOR , FOR RAKE ANGL

[ 23 ]]

Si AR STAR WHEEL DRESSER.„4 DRESSER

WHEEL SHAPE FOR GENERAL WORK WORK -

'AuRi2 '61€ GRINDING WHEEL

TOOL. TOOL 0 REST REST ICK DRESSER

WHEEL DRESSING DRESSING WHEEL

The difference amounts to about 1/16 1/16 inch in depth where moulding moulding head head cutcutters are being plotted and about half of this for three-wing cutters cutters and and slotted collars. For average work, work, the the projected shape can be judged judged with with fair accuracy without drawing. The The basic rules to remember are (1) knives for cutting beads must be ground deeper, and (2) knives for cutting cutting coves coves must be ground fuller. fuller.

A star star wheel wheel dresser dresser is A is fast-cutting fast-cutting while while stick and diamond diamond dressers providefor for precision precisionwork. work. dressers provide

Making a Knife. Knife.—Figs. Figs. 8 to 15 on the previous page show show the the various various steps steps in making a pair of knives for use with slotted collars. The required shape shape is is a full half-circle, as shown shown in in Fig. Fig. 9. 9. A paper or metal pattern is made, as as shown in Fig. 8, and, following following the the basic rule, this is cut slightly deeper than the shape of a true circle. circle. Fig. Fig. 10 being transtrans10 shows the pattern shape being —

Use of Shaped Shaped Wheels.—Wheels Wheels.—Wheels can

be fashioned to any required shape by by ususing a suitable dresser. dresser. The revolving wheel type is the fastest cutCUTTER MOUNTED ting, but does not perON SPINDLE __ mit the precision which is possible with the silicon carbide stick type or the diamond dresser. The wheel type should be pushed straight into the wheel, while the the stick stick or or diadiaDRESS WHEEL TO mond work best at a drag angle, as SHAPE GRiNpING can be seen in Fig. 1. With a wheel wheel G`41TLI WHEEL G cuTTER cuTTER properly shaped, it is a simple simple matmat( ter to grind any cutter to the the same same contour. Fig. 3 shows a three-wing cutter being ground. Stops Stops and and LOCK LOCK .• CUTTER CUTTER AT AT guides insures all wings wings being being PROPER PROPER • POS ITION POSITION ground exactly the same. The use of a shaped wheel in a tool post grinder used on the lathe is shown shown in Figs. 4, 5 and 6. 6. The The cutter cutter is is (erred to the knife blanks. The outer turned to the required position for the straight bevel is then ground, ground, aa suitable suitable bevel, as in Fig. 6, and is then locked in method being as shown in Fig. 11 which this position by means of the index pin, pin, uses the lathe slide rest to set the required after which the cut can be be made. made. angle. The curved portion portion of of the the knife knife is is Sharpening Knifes. — Factory Factory - ground ground then ground on a round edge edge wheel, wheel, as as shaper knives with involute bevels should shown in Fig. 13, the tool rest being being adadbe sharpened by honing the flat side of the justed to provide the proper bevel. After cutting edge, as shown in Fig. 7. The ingrinding both knives, the shape is compared volute bevel will retain retain the the same same shape shape rereand checked. readjustments readjustments made made as as reregardless of metal removed from from the the back back quired, after which the bevel is lightly lightly side. Knives ground in the homeshop with honed, as in Fig. 15, to remove remove any any burr burr a straight bevel can be resharpened resharpened in in the the left by the grinding. On On certain certain shapes. shapes. same way, or, the bevel itself can can be be honed. honed. good use can be made of of aa cut-off cut-off wheel wheel to to Where the knife has an involute or curved remove excess knife stock, stock, thereby thereby eliminateliminatbevel, however, no grinding or honing ing tedious grinding. grinding. should be done on on the the bevel. bevel. —

[ 24 ]]

-

CHAPTER CHAPTEREIGHT EIGHT

GRINDING TWIST DRILLS Point Point Angle.—The Angle.—The two most most imim• -DRILL POINT POINT portant portantfeatures features ofofdrill drill grinding grinding CUTTING ;, e-• GAGE GAGE LIP are are (1) (1) the thepoint pointangle, angle,and and (2) (2)the the lip clearance. clearance.The Thepoint pointangle anglehas has been established establishedat at59 59degrees degreesfor for been general general work, work,and andthis this angle angle should should 9„, be maintained. maintained.ItItisiseasily easilychecked checked 9° OVER 59. with with aa drill-point drill-pointgage. gage.Gages Gagesinin a a variety variety of of styles styles can canbe bepurpurchased chased at ataanominal nominalcost, cost,or, or, the the worker workercan canmake makehis hisown own from from O sheet sheet metal. metal.The Themarkings markings on on the the edge, which which can can be beseen seenin inFigs. Figs.1, 1, 0 0 j 2 and and 3 3 need neednot notbe beexact exactsince since they they are areused usedonly onlyto tocheck checkthe the CORRECT CORRECT POINT POINTANGLE ANGLE POINT POINT POINTANGLE ANGLETOO TOO POINT ANGLE ANGLETOO TOO IS MOST MOST S $9°. $9°. THIS THIS IS GREATGREAT-DOES DOESNOT NOT SMALLSMALL-REQUIRES REQUIRES length length of of one one lip lip against againstthe theother. other. EFFICIENT EFFICIENTPOINT POINTFOR FORCENTER CENTER EASILY-DOES EASILY-DOES MORE MOREDOWER DOWERTO TO ALL. ROUND WORK ALL•AROVND WORK NOT TRACK IN PUNCH MARK OPERATE IN MARK OPERATE In In use, use, the thedrill drillbody bodyisisheld held against against the theedge edgeof ofthe thegage, gage, and and in in such suchaaposition positionthat that Point Point angle angle and and Ilp Ilp the the angular angularedge edgeisisover overthe the clearance clearance are arethe thetwo two cutting lip lipof ofthe thedrill. drill.The The cutting factors factors which whichenter enteriningage will then then show show whether whether to to the the grinding grindingof of or or not not the thepoint, point,or, or,rather, rather, drills. AA drills. point pointangle angle one edge edge of of the the point, point,isis"on "on of 59 59degrees degreesand anda of the the 59." 59."Fig. Fig.11shows showsaadrill drill lip lip clearance clearance of of from from with with the the correct correctpoint pointangle. angle. 12 12 to to I5-degrees I5-degrees give give Fig. 2 shows shows drill drillwith withpoint point best best results resultsfor forgeneral general POINT POINTON ONCENTER CENTERBUT BUT LIP LIPANGLES ANGLESTN TNEESAME SAME BUT POINT POINTOFF-CENTER OFF-CENTER LIP BUT LIPANGLES ANGLESOIFFERENT OIFFERENT angle angle which which is is too too great; great; work. Fig. 3 shows shows a a drill drillwith withaa point point angle angletoo toosmall. small.Besides Besidesbeing beingground ground HEEL REELOF OF CLEARANCE CLEARANCE to the the correct correctangle, angle,both both lips lips must must bebe CUTTING CUTTING LIP LIP exactly happens exactly the the same samelength. length.What What happens when oror ofof unwhen the the lip lipangles anglesare aredifferent different unequal equal length lengthisisshown shownininFig. Fig.4 4 and and Fig. Fig. 5. 5. CUTTING EletIT ING It It can can be beseen seenthat thatthe the resulting resulting hole hole will will LIP CUTTIN CuTTIN4 be out than thethe drill. out of of round roundand andlarger larger than drill. O CLEARANC CLEARANC V V Lip Clearance. — Like Like any any other othercutting cutting 1 1 DRILL DRILLPOINT POINTMUST MUST tool, there behind the there must mustbe beclearance clearance behind the HAVE CLEARANCE HAVE CLEARANCE 1/42I cutting can cut. This cutting edge edgebefore beforethe thedrill drill can cut. This AT AT EVERY EVERYPART PARTOF THE MOLE HOLE IT 0 THE ITCUTS CUBS clearance clearancecan canbe bereadily readilyseen seenon on aa properlyproperlyLI P CLEARANCE LIP CLEARANCE ground drill-point gage, grounddrill drillby byusing usingthe the drill-point gage, placing asas placing it it over overthe theheel heelof ofthe thepoint, point, LOTTING shown shown in in Fig. Fig. 6. 6. It Itwill willbe benoted notedthat that the the LIP angle lip angle here hereis is12 12degrees degreesless lessthan thanthe the lip angle, angle, and andthis thisisisthe theproper proper clearance clearance forfor • O ® 0 the the average averagedrill—from drill—from12 12toto15 15degrees. degrees. CORRECT- WRONG WRONG -HEEL CLEARANCE CORRECT-HEEL Clearance by holding WRONGClearancecan canalso alsobe beobserved observed by holding CLEARANCE WRONG- RUBS RUBS AT AT LIPS CUT AT AT X X RUBS AT X X-LIPS X-LIPS CANNOT CANNOTCUT CUT the the drill drillas asin inFig. Fig.88and andnoting noting the the differdifference between between the thelip lipand andheel heelof ofthe thepoint. point. against the conic partof ofthe theheel heelrubs rubs against the conic Two horizontal point are horizontalsections sectionsof ofaadrill drill point are part Fig. 11, 11, the the lips lips cannot cannotcut. cut. shown shown in in Fig. Fig. 7. 7. It Itcan canbe beseen seenthat that there there recess, Fig. Drill Grinding. Grinding.—With must must be be clearance clearancebehind behind the the cutting cutting lips lips With a fair fair understanding understanding at the at every every part partof ofthe theconic conicrecess recesswhich which the of point the worker point angle angleand andlip lipclearance, clearance, the worker drill drill cuts. cuts.With Withclearance clearanceproperly properly ground ground can can now now attempt attempttotogrind grind a drill. a drill. Even Even on, the cutting lips, leaving the drill drillcuts cutsatatthe the cutting lips, leaving though though the thetheory theoryhas hasbeen been mastered, mastered, it is it is every the lips in in still every part partof ofthe thepoint pointbehind behind the lips a drill still somewhat somewhatof ofaatrick tricktotogrind grind a drill the clear. clear. Fig. Fig.99shows showsthe thecorrect correctclearclear- offhand the the proper point. Ex-Exoffhand and andarrive arriveatat the proper point. ance. ance. Fig. Fig. 10 10 shows shows just justthe thereverse reverse ofof perienced perienced mechanics, mechanics,through through long long practice, practice, correct correctclearance—the clearance—thedrill drill rubs rubs at at thethe heel heel go through throughthe themotions motionsalmost almost mechanicalmechanicaland and the thelips lipscannot cannotcut. cut.Likewise, Likewise, ifif any any ly, grinding extremely grindingpoints pointswhich whichare are extremely ac—

