Subtractive Manufacturing Exercise #1 Step #2 Key Fob Project Using Velocity CNC Software for the CNC Milling Machine

Note: In order to use this set of instructions to produce the required part, you must have completed the assigned CAD drawing (Step #1), had the drawing approved and produced a DXF file of that drawing.

Open the Velocity CNC software. At the prompt, select “Don’t Connect”.

Note: The only time that you should select “Connect” is when you are actually preparing to use the CNC milling machine to produce a part.

Verify that the correct setup and tooling is in place for producing the G-code program for the CNC Milling Machine. Look at the information located at the top left hand side of the screen. Be sure it reads “D&MMILL-V4.stp – Velocity.tlg”. If the setup or tooling needs to be changed see the instructor.

Select “Import DXF” from the “File” menu to import your DXF file.

Note: Do not select “Open G-code” ,“Open Setup” or “Open Tooling” !

Your DXF file should be identified as a DXF file in your folder.

The Velocity software will be searching for a DXF file . Select the appropriate DXF file and open it.

As soon as you select your DXF file, a prompt box will appear asking you to save your completed work as a “G-code” file (.CNC). Save your work as the DXF file name and add the number “1” (this is to indicate the 1st set of G-code data that will be created for this project). The Velocity CNC software will now be changing the DXF data into G-code data.

Note: The original name of the program was “keyfob 4515”. The new name is” keyfob 4515 1”.

The “Configuration” screen appears next. The next few slides will guide you through the process of configuring the software to write the “G-code” program.

Set the configuration for the G-code program by making the data in the shaded areas match the data shown in the large highlighted boxes. Some items will need changing, others will not.

Set the “Z Axis Coordinates”.

Set the “Feedrates”.

Set the “Start of File” additional codes.

Set the “End of File” additional codes.

When finished with the additional code, select “OK”.

G00 Z.5 G00 X0 Y0 M05

When the data in the Configuration Table has been set, select “OK”.

When the configuration process is completed, a screen will appear with both an isometric and top view “wire frame” diagram of your design. Below the diagrams and to the left will be the newly produced G-code program.

Isometric view

Top view

G-code program

In the lower right hand side of the screen, change the “Program Feed-rate” to “9999” to make the emulation run as quickly as possible. Then select “Start” to watch the emulation of your program.

As the emulation runs, dotted blue lines will appear for all G00 commands. Solid blue lines will appear for all G01, G02 & G03 commands. For this part of this project you will want eliminate all G-code instructions that are not associated with the letters from the drawing.

Stop the emulation from running when you recognize a “tool path” that does not need to be cut (ones that are not associated with the letters). Press any key on the keyboard to make the emulation stop. Recognize the line number in the program where the emulation stopped. To remove unwanted lines of code, double click in the G-code program area to open the “Code Editor”.

Find the same line number in the “Code Editor” where the emulation had stopped the program. Identify the specific lines of code near that line number that will need to be removed. Highlight the lines of code that are to be removed and hit the delete key on the keyboard. Select “Update Toolpath” and the “Close” the editor. Upon exiting, you will be prompted to save the file. Select “Yes” – you want to update this CNC file.

Leave these last lines of code in place

Reset the “Program Coordinates” by selecting “Set” and “Zero All”. Reset the G-code program by selecting “Reset”. Run another emulation to see if your program cuts only the tool paths for the letters.

If the emulation still shows toolpaths being cut that should not be, repeat the editing process until all issues are resolved. If you have removed too many lines of code or if there are multiple issues with the program, start again from the beginning by importing the DXF file again. If you believe the program to be correct, show me the emulation.

There is no need to save the program at this point! The program has already been saved!

Do not select:

“Save “Save “Save “Save

Setup” Setup As” Tooling” or Tooling As”

Exit from the program and follow the instructions for cutting out the part on the CNC milling machine. This first part is simply a “test” part to allow you to practice setting up the milling machine for cutting.