—

[ 25 ]]

EIK

WHEEL,

REST

16 POSITION POSITION AT FINISH FINISH

Drawing Drawingabove above shows shows successive successive steps steps in in sharpening sharpening drill drill on on a a wheel wheel mounted in the the lathe. lathe.

A A simple simple method method of of grinding grinding utilizes utilizes a a guide block block to to set set the the point point angle. angle.

curate without the use of any any memechanical guides or other aids. aids. The The worker who only occasional grinds grinds a drill should always use some some form form of guide. Figs. 12 to 16 16 inclusive inclusive show one method of working. In this example, grinding is done on the lathe. The tool rest is is first first set set by by using the drill gage in the manner shown in Figs. 12 and 13. Now, if the lip of the drill is presented to to the the wheel while the body body of of the the drill drill is is at right angles to the rest, the point point angle will be exactly exactly as as required, required, as as can be seen in Figs. 14 and 15. From this starting position, the drill drill is is rorotated about one-sixth of a full turn, at the same time dropping the end about 12 12 degrees to give the required required clearclearance. The proper swing swing is is best best acacquired by swinging a properly-ground properly-ground drill against the wheel, keeping the ground surface in contact with the wheel and noting noting the the movements movements rerequired to produce produce this this surface. surface. Instead of dropping the drill to to grind the lip clearance, the drill can be swung horizontally to produce produce the the same effect. To grind drills in in this this manner, clamp a wood wood table table to to the the tool rest of the grinder and on this table nail a guide block at an angle of

59 degrees with the side of the the grinding grinding wheel, as as shown shown in in Fig. Fig. 18. 18. Mark Markoff off 2 series of parallel guide lines, each of these these being on an angle of 12 12 degrees degrees (the (the clearclearance angle) with the guide block, block, as as shown. shown. Now, if the cutting lip is placed against the side of the grinding wheel, with the body body of of the drill against the guide block, as shown in Fig. 19, the proper point angle will be obtained. From this position position the the drill drill is is rotated about one-sixth of a full turn, turn, at at the same time moving to a position parallel with the penciled guide lines, as shown in Fig. 20. Each lip is treated in turn, checking with the drill gage gage to see that both are the same exact length. length. If desired, the grinding grinding procedure can be reversed, starting at the position shown shown in in Fig. Fig. 20. This has the advantage that the surface being ground can be be seen at all times, but it has the disadvantage disadvantage of producing a heavier burr at the cutting lips. lips. In any case, care must be exercised not to to rorotate the drill too much, much, since over rotation will bring the lip on the opposite side into contact with the wheel, with the result that the grinding must be done done all over again. One or two light twists on each lip will usually bring bring the drill to a sharp sharr point. Touch-up grind ing can be done by grinding the lips lightlightly and rotating about one-eighth of a turn for clearance. T his will give a clean edge and can be done several several times before the condition shown in in Fig. Fig. 11 11 results, when the drill will demand grinding grinding FIN;31-4 POSITION overthe theentire entiresurface. surface. over [26 ] ]

OUNED EDG E ED WHEEL

DG

reness, ness, providing providingthe themetal metal is is removed from from the theimmediate immediatepoint point only. Where Wherethe theshop shopowner ownerdoes does Various Various mechanical mechanicaldrill drillgrinders. grinders. not not possess possess aa suitable suitableround-edge round-edge both both self-powered self-poweredand andfor forattachattachwheel, the the web web can canbe bethinned thinnedon on ment ment to to aastandard standardgrinder, grinder, can can bebe an an ordinary ordinarysquare-face square-face wheel. wheel. InIn purchased. drill purchased.Where Whereconsiderable considerable drill this this form formof ofweb webthinning, thinning,most mostofof grinding grindingmust mustbe bedone, done,ititisisusually usually the the grinding grindingisisdone doneon onthe theback back a a savings savings of of both bothtime timeand andmoney money of the the lips, lips, the thegrind grindbeing beingcarried carried to use use one one of of these these units. units.The The up onon up to to the thecenter centerofofthe thepoint point usual usual device device will will handle handledrills drillsfrom from each each side, side, as as shown shownin inFig Fig5.5. 1/32 1/32 to 1/2-inch 1/2-inch diameter. diameter. Drill for for Brass. Brass.—For For drilling drilling brass brass and and copper copperititwill willbe befound foundadvantageous advantageous squARE uA sqRE modify the the cutting cuttingedges edgesof ofthe thedrill. drill. to modify EDGE EDGE WHEEL WHEEL The The effect effect to to be beobtained obtainedisisshown shown somewhat somewhat exaggerated exaggeratedininFig. Fig.7,7,which which shows liplipis shows how how the thecutting cuttingedge edgeofofthe the ground groundoff. off.This Thismakes makesthe theedge edgescrape scrape rather ratherthan thancut, cut,and and reduces reduces thethe tendency tendency of the brass and other the drill drillto to"dig "digin" in"inin brass and other soft can be soft metals. metals.This Thisform formofofgrinding grinding can done done on on aa fine-grit fine-gritwheel, wheel,as asshown shownininFig. Fig. 6. Very aa Very little little metal metalisisground groundoff, off,just just few thousandths thousandths of ofan aninch, inch,and and for for this this reason the cutreason itit is is often oftenbetter bettertotoflatten flatten the cutting ting edge edge with with aasmall smallsharpening sharpeningstone. stone. Special Special Grinding. Grinding.—While While a a point pointangle angleof of 59 degrees ofof from 12 degrees and andaaclearance clearanceangle angle from to 15-degrees 15-degrees has has been beenfound foundbest bestfor foraveraverage work, work, best bestefficiency efficiencyisisobtained obtainedififdrills drills are toto bebe are specially-ground specially-groundfor forthe thework work done. done. For Forexample, example,fiber fibertakes takesa a drill drill with with a point point angle angleof ofbut but30 30degrees, degrees,while whilemanmanganese ganese steel steel requires requiresaa75-degree 75-degreepoint point angle. angle. The The countless countlessdrill-grinding drill-grinding variavariations tions now now in in general generaluse useare areofofundoubted undoubted Drilling Drillinginin brass brass and and other other soft soft metal metal is best is best done done with with value worker, but value to to the theproduction productionshop shop worker, but drillground ground the manner shown above. a drill inin the manner shown above. are are seldom seldomuseful usefulin inthe thehome homeshop. shop. Wheels for Drill Grinding.—As Grinding. As listed listed in in Web Thinning. Thinning.—As As shown shown in in Fig. Fig. 3, 3, the the ofof aluminum the appendix, appendix,the thepurified purifiedform form aluminum web of the the drill drillbecomes becomesthicker thickerasasit itapap- the (white in in color) color) makes makesthe thebest bestwheel wheel proaches proachesthe theshank. shank.ItItfollows, follows,therefore, therefore, oxide (white for grinding grindinghigh highspeed speeddrills. drills. not It It is is not as as that that the thepoint pointofofthe thedrill drill becomes becomes thicker thicker for oxide, but runs tough as as regular regularaluminum aluminum oxide, but runs as as the the drill drillisisground grounddown downand and resharpresharp-tough cooler and andis is practically practicallyself-dressing. self-dressing.SecSecened, it it cooler ened, necessitating necessitatingmore morepower powertotoforce force ond choice choice for forhigh highspeed speeddrills drillsand and first first through throughthe thework. work.To Topartly partly eliminate eliminate this this ond for general generaldrill drillgrinding grindingisisthe the regregheavy heavy end end thrust, thrust,the theweb webofofthe thedrill drill should should choice for ular type typeof ofaluminum aluminumoxide. oxide.InIn either either case, case, 4. This This operaopera- ular be thinned, thinned,as asshown shownininFig. Fig.4. the grit gritshould shouldbe beabout aboutNo. No.60 60and and the the tion tion is is usually usually done doneon onaaround-face round-facegrindgrind- the best wheel shape grade medium mediumhard. hard.The The best wheel shape ing wheel, wheel, the the drill drillbeing beingheld heldsosothat that the the grade recessed center, center,but butgood goodwork work can can bebe wheel cuts cuts in in the theflutes. flutes.The Theweb webcan canbe be is a recessed done on on the theside sideof ofaastraight straightwheel. wheel. thinned thickthinnedto toabout aboutone-half one-halfitsitsoriginal original thick- done Above, web thinning thinningwith withround-edge round-edge wheel. Above, wheel. Right,web webthinned thinned on square-edge wheel. Right, on square-edge wheel.

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—

—

—

[ 27 ]]

CHAPTER CHAPTER NINE NINE

BUFFING and POLISHING Metals, plastics plastics and lacquer. Metals, lacquer• coated surfaces surfaces can can be be brought brought to a smooth and flawless flawlessfinfinsmooth and ish by the application of suit• suitably-graded abrasive grains carried wheel. carried on on a polishing polishing wheel

LEATHER LEATHER CEMENTED CEMENTED AND AND PEGGED PEGGED IN INPLACE PLACE

0 7 '44 1: ' • SOLID SOLID LEATHER LEATHER POLISHING POLISHINGWHEEL WHEEL

GLUE GLUE IS Is APPLIED APPLI TO TO THE The Rion RionOF OF THE THE WHEEL WHEEL

A Polishing.—Polishing Polishing.—Polishingisisthe thegeneral general G2A RW I E 441/41 term termapplied appliedtotothe the complete complete process process of of removing removingtool toolmarks, marks, scratches, scratches, etc., from substances frommetals metalsand andother other substances to to produce produce aa high-luster high-lusterfinish. finish. The The process is divided divided into intothree threedistinct distinct parts. parts. First Firstof ofthese theseisisroughing. roughing. WHEE Roughing Roughingis isdone donedry drywith with abrasives abrasives tExtet yi5 COATED OLLING v in in grit gritnumbers numbersfrom from 40 40 toto 80. 80. Dry Dry RROLLING ABRASIVE GRAirtS GRAINS TESTING FOR ABRASIVE Tt5, .SLA TINNt.EFOR fining asasthe finingor orfine finewheeling, wheeling, thesecond second operation operationisiscalled, called,can canalso alsobe bedone done dry, done on aa greased dry,but butisisoften often done on greased wheel. Grits 120 Gritsused usedare arefrom fromNo. No. 120 to 180. Finishing, Finishing, also also called called oiling oiling and buffing, It It buffing,is isthe thefinal finaloperation. operation. is done with withfine finegrain grainabrasives abrasivescomcombined bined with withlard lardoil, oil,tallow, tallow, beeswax. beeswax. water. water. etc. etc. The Theexact exactsize sizeof ofgrain grain used in in all depend upall operations operationswill will depend upon the on the work and the the original originalfinish finish on the work and the desired desired finish finishon onthe thecompleted completedproduct. product. Polishing Wheels. Polishing Wheels.—The — The first firstoperation operationof of roughing roughingcan canbe bedone doneon onaasolid solidgrinding grinding wheel. and wheel. However, However,because becausethis thisisishard hard and has no flexibility, flexibility, polishing done polishingisisusually usually done on wheels made espeon leather leatheror orcanvas canvas wheels made especially cially for forthis thispurpose. purpose.IfIf the the work work is is aa flat flat surface, surface, a a solid solidleather leatheror orleather-covered leather-covered wood wood wheel wheel can can be be used; used; if ifthe thework work isis curved, demand a cemented canvas curved, ititwill will demand a cemented canvas wheel or has the required or other othertype typewhich which has the required flexibility.

[[ 28 28 ]]

LEATHERLEATHERCOVERED COVERED WOOD WHEEL

Setting Up Polishing Polishing Wheels. Wheels. — — The The old old abraabrasive is first first cleaned cleaned off off by applying applyingan anabrasive abrasive by stick stick about aboutthree threenumnumbers the bers coarser coarserthan than the abrasive abrasiveon onthe thewheel, wheel,as as shown shown in in Fig. Fig.8. 8. The The wheel is then then coated coated with with

THE RIPPLE RIPPLE BUFF BUCTI PARALLEL PARALLEL RUNS RUNS WITHEITHER wrn4 EITHER HARD WARDOR ORSOFT SOFT CONCENTRIC EDGE DEPENDING CONCENTRIC EDGE DEPENDING ON NOW NOW IT ITIS IS MOUNTED MOUNTED ON ON THE THE SPINDLE SPINDLE 7--,724p,u0 HARD

RIPPLE

METALTEETH

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A B T; ING KIZ691G WHEtL WHEE.1

BUFFING BUFFING WHEEL RAKE RAKE WHEEL WRONG WRONG

1 10

•• •• POSITION POSITION \ OF WORK WORK

LOOSE LOOSE WORKING WORKING AREA AREA

BUFFS

Buffing Buffingis isthe thefinal finalpolishing polishing operation operation and and is is clone with wheels. with soft softcloth clothor orleather leather wheels.

glue, as as in in Fig. Fig. 5, 5, after afterwhich whichititisis rolled abrasive rolled and andpounded poundedininthe the abrasive grains, grains, as asshown shownin inFig. Fig.6.6.OrdinarOrdinarily, one coat coat of of abrasive abrasiveisisenough, enough, but applied but two two or ormore morecoats coatscan canbebe applied to roughing roughingwheels wheelsto tolengthen lengthentheir their period period of of service. service.Each Eachcoat coatshould should be completely completely dry drybefore beforethe thenext next isisapapplied. plied. After Afterthe thewheel wheelisisdry, dry,ititshould should bebe balanced, heavy balanced,as asshown shownininFig. Fig.7.7.IfIfany any heavy RIGHT POSITION POSITION \ RIGHT OF WORK WORK spots spots are arefound, found,they theyshould should bebe corrected corrected by nailing nailing small smallpieces piecesof oflead leadtotothe thewheel wheel life ofof the wheel. grains and andshortens shortensthe the life the wheel. or which gives the or by by any anyother othermethod method which gives the grains Apply grease grease or orother otherlubricant lubricant if if required. required. desired desired result. result. occasional application applicationofoflump lump pumice pumice Animal hide hideground ground An occasional Concerning Glue. — Animal clean the the wheel wheelififititbecomes becomesclogged. clogged glue is commonly commonly used used for forapplying applyingabraabra- will clean Work systematically systematicallyover overthe thearea area toto bebe sives to polishing polishing wheels. wheels. It Itshould shouldbe be Work polished, inspecting inspectingthe thework workfrequently frequently forfor soaked soaked in in cold coldwater waterfrom fromtwo two toto four four polished, defects which which must mustbe beworked workedout. out. hours, hours, and andisisthen thenbrought brought toto a heat a heat of of 140 140 defects Fine Wheeling. Wheeling.—Fine Fine wheeling wheeling is is done done the the degrees degrees F. F. in in aasuitable suitablegluepot. gluepot.Use Usedefinite definite same as as roughing roughingexcept exceptfiner finerabrasive abrasive weights parts, byby same weights of of water waterand andglue. glue.Equal Equal parts, grains are areused. used.Also, Also,atatthis thisstage stage there there weight, weight, is is the the right rightconsistency consistencyfor forabrasive abrasive grains polishing greateruse useof ofthe thesofter softer polishing grains grains from fromNo. No.20 20to toNo. No.50. 50.Finer Finergrains grains is a greater and frequent frequentuse useofofgrease greaseoror other other demand 70-grit takes demandaathinner thinnerglue. glue.60 60toto 70-grit takes wheels, and lubricantto toprevent preventthe the wheel wheel from from clog. clog. a 40-60 mix (glue-water), (glue-water),80 80 to to120-grit 120-grittakes takes lubricant ging. 33-67, while very very fine fine abrasives abrasivesfrom from150 150toto 220-grit glue toto 8080 220-grit will will require require20 20percent percent glue Buffing.—Buffs Buffing.—Buffs are are made madeof ofdisks disksof ofmusmuspercent set atat least percentwater. water.Wheels Wheelsshould should set least lin, felt, flannel, flannel, leather. leather.etc., etc.,and andare are sewed sewed 48 hours hours before beforethey theyare are used. used. Instead Instead of of in aa wide wide variety varietyof ofpatterns patterns shown asas shown inin using special using glue, glue, many manyworkers workersprefer prefer special Figs. iu iu to to 13, 13, to to produce producehard hard oror soft soft polishing polishing cements cementsmade madefor forthis thispurpose. purpose. wheels. The The loose loose buff buff (stitched (stitchedonce once These These have have the theadvantage advantageofofbeing beingalready already around shown inin Fig. 10,10, is is aroundthe thehole) hole)asas shown Fig. a mixed, drying time. mixed, and andrequire requirea ashorter shorter drying time. popular popularstyle. style.The Theripple ripple buff buff can can bebe made made runwith witheither eithera ahard hard oror soft soft edge edge byby How to Polish. — The The work workis ispresented presented to run asas shown inin reversingititon onthe thespindle, spindle, shown freehand the outer freehandto tothe thewheel wheeland andon on the outer reversing 9. As As in in polishing, polishing,the thework work must must be quarter wheel surface, asas shown quarterarea areaofofthe the wheel surface, shown Fig. 9. be done on on the the lower lowerside sideof ofthe thewheel, wheel,as as in Figs. Figs. 1 1 and and15. 15.Avoid Avoidusing usingtoo toomuch much done asas shown shown in in Fig. Fig. 18. 18. Work Workpresented presented shown oressure. the abrasive oressure.as asthis thistears tearsnut nut the abrasive shown —

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either either with withor orwithout withoutthe the backing backing plate plate depending ofof the work. InIn dependingon onthe thenature nature the work. respects,the thebelt beltcan canbe betreated treated the all respects, the same same as as aa polishing polishingwheel, wheel,and andcan canbebe coated coated with buffing compound. with abrasive abrasivegrains grainsoror buffing compound. Buffing compounds. compounds Buffing Compounds. Compounds. — Buffing are are various variousnatural natural abrasives, abrasives, such such as as emery, emery, tripoli, pumice, pumice,crocus, crocus,lime limeand and rouge, tripoli, rouge, which which are arecombined combinedwith witha asuitable suitable wax wax or or grease which can bebe grease to to form formaamixture mixture which can readily buff. The readily applied appliedto tothe therevolving revolving buff. The compound lightly and compoundshould shouldbe beapplied applied lightly and frequently work profrequentlyto tothe thebuff buffasasthe the work progresses, gresses, as as shown shownin inFig. Fig.19. 19.The Theworker worker can can make makehis hisown ownbuffing buffingcompounds compounds byby melting melting beeswax beeswaxin inaadouble doubleboiler, boiler, asas . I shown shown in in Fig. Fig. 20, 20, and andthen thenadding adding the the I abrasive abrasiveuntil untilaathick thickpaste paste is is formed. formed. The The molten molten mass mass is is then thenpoured pouredininto cardboard cardboardtubes, tubes,asas inin Fig. Fig. or made madeinto intocakes, cakes,and and 21, or BEESWAX E SWAX when when cold cold is is ready readyfor foruse. use.All All of the abrathe various variousstandard standard abrar e) ) sives can can also also be be purchased purchased ready ready made. made.Very Veryfine fineabraabrasives can can be be bonded bondedwith withoil oil or or water. water. Other Otherthan thanpolishing polishingmetals, metals, ro 0 buffing buffing wheels wheels charged chargedwith with MIX ABRASIVE WITH WA% suitable suitable compounds compoundsare areused used for for polishing polishingplastics, plastics,lacquered lacquered surfaces, surfaces, bare barewood, wood,ivory, ivory, horn, horn, etc. etc.In Inall allcases, cases,such such easily-obtained easily-obtainedabrasives abrasivesas as POUR POUR INTO INTO CARDBOARD.. CARDBOARD pumice pumice and androuge rougewill willusually usually CYLINDER CYLIN DER do good good work. work. Benzine Benzineor or lacquer lacquerthinner thinnerwill willremove remove any any film film of of compound compoundleft lefton on the the work work after afterbuffing. buffing. —

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buffingcompound compoundisisapplied applied lightly and The buffing lightly and frequentlyto tothe therevolving revolvingbuffing buffing wheel. frequently wheel.

by the the dotted dottedlines, lines,Fig. Fig.18, 18,will will be torn tornfrom fromthe thehands hands with with conconsiderable siderableforce. force.The Theedges edgesof ofthe the buff buff should shouldbe bekept keptclean cleanand and round. round.Frayed Frayededges edgescan canbebedressed dressed down down with with aabuffing buffingwheel wheelrake, rake, Fig. 16, while the the buff buffis isrunning. running. Any rough roughedge, edge,such suchas asaahousehousehold toto hold food food grater, grater,can canbe beused used dress dress buffs. buffs. Strapping Belts. Strapping Belts.—Belts Belts of muslin, muslin, felt, leather, the leather,etc., etc.,can canbe berun runonon the belt inin Fig. belt sander, sander,as asshown shown Fig. 14 14, —

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BUFFING AND POLISHING POLISHING SCHEDULES SCHEDULES MATERIAL MATERIAL

METHOD METHODOF OFWORKING WORKING

ALUMINUM ALUMINUM

Polish at at 5,500 5,500 s.f.m. s.f.m. using usingNos. Nos.80, 80,120 120 and and180-grits. 180-grits. All wheels over Polish over 120-grit 120-grit should should be be well well greased. greased. Buff at first buffing at 7,500 7,500 s.f.m., s.f.m., using usingtripoli tripolifor forthe the first buffing and finishing finishingwith withred redrouge. rouge. and

BRASS

Polish Polish at at 6,000 6,000 s.f.m. s.f.m.using usingNos. Nos.80, 80,120 120 and and 180-grits. 180-grits. The The 80-grit 80-grit is necessary necessary only for tripoli oror emery at aatspeed of about 5,500 s.f.m. for rough roughcastings. castings.Buff Buffwith with tripoli emery a speed of about 5,500 s.f.m.

COPPER COPPER

Same schedule schedule as as brass. brass. Fine-grit Same Fine-gritwheels wheelsshould shouldbe begreased. greased. Avoid heavy heavy pressure quickly and holds heat longer than other metals. pressuresince sincecopper copperheats heats quickly and holds heat longer than other metals.

CAST IRON IRON

Use grits grits 120, 120, 150 150 and and 180. 180. The The two two coarser coarsergrits gritscan can be run dry.Buff at be run dry. at 7,500 7,500 s.f.m. Buff with with 220 220 to to 240-grit 240-gritsilicon siliconcarbide carbideapplied applied a greased wheel. toto a greased ragrag wheel.

LACQUERED LACQUERED SURFACES SURFACES

Use a lacquer lacquersuitable suitablefor forbuffing. buffing. Buff at at 6,000 6,000 s.f.m., s.f.m., using usingany anyreliable reliablebrand brand of lacquer lacquer buffing buffingcompound. compound.

NICKELED NICKELED SURFACES SURFACES

Buff at lime. at 7,500 7,500 s.f.m. s.f.m. using usingtripoli tripoliand and lime. A perfect perfect finish finishis isnecessary necessaryififthe the work work is is to to be be chromium chromiumplated. plated.

PLASTIC PLASTIC

Polish Polish with with 280-grit 280-gritsilicon siliconcarbide. carbide. Buff with with 400 400 and and500-grit 500-gritsilicon siliconcarbide carbide on greased greased wheels. wheels. Finish Finish with with red redor orgreen greenrouge. rouge.

STEEL STEEL

Polish Polish at at 7,500 7,500 s.f.m., s.f.m.,using usingaluminum aluminum oxide oxide grits grits Nos. Nos. 9090 and and 120 120 dry dry andand 180180 greased. Buff greased. Buff with with tripoli tripolior ora a very very fine fine grit grit aluminum oxide. aluminum oxide. For a mirror mirror finish, finish, buff buff with with green greenrouge. rouge. For For satin satin finish, finish,buff buffwith withpumice pumiceon on Tampico aa Tampico brush. brush.

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CHAPTER TEN TEN

HOW TO USE SANDING DRUMS drumsof ofvarivariSanding Sanding Drums.—Sanding Drums.—Sanding drums ous sizes are are extensively extensivelyused usedfor foredge edge work, and andcan canbe besatisfactorily satisfactorily worked work, worked onon the oror directthe drill drillpress, press,lathe, lathe,flexible flexibleshaft, shaft, directcoupled size most coupled to to aamotor motorshaft. shaft.The The size most commonly commonly used usedmeasures measures33inches inchesinindiamdiameter atat a speed of of about eter and andshould shouldbe berun run a speed about 1800 1800 R. R. P. P. M. M. Within Withinreasonable reasonable limits, limits, the the higher higherthe thedrum drum speed speed the the smoother smoother thethe finish. finish. Excessive Excessive speed, speed, however, however,causes causes overheating, finoverheating,and, and,where wherewood woodisisbeing being finished, pitch from ished, the the heat heatextracts extractsa agummy gummy pitch from the the work workwhich whichquickly quicklyclogs clogsthe theabrasive abrasive sleeve. sleeve. Drums used usedon onthe the Sanding Sanding on onLathe. Lathe.— — Drums lathe sh,sit, tkstks or or screwlathe are arefitted fittedwith withtaper taper screwon fittings the lathe fittings to to permit permitfastening fasteningtoto the lathe headstock. headstock. Sanding Sandingcan canbe bedone donefreehand, freehand, but asas inin but where whereedge edgework workisisbeing beingdone, done, Fig. 1, aa vertical verticalsupport supportgreatly greatly simplifies simplifies the the work. work.Drums Drumswith withtaper taper shanks shanks should should be safeguarded safeguardedfrom fromcoming comingloose looseby bysupsup- A vertical vertical sanding toto the bed of of thethe lathe sandingtable tableclamped clamped the bed lathe porting tailstock, using a a portingthe theend endwith withthe the tailstock, using permits ofof curved edges. permitsaccurate accuratesanding sanding curved edges. sixty degree degree plain plaincenter. center.Another Another Wee i:n!F method method of of fastening fastening uses uses aa 1/4 1/4inch inch diameter into diameterstud studwhich whichisisturned turned into the the hole hole in in the theend endof ofthe theshank, shank, the the opposite oppositeend endbeing beingheld heldsecure secure by means means of of aa washer washerand andwing wing nut, nut, as as shown shownin inFigs. Figs.22and and3.3.

Taper Tapershank shankdrums drums are are securely securely held held by by means means of a stud stud fitting fittingthrough through the the headstock. headstock.

Narrow-Face Narrow-Face Drums. Drums. — Standard Standard sanding sanding drums drumsmeasure measure 3 3inches inches long and onon and have haveaaprojecting projectingnut nut the the free free end. end.Narrow-face Narrow-facedrums drums are are 11 inch inchwide wideand andare areflush flush onon the the bottom, bottom,the thetightening tighteningnut nut bebeing on on the the shank shankend, end,asasshown showninin Fig. Fig. 4. 4. All standard standard operations operations can can be be done donewith withthese thesedrums, drums, the the face face width width of of 11 inch inchbeing beingsufficient sufficienttotohandle handle average average 3//4 inch inch thick thickwork. work.The Theflush flushbotbottom tom also also permits permitsthe thefinishing finishingofofinside inside corners, When corners,as asshown shownin inthe thelower lowerphoto. photo. When doing toto doing this this kind kindof ofwork, work,ititisisadvisable advisable mount mount the thesleeve sleeveso sothat thatititprojects projects about about inch asas inch beyond beyondthe thebottom bottomofofthe thedrum, drum, shown the shown in in Fig. Fig. 5, 5, in inorder ordertotoprevent prevent the drum drumbottom bottomfrom fromburning burning thethe work. work. NarNarrow-face a special tri-trirow-face drums drumsare arefitted fittedwith with a special shape mounting in in shape shank shankwhich whichpermits permits mounting either iiinch either collets chucks, inch colletsororthree-jaw three-jaw chucks, as shown shown in in Fig. Fig. 6. 6. —

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spindle. A second table table can can be be used, or the regular table can can be be swung around under the drum. drum. Fig. 3 shows work being sanded with the drill table in a vertical vertical position. Furniture legs which are are a round column can fitted to to a to be fitted be cut to shape by using a sanding sanding drum in this manner. manner. Pattern Pattern Sanding.—The Sanding.—The most troublesome feature in in edge edge sandsanding with a drum is is that that if if the the operoperator holds the work a moment too long at any one spot, the the drum drum imimmediately cuts into the work, causing a ridge. This can be avoided and perfect work done if a pattern pattern is used as a guide, as shown in Fig. 7. The pattern is a full-size template of the desired shape, with edges perfectly finished. finished. It It is fitted with two or more anchor points. These can can be be wood screws, with the projecting end filed to a thin, flat p o i n t, as shown shown in in Fig. Fig. 4. 4. The work is fitted to the pattern, the anchor points holding it in place. Band sawing is then done, keeping about -1'-g inchoutside outside about 116 inch the pattern, as shown in Fig. 5. Fig. 6 shows shows how the drill press table is fitted with a hardhardwood or metal metal ring. ring. When the pattern is pressed against the collar, the drum cuts the work down to the same same size as the pattern. pattern.

Above, using a sanding sanding table. table. Right, Right, drum mounted direct to to motor motor shaft. shaft. mounted direct

Sanding on Drill DrillPress. Press. — Drums used on the drill drill press press run in a vertical position most useful for average average work. work. Good use can be made of fences, pivot pins, and other jigs to guide guide the the work work alalthough most operations can be done freehand. Small drums will work inside inside the the opening in the drill press press table, while larger sizes can be worked by swinging swinging the the drill table to one side. Fig. Fig. 1 sanding 1 shows a useful sanding table. It has holes in it to accommodate the various size drums, so that the whole surface of the drum can be utilutilized by projecting the drum through the hole provided for it. Another worthy idea is shown in Fig. 2, which shows how a sanding drum can be carried on the lower end of the drill press motor

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Pattern sanding, as as shown shown below, eliminates ridge marks when irregular irregular curves be. curves are be. ing worked. worked.

CHAPTER CHAPTER ELEVEN ELEVEN

How to Use CUT-OFF WHEELS abrasivewheels wheelsin in General General Use.—Cut-off Use.—Cut-off abrasive thicknesses thicknesses from from1/32 1/32to to5/32-inch 5/32-inchare areused used for for sawing sawing all all types typesof ofmaterials materialsincluding including metals, metals, stone, stone,and andglass. glass.The Thewheels wheelsare are resinoid, resinoid, shellac shellacor orrubber rubber bonded bonded to to perpermit mit a a slight slightmeasure measureof offlexibility. flexibility.The The work oror dry. The work can canbe bedone doneeither eitherwet wet dry. The wet method methodis isconsiderably considerablyfaster faster and and shows less wheel wheel wear, wear,but butthe thedry dry method method of cutting average cutting is is quite quitesuitable suitablefor for average homeshop homeshop work. work.The Thesurface surface speed speed ofof dry dry wheels should should be be about about7,500 7,500feet feetper perminminute, ute, while while wet wet wheels wheels show showbest bestresults results at at 6,000 s.f.m. Wheels can can be be run run on on any any spindle are properspindle providing providingonly onlythat thatthey they are properly mounted mounted and andwell wellguarded. guarded.InIn every every case, case, however, however, washers washersof of blotting blotting paper papershould should be used used on on either eitherside. side. These These are aregenerally generally furnished furnishedas aspart partofofthe the wheel.

LAMP

Above, anan abrasive Above, cutting cuttingsteel steeltubing tubingwith with abrasive Cutting Cuffing Thin • Wall Wall wheel on the the circular circularsaw. saw. Tubing. — One One of of the the most most common commonuses usesof of the the miter mitergage gageclamp clampattachment, attachment, abrasive abrasivecut-off cut-offwheels wheels as shown shown in in the thephoto photoand anddiagram diagram is the the cutting cuttingof of tubing. tubing. above. above. Notice Notice that thatthe thework workisis In In this this operation, operation,as as supportedon onboth bothsides, sides,a a slot slot inin . 11 supported done done on on the thecircular circular the the block block permitting permittingpassage passage ofofthe the saw, it it is is advisable advisableto to wheel. hold hold the the tubing tubingin inaa Solid stock suitable suitable vee vee block, block,the the Cutting Cuffing Solid Sfock. Stock.—Solid block block being being held heldto tothe the is cut cut in in much muchthe thesame samemanner manner miter miter gage gageby bymeans meansofof ill6t.......i...._ - .1 as as wood wood is is sawed sawed on onthe thecircular circular saw. Some Some form formof of guide guideis isalalSome form form of of guide guidemust mustalalways be used used when when cutting-off cutting-off ways necessary. necessary.A Asuitable suitableguard guard on the gr,cler. gr,cler. should should be be used. used.If Ifaaspecial specialabraabra—

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at any dime store. The guard plate plate is used in actual operation operation and and is is removed in the picture only only to to show how the bottom of the the wheel wheel runs in the coolant. The use of the grinder for cutting-off has one serious drawback in in that that the the proprojection of the motor limits the size of stock which can be be worked worked to to about V2 inches square. The The beltbeltdrive grinder, however, has has much much more clearance. clearance. Diamond Blades. Blades.—Glass, Glass, hard alloys and gems are commonly cut with the use of a diamond cut-off wheel. This is a metal wheel wheel with with diamond chips impregnated impregnated around around the rim. Ready-made wheels, six inches in diameter, cost about $5. $5. One carat of diamond bort (value about $2) will charge charge the the homehomemade wheel. This is made from a disk of 1/16 1/ 16 inch thick thick steel. steel. Nicks Nicks cut around the wheel receive the bort mixed with vaseline, the chips then being sealed in in place place by by rollrolling with a hardened hardened steel steel roller, roller, as shown in Figs. 2 and 3. 3. DiaDiamond blades are generally run at somewhat lower speeds than other types of cut-off wheels, and must always be run wet. The The grain grain size size for average work should be 5050grit. Cutting-Off Cutting Off on on Lathe. Lathe.—The The lathe performs excellently as a cut-off —

A pan fitted fitted below below the the grindgrindA bread bread pan er holds the the coolant coolant when when wet wet cutcutting ting or or grinding grinding is is to to be be done. done.

sive wheel guard is not available, the regular regular saw saw guard can be fitted with a sheet metal hood to to serve serve the purpose. Any metal cut with a dry wheel will disdiscolor through heat generated by the wheel, but this this surface film is easily reremoved by sanding with fine abrasive paper. paper.

VI6 GROOVE

ROLLER

-1"

A True Wheels Wheels Essential. Essential.—A —

balanced wheel with a clean edge is necessary for good good cutting. cutting. Wheels Wheels out of round will wobble wobble and and cut cut considerconsiderably wider than their own thickness. The The use of a stick type type dresser dresser at at regular regular inintervals will keep the wheel in in good good condicondition. In using a stick dresser on cut-off wheels, do not be afraid afraid to to apply apply considerconsiderable pressure against the wheel. wheel. Wheel Wheel dressing is not a cutting operation, operation, but but aa tearing away of the abrasive grains by pressing against the wheel with an abrasive which is somewhat harder than than the the wheel wheel itself. off wheels Cutting-Off on Grinder. Grinder. — Cut Cut-off Cutting Off on can be used successfully successfully on on the the grinder. grinder. The work must never, however, however, be be worked worked freehand. A simple method of working working is is to turn the center link link of of the the tool tool rest rest upupside down, allowing it to pivot pivot at at the the botbottom. Work can then be clamped clamped to to the the tool tool rest and swung into the wheel, as shown shown in in the lower photo on the previous previous page. page. In In another method of working, working, aa table table with with aa slot to accommodate a sliding block can be fitted to the tool rest or clamped clamped to to the the workbench, as shown on the the previous previous page. page. This provides a guide similar to the miter gage used on the circular saw. A simple simple method of wet cutting is shown shown in in the the photo above, and is quite clean in in operation. operation. The water pan is a bread pan. obtainable -

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Right, making making a a diamond blade. Right, blade. Below, Below, cutcutting-off ting-off on on the the lathe. lathe.

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machine, especially on small work which permits the use of the slide rest rest for for feeding feeding as shown in Fig. 4. Either the slide rest feed can be used or the work table can be advanced by hand, guided by the bar which works in the the slot slot of of the the slide slide rest. rest. A special table can be made made if if desired desired so so that work can be cut at the the top top of of the the blade, blade, much the same as on the circular saw. Wet cutting is more readily done on the lathe than on any other machine. machine. .

CHAPTER TWELVE TWELVE

Miscellaneous ABRADING OPERATIONS used Tumbling.—Tumbling Tumbling. Tumbling is extensively used in industry industryfor forfinishing finishingsmall small metal metal parts. parts. The The process processcan canbe beworked workedsuccessfully successfullyinin the the small small shop, shop,using usingaawooden woodenbarrel barrel driven end ofof the lathe. driven on onthe theoutboard outboard end the lathe. The barrel barrelshould shouldbebemade made from hard maple, The from hard maple, as as shown shown in in Fig. Fig.2, 2,and andmust mustbe besolidly solidly constructed, constructed,especially especiallyififcastings castingsofoffair fairsize size are are to tobe betumbled. tumbled.IfIftumbling tumbling is is done done wet, wet, as is sometimes must sometimes the thecase, case,the thebarrel barrel must also be isishinged be watertight. watertight.One Onesection section hinged to form isis fastened to to a a form aalid. lid.The Thebarrel barrel fastened 15-inch pulley 15-inch diameter diameterhardwood hardwood pulley The The work workis isgenerally generallyprocessed processedthrough through a a cycle cycle of at at least least three threeoperations. operations. The The first operation first is is an anashing ashingor orscouring scouring operation which which removes removes all alltool toolmarks marksand and roughroughness on on the the surface surfaceof ofthe thearticle article and and renrenders ders it it smooth. smooth.The Thesecond secondstage stageisisthe the burnishing operation, burnishingor orsemi-polishing semi-polishing operation, the final final stage stageis isthe thetrue truepolishing polishing while the operation. toto tumble operation.The Thetime timerequired required tumble finish finish runs runsfrom from16 16toto48 48hours hours for The for the the three threeoperations. operations. The first first stage stageof of the theprocess process dedemands mandsthe themost mosttime; time; the the final final polish polishcan canbe be done done in in aa very veryshort short time time providing providingthe thepreprevious abrading abradinghas hasbeen been done done thoroughly. thoroughly.The The abrasive abrasiveused usedis isin in loose grain grain form, form,the the grit grit being beingsomewhat somewhat coarser coarserthan thanused usedinin wheel polishing. polishing. Nos. Nos. 24 to 36 are are used usedfor for roughing; roughing;40 40to to80 80for for semi-polishing; semi-polishing;100 100and and —

Scratch Scratchbrushing brushing atat slaw slaw speed speed proprofinish.AA high speed duces a serrated serrated finish. high speed gives a a satin satin finish. finish.

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Tumbling Tumblingwith with abrasive abrasive grains grains makes makes a good finish finish for formetal metalor orplastic plastic parts. parts. A Acycle cycleof ofthree threeoperations operations is generally generally required. required. 6" 6"FACEPLATE FACEPLATE 0

2° 'PULLEY PULLEY - 1 2°

11 %

La .

TUMBLING TUMBLING BARREL BARREL

2°. IS DIA. WOOD PULLEY

60 R R.P.M. COUNTERCOUNTERSHAFT SHAFT DRIVE

120 120 for for polishing. polishing.The Theexact exactabrasive abrasive varies varies considerably, the work be-beconsiderably,depending dependingupon upon the work ing tumbled. tumbled.The Thebarrel barrel is is loaded loaded between between one-third one-thirdand andtwo-thirds two-thirds full, full, the the work work com com prising load while prising about about60 60percent percentofofthe the load while the the balance balanceis ismade madeup upwith withthe the abrasive abrasive grains grains and andsmall smallpegs pegsofofthe thematerial material being being tumbled. tumbled.Slow Slowspeed speedisisabsolutely absolutelyessenessential and andshould shouldnever never exceed M. A tial exceed 9090 R.R. P.P. M. A suitable suitable drive drivewhich whichdoes doesnot notinterfere interfere with with the is is shown inin Fig. 3. 3. the lathe lathedrive driveproper proper shown Fig. Spun Finish. Finish.—An An attractive attractivefinish finishfor formetal metal work brushing at at work is is obtained obtainedby byscratch scratch brushing slow speed, speed, as as shown shownin inthe thelower lowerphoto. photo. A stick stick coated coated with withcoarse coarseabrasive abrasive grains grains can can also also be be used. used.The Thefinish finishconsists consistsofofa a —

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it

finish is is An engine or spot finish Engine Finish.—An Engine Finish. produced on the drill press by the methods methods shown in Figs. 2, 3, and 4. Fig. 2 shows shows how a dowel stick stick is is capped capped with with an an abraabrasive disk for this purpose. Instead of using an abrasive disk, the tip can be leather and the abrasive bonded with wax wax or or grease grease and and fed to the work. The drill press should should run run about 1200 r.p.m. Solid abrasive sticks can be used, used, but but require requirecareful carefulalignment. alignment. A tiny cup wheel, Fig. 3, makes a ring ring patpattern. Fig. 4 shows a good method method of of work. work. ing the engine finish. A A softwood softwood dowel dowel is is used. A strip of thin, hard brass with a hole through it is located on the drill table immediately below the dowel. dowel. The The work work is is fed with a mixture of abrasive grains and and oil or water, the dowel abrading this into the metal. metal. —

Internal Grinding.

Above, Drawing at at Above, grinding grinding glass glass edges. edges. Drawing right used in in proproright shows shows various methods methods used ducing on on engine engine finish. finish.

series of minute rings spun spun around the work, the depth of the serrations depending upon upon the softness of the metal itself and the grit of the abrasive abrasive used. This abrasive treatment is extensively used as a finish finish for spun aluminum aluminum projects. projects. Glass edges Grinding Glass. Glass.—Glass can be ground to an almost perfect polish with the use of of silisilicon carbide abrasive papers used on the disk sander, as shown in Fig. 1. Standard 9 by 11 inch sheets of wet-or-dry paper can be cut into disks for occasional occasional work of this nature. 120-grit gives a smooth, mat edge, while while 220 to 320-grit brings up a very very good polish. The glass should air cool between between cuts. cuts.

—Small holes can be ground by mounting an abrasive stick in a chuck held in the lathe tailstock, as shown in Fig. 5. The setover tailstock se t s the depth of cut. A small hand grinder can be used for the same job, job, and also for a wide wide variety of other work. work. Other Lathe OperaOperations. tions. — — Other ex-

amples of grinding jobs which can be done on the lathe lathe are are shown in Figs. 7 and 8. Fig. 7 shows a groove being run in on a bushing, using a round edge wheel The same set-up with straight wheel and slide rest feed is used for surfacing cylinders. Fig. 8 shows a flat being worked on the end of a shaft. The lathe does not turn in this instance, but is locked by means of the index pin. pin.

—

Tool Tool post post grinders grinders worked worked on the slide slide rest rest are are used used for for a a wide variety of lathe lathe grinding jobs. grinding jobs.

[ 36 ]]

Drilling Glass.—The Glass.—The drilling drillingof ofglass glassisisan an operation thatmay maybe bedone donewith with ease operation that ease onon the drill drill press, press,although althoughdifficult difficultbyby any any other other method. method.The Thedrill drillemployed employed is is aa piece of brass brass tubing tubingwith withan anoutside outsidediamdiameter equal eter equal to tothe thesize sizeof ofthe thehole holetotobebe drilled. The tubing tubingshould should be drilled. The be slotted slotted with with one cut, using aa very verynarrow narrowsaw. saw.The Thecut cut need not not extend extendmore morethan thanabout about 1/41/4inch inch from from the the end endof ofthe thetube. tube.Similar Similarresults results are effected effected by bynotching notchingthe theend endofofthe the tube tube in two or three threeplaces. places.The Thetube tube not two or isisnot sharpened in sharpened in any anyway way— —ititisissimply simplycut cut square on oror square on the theend, end,and andthen thenslotted slotted notched as mentioned. mentioned.The Theglass glassshould shouldbebe notched as supported onaaperfectly perfectlyflat flat piece wood, supported on piece ofof wood, AA or, better, better,on onaapiece pieceof offelt feltororrubber. rubber. dam of putty puttyisisbuilt builtaround aroundthe theplace place where dam of where the hole is is to to be bedrilled, drilled,orora afelt feltring ring can can be used used for for the thesame samepurpose. purpose.The Thewell well is is fed with with aa mixture mixtureof of80-grit 80-gritsilicon siliconcarbide carbide abrasive grainscombined combinedwith withmachine machine abrasive grains oiloil or turpentine. turpentine. Grinding Keyways. Grinding Keyways.—Keyways Keyways and similar similar work work can can be done done with withsmall smallabrasive abrasive wheels mounted mountedin inthe thedrill drillpress. press.The The best best method of holding holdingand andfeeding feedingthe thework work method of is to employ employthe thelathe latheslide sliderest. rest. This This is is easily fitted fittedto tothe thelathe lathetable tablebybymeans means ofof the same same bolts boltsused usedtotoattach attach it to to the the lathe. lathe.An Anunder underview, view, showing the the slide sliderest restbeing being fitted, fitted, isis shown shownin inFig. Fig.2. 2. Fig. 3 shows the the keyway keyway being cut. cut. A A speed speedof of 5,000 R. P. M. M. should should be be used. Wheel Wheelshapes shapesin in any size, size, abrasive, abrasive,or orgrit grit can be obtained ready can be obtained ready mounted mounted on on shanks shankswhich which can be held held in in the thedrill drill press press chuck. chuck. Surface Surface Grinding. Grinding.—A A 3inch cup wheel wheel worked worked in the drill drill press pressoffers offers one of the the best bestmethods methods of surface grinding. grinding.The The work can be beheld heldby bythe the work can lathe slide slide rest restmounted mounted —

—

Top, drilling drilling glass.Photos Photosabove above Top, glass. and and at at left leftshow showuse use of ofslide slide rest rest in in drill drillpress pressgrinding. grinding.

as already already described describedoror in any suitable suitable jig. jig.The The slide rest rest permits permitsfeedfeeding the the work workto tothe the workheld held wheel, wheel, while work stationary in stationary inaamachinmachinist's vise vise or orsimple simplewood wood sur4, is surfixture, fixture, Fig. Fig. 4, faced by feeding feedingthe the faced by wheel wheel to to the thework. work.FairFairly large large surfaces surfacescan canbe be covered byusing usingaadrill drill covered by press press column columncollar collarand and swinging the the work workbelow below wheel, the wheel, the abrasive same method methodas asdedescribed scribed for forgrinding grinding jointerknives knives(see (seepage page jointer 22). Large Large work workcan canalalso be handled handled by byusing usingaa sanding disk disk in in the themanmanner shown shown in in Fig. Fig. 5. 5. Grinding on Shaper. Shaper. — Sanding and and grinding grindingcan can be done done on on the thewood wood shaper, using shaper, using sanding sanding drums, straightwheels, wheels, drums, straight cup wheels, wheels, and andany any other formof ofgrinding grinding other form stone which which can can be be fitted fitted —

A A cup cup wheel wheel mounted mountedin inthe the drill a awide drillpress presswill willhandle handle wide variety varietyof ofsurfacing surfacingoperations. operations

[ 37 1]

Almost for abrasive work. work. Photos on on this this Almost any any tool tool can can be be adapted adapted for page show the shaper, shaper, band band saw saw and and lathe lathe set set up up for for sanding sanding and and grinding. grinding.

to the spindle. For most work, work, the the speed speed is is excesexcessive and should be reduced to about 5,000 R. R. P. P. M. M. This can be done by belting the shaper pulley to aa pulley fitted to the lower end of the drill drill press press motor, motor, lowering the drill head to suit. suit. Figs. Figs. 11 and and 22 above above show typical set-ups. The operation operation shown shown in in Fig. Fig. 2 requires the use of a wood table to bring the work approximately level with the the top top of of the the cup cup wheel wheel which is being used. Final adjustment adjustment as as well well as as feed is provided by the standard travel of the shaper spindle. spindle. Sanding on Band Saw.—The use of narrow abrasive belts on the band saw provides provides an an excellent excellent method method of sanding edge work. Belts up to 1 inch wide can be used. Guides are provided for some band saws to permit the use of belts, but on on other other saws saws the the worker can improvise simple simple guides. guides. As As far far as as guides are concerned, the belt will work perfectly well without them. Ribbon abrasive belts in all standard widths and grain sizes are obtainable obtainable and and are easily spliced to suit the size of the band band saw. saw. Perfect tracking is assured by the upper tilting wheel of the saw, while the standard band saw adjustment permits tensioning. Lathe.—The use of a sanding disk on Sanding on Lathe.—The the lathe is so well known known as as to to require require little little descripdescription. Where the lathe is not not fitted fitted with with aa sanding sanding table, a table can be made from wood, as shown shown in the drawing at right, and fitted with a pipe shank which can be accommodated in the tool tool rest rest base. base. All operations described in the chapter chapter on on the the disk disk sander can be worked with equal facility facility on on the the lathe with this addition. addition. A A groove groove to to take take the the miter miter gage can be run in on the table table surface surface if if desired. desired. Sanding on Other Tools.—Almost Tools.—Almost

any shop tool can be be used used for for sandsanding and grinding. Sanding disks work perfectly when mounted on the circular saw arbor; small small sandsanding drums are commonly used on the scroll saw; simple jigs jigs can can be be made for the lathe to permit the use of sanding belts. Where the work cannot be taken to the mamachine, a flexible shaft suitable for handling sanding disks disks and and grindgrinding wheels can be used used to to advanadvantage for many operations. operations. [38] [38] %b.

APPENDIX ABRASIVES AND ABRASIVE TERMS Aluminum Aluminum Oxide Oxide ...... An artificial abrasive, abrasive,

Oilstones . . General descriptive term applied to all abrasives when made into stones for bench use. use.

with a base of the natural clay-like mineral, mineral, Bauxite. Color, brown-gray brown-gray to to black; black; in in pure pure Corm, white. Hardness, Hardness, 9.* 9.*

Pumice Used for for final final Pumice .. .. .. A natural abrasive Used polishing, cutting cutting down down finishin4 finishin4 coats coats of of varvarnish, etc. Several grades of fineness. Color, Color, offoffwhite. Hardness, Hardness, 4. 4.

holds Bond Bond. .. . Clay or other substance which holds abrasive grains together together to to form form wheels, wheels, etc. etc.

Crocus . A natural abrasive formed from from oxide oxide of iron. Color, purple. Used for fine polishing. polishing. Hardness, 2. 2.

Quartz abrasive very soft soft.

Emery... A A natural abrasive, being an impure form of crystalline alumina. Much Much softer softer than than aluminum oxide. Color, Color, dull dull black. black. Hardness, Hardness, 8. 8.

Commonly called Flint. Flint. A A natural natural Least expensive of all abrasives abrasives but but Color, yellow. Hardness, Hardness, 6. 6.

Garnet Garnet ..

Roffensfone ... A natural abrasive. Negligible cutting action but good polisher. Color, Color, off-white. off-white. Hardness, 3 Hardness, 3

Glazed .. .. Said of a wheel or stone which Glazed which

Rouge Rouge .. A natural abrasive in in powder powder form. form. Graded fine, very fine, extra fine. fine. Color, Color, red; red; 0. also, green (chromium oxide). Hardness, Hardness, 0.

A natural abrasive mined in the United States. Extensively used in woodworking. Color, red. Hardness, Hardness, 7. 7. has become clogged with with metal metal particles particles so so that it will not not cut. cut.

Silicon Carbide ... An artificial abrasive made by fusing silica sand. Color, Color, gray, gray, green green or or black. Hardness, Hardness, 10. 10.

Grade . The resistance of the bond in a grinding wheel to any force tending to pry the abrasive grains loose. Has nothing to do with with the hardness of the abrasive itself. itself.

Structure abrasive grains grains .. The spacing of abrasive in a grinding wheel. Usually represented by a number from 1 to 12, the the smaller smaller numbers numbers indicatindicating close spacing spacing of of grains. grains.

Grit . . The size of the abrasive grains, determined by the number of of grains grains which, which, end end to to end, equals one one inch. inch.

Lime Lime.... A fine natural abrasive, used exten sively in the final polishing polishing of of brass brass and and nickel. nickel. Color, white. Hardness, Hardness, 1. 1.

Tripoli Tripoli .. A silicious powder consisting of tiny skeletons. Color, pink. Graded. Used in fine polishing. Hardness, Hardness, 5. 5.

*Numbers •Numbersgiven given in this this fable fablelist listthe thehardness hardness of the of the abrasives abrasives in sequence, in sequence, from 10 from (the10 hardest) (the hardest) fo fo 0 (the softest). The number has has no no grading grading value, value, but but is is simply simply used used to to indicate indicate the the hardness hardness of the abrasives in in descending descending order. order.

COATED COATED ABRASIVE ABRASIVESELECTION SELECTION ABRASIVE

MATERIAL

Garnet or Alum. Oxide Garnet Alum. Oxide Alum. Oxide Silicon Carbide Garnet Alum. Oxide A. 0. or Garnet Alum. Oxide Silicon Carbide Garnet Silicon Carbide Alum. Oxide Flint A. 0. or Garnet Alum. Oxide

Hard Woods Woods Soft Woods Aluminum Bakelite Cast Brass Comp. Board Copper Cork Fiber Glass Horn Iron (Cast) (Cast) Ivory Paint (removing) Plastic Steel

ROUGH

FINISH

FINE

21/2-11/2 11/2 11/24 4 40 36-40 36-40 11 1 1/2 /2 -1 1 40-50 3 3 36 50-60 11/2 11/2 24-30 60-80 3-11/2 50-80 24-30

'/2-1/0 1/0 1/0 60-80 60-80 60-80 1/2 1/2 80-100 I 60-80 100-120 100-120 1/2 1/2-1/0 -1/0 60-80 100-120 100-120 1/2 1/2-1/0 -1/0 120-180 120-180 60-80

2/0-3/0 2/0 100 1130 100 100 80-120 1/0 1/0 100-120 100-120 I-0 100 100 120-320 120-320 2/0-3/0 100 100 120-280 120-280 240 2:46 . 100 100

COMPARATIVE GRAINSIZES SIZES COMPARATIVE GRAIN NO. 400 320 280 240 220 180 180

GARNET

10/0 10/0 9/0 8/0 7/0 6/0 5/0

FLINT

... ... ... ... ... ... 4/0 4i0 3/0

EMERY EMERY Fi F 3/0 2/0 1/0 1/0

NO. 150 150 120 120 100 100 80 60 50

GARNET

FLINT

4/0 3/0 2/0 1/0 1/0 W: I

2/0 1/0 1/0 V: 11 11/2 1 1/2 2

1

39 1

EMERY EMERY

NO.

VI 11 11/2 1 1/2 2 Vs 3 3

40 36 30 24 20 16 16

I

GARNET 11/2 1 1/2 2 21/2 2 1/2 3 31/2 4

FLINT 21 /2 2 1/2 3 3

... ... ... ... ... ...

EMERY ... ... .. .. ... ...

... ... ... ...

GRINDING WHEEL WHEEL SELECTION* SELECTION* GRIT GRIT

ABRASIVE ABRASIVE

WORK WORK Aluminum (surfacing) (surfacing) Aluminum Aluminum Aluminum (cutting-off) (cutting-off)'' Brass Brass (surfacing) (surfacing) Brass Brass (cutting-off) (cutting-off) Cast Cast Iron Iron Chisels Chisels (woodworking) (woodworking) Copper Copper(surfacing) (surfacing) Copper Copper(cutting-off) (cutting-off) Cork Cork Cutters Cutters(moulding) (moulding) Drills (sharpening) (sharpening) Glass Glass (grinding) (grinding) Glass (cutting-off) (cutting-off) Glass Glass Glass (cutting-off) (cutting-off) Leather Leather Plastic Plastic Rubber Rubber(hard) (hard) (gumming) Saws (gumming) Steel (soft) Stee, (high (high speed) speed) (cutting-off) Tile (cutting-off) Tubes Tubes (steel) (steel) Welds Welds (smoothing) (smoothing) Wood (hard) (hard)

Alum. Alum. Oxide Oxide (White) (White) Alum. Alum. Oxide Oxide Silicon Carbide Carbide Alum. Oxide Oxide Alum. Silicon Carbide Carbide Alum. Alum. Oxide Oxide Silicon Carbide Carbide Carbide Silicon Carbide Alum. Oxide Oxide (White) (White) Alum. Alum. Alum. Oxide Oxide Alum. Alum. Oxide Oxide (White) (White) Silicon Carbide Carbide(Green) (Green) Silicon Carbide Carbide(Green) (Green) Diamond Diamond Silicon Carbide Carbide Silicon Carbide Carbide Silicon Carbide Carbide Alum. Alum. Oxide Oxide Alum. Alum. Oxide Oxide Alum. Alum. Oxide Oxide (White) (White) Silicor Silicor Carbide Carbide Alum. Alum. Oxide Oxide Alum. Alum. Oxide Oxide Silicon Carbide Carbide

46 29 36 30 46 60 60 36 60 60 60 150 150 90 60 96 60 46 60 60 60 30 60 36 30

GRADE GRADE

BOND Vitrified Vitrified Resinoid Resinoid Vitrified Vitrified Resinoid Resinoid Vitrified Vitrified Vitrified Vitrified Vitrified Vitrified Rubber Rubber Vitrified Vitrified Vitrified Vitrified Vitrified Vitrified Vitrified Vitrified Rubber Rubber Copper Copper Vitrified Vitrified Rubber Rubber Resinoid Resinoid Vitrified Vitrified Vitrified Vitrified Vitrified Vitrified Resinoid Resinoid Rubber Rubber Vitrified Vitrified Vitrified Vitrified

Soft Hard Hard Medium Medium Very Hard Hard Very Soft Medium Medium Medium Medium Hard Hard Soft Medium Medium Medium Medium Hard Hard Hard Hard Medium Medium Soft Medium Medium Medium Medium Medium Medium Medium Medium Soft Hard Hard Hard Hard Hard Hard Soft

** Adapted The Norton Norton Company. Company. Adapted from fables by The

Recommended Recommended

Recommended Recommended

WHEEL WHEEL SPEEDS SPEEDS

BELT and DRUM DRUMSPEEDS SPEEDS BELT and 3 100 s.f.m. abrasivebelts belts 48 inch inch abrasive 2,800 s.f.m 6 to 10-h. 10-h. abrasive abrasivebelts belts 2,900 s.f.m. 10 to to 16-ft. 16-ft. abrasive abrasivebelts.. belts.. 10 9,000s.f.m s.f.m 98 polishing belts belts 9,000 98inch inch polishing 3 inch inch drums drums(coarse (coarsegrit grit abrasive). abrasive). 1,800 1,800 r.p.m r.p.m 2,900 r.p.m. inch drums drums(fine (fine grit abrasive) 2,900 r.p.m. 3 inch grit abrasive) 1,200 r.p.m. 1,200 r.p.m. 1 1 inch inch drums drums (closed (closedcoating) coating) 1,800 r.p.m. 1,800 r.p.m. 1 inch drums drums (open coating) (open coating) 1 inch 1,800 r.p.m. r.p.m. 10 10 to to12 12inch inchabrasive abrasive disks disks 4 500 s.f.m. Abrasive Abrasive disks disks .

Chisel ChiselGrinding Grinding 5,000-6,000 s.f.m . 6,000-8,000 s.f.m Cut-off Cut-offWheels Wheels 9,000-6,000 9,000-6,000 ss f.m. f.m. Surface Surface Grinding Grinding Polishing 6,000-9,000 s.f.m. Polishing Polishing Polishing (soft (soft rubber rubberwheels) wheels) 9,000 s.f.m .. Buffing........ ...... 6,000-9,000 s.f.m. Scratch ScratchBrushing Brushing(rough (rough finish) finish) 600 r.p.m. r.p.m. Scratch finish) 9,000-6,000 s.f.m. ScratchBrushing Brushing(satin (satin finish) 9,000-6,000 s.f.m. GeneralGrinding Grinding...... ...... General 5,000-6,500 s.f.m. Internal 2 000-6,000 s.f.m. InternalGrinding Grinding

GRINDING GRINDING WHEEL WHEELSPEEDS SPEEDS IN IN R. R. P. M. DIAMETER DIAMETER OF OF WHEEL WHEEL 9000 s.f.m. 9500 s.f.m

R P. P. M. M. FOR FORSTATED STATEDSURFACE SURFACESPEED SPEED 5000 s.f.m. 5500 s.f.m. 6000 aim. 6500 s.f.m. 7000 s.f.m. 7500 s.f.m 6000 s.f.m.

1I

15,279 15,279

17,189 17,189

19,098 19,098

21,008

22,918

24,828

26,737

28,647

2

7,639

8,599

9,599

10,509 10,509

11,959 11,959

12,919 12,919

13,368 13,368

14,328 14,328

3

5,093

5,729

6,366

7,003

7,639

8,276

8,913

9,599

4

3,820

4,297

9,775

5,252

5,729

6,207

6,685

7,162

5

3,056

3.438

3,820

4,202

9,589

4,966

5,398

5,730

6

2,546

2,865

3,183

3,501 3,501

3,820

4,138

9,956

4,775

7

2,183

2,455

2,728

3,001 3,001

3,274

3,547

3,820

4,092

8

1,910 1,910

2,148

2,387

2,626

2,865

3, 103

3,392

3,580

10 10

1,528 1,528

1,719 1,719

1,910 1,910

2,101 2,101

2,292

2,983

2,674

2,865

[40] [ 40 ]