Ramping Up an Alternative Approach to Traditional Architectural Model Building Ranjeet Agarwala Department of Technology Systems East Carolina University, Greenville, NC 27858 Robert A. Chin Department of Technology Systems East Carolina University, Greenville, NC 27858 Jeremy McKee Department of Technology Systems East Carolina University, Greenville, NC 27858

ABSTRACT - An investigation was conducted to

I. Introduction

examine the viability of constructing rapid prototyping-

Architectural and interior design model making

aided architectural models in technology programs.

with the aid of rapid prototyping (RP) technology offers

The subject of the investigation was a single story

substantial advantages over traditional model making.

duplex. Two rapid prototyping technologies were used

The automated process relies on computer programs

to produce the components that made up the

and sophisticated machine movements, which results in

architectural model. The solid based technology was

more

represented by the Stratasys Dimension machine and

opportunities to produce more creative solutions. RP

the powder based technology was represented by the

technology allows the designer to create, modify and

Zprinter 310 plus monochrome printer. The process for

reproduce sophisticated architectural models with

creating the model and comparisons between the two

relative ease in comparison to the traditional model

technologies/machines were analyzed. Technology

making process.

accurate

models,

greater

precision,

and

students can benefit from experiences building models

According to Porter and Neale (2000), in spite of

aided by rapid prototyping technology. Furthermore, it

and because of the digital revolution, model making in

stimulates interest among students exposed to the

architecture and interior design is experiencing

technology and can serve as a mechanism for

resurgence. They note that this is due in great part to

improving design solutions. The difficulty now is

technology’s capacity to take a model and modify,

delivering rapid prototyping instruction to students who

refine, and digitally transform back into a new physical

traditionally do not nor are required to take rapid

model.

prototyping, a traditionally manufacturing oriented course.

Mace (2007) notes that models (a) complement drawings as a communication tool, (b) enable designers to work out and visualize their ideas in 3D before

63rd Annual ASEE/EDGD Mid-Year Conference Proceedings, Berkeley, California – January 4-7, 2009

committing to a design, and (c) enable clients to gain an

Dimensional Objects by Stereolithography issued

instant 3D overview of a building/space and understand

March 11, 1986. With respect to the mechanics of RP,

the design intent. As well, another communication tool,

Savla Associates (2008) notes that in Hull’s invention a

the realist snapshot, can be produced with the addition

concentrated beam of ultraviolet light is focused onto

of lighting.

the surface of a vat filled with liquid photopolymer (see

The production of architectural models using

Figure 2). The light beam, moving under computer

traditional means, however, is a painstaking process.

control, draws each layer of the object onto the surface

Numerous drawbacks to the traditional processes have

of the liquid, and wherever the beam strikes the surface,

been cited. They include but are not limited to poor

the photopolymer polymerizes/crosslinks and changes

quality, human error, high costs, high turnaround times,

to a solid. Software mathematically slices the computer

and the need to possess unique skills. Moreover it is

model of the object into a large number of thin layers.

difficult to make changes in the existing model once the

The process then builds the object layer by layer

model has been built (Gibson, Kvan, and Ming, 2002).

starting with the bottom layer, on an “elevator” that is

RP is an alternative to traditional model making. It

lowered slightly after solidification of each layer.

involves the use of a technology that has traditionally been an integral part of manufacturing endeavors: rapid prototyping or RP. RP,

an

additive

fabrication

technology

(vs

subtractive), exists to build physical models and prototype parts from 3D computer-aided design (CAD) and medical scan data (Wohlers Associates, Inc., 2005). Also

referred

to

as

3D

printing

and

stereolithography, production of the subject matter normally involves (a) the development of a three dimensional model with the aid of a computer, (b)

Figure 1. Steps involved in the RP Process.

converting the file of the three dimensional model to the STL file format, (c) preprocessing, which involves

Porter and Neale (2000) suggest that among the top

up-loading the STL file to the 3D printer and orienting

five skills architectural and interior design employers

the model for efficient and effective production, (d)

seek out is model building.

producing the subject matter, (e) post processing which

graduates are employed by an endeavor that possesses

involves removing the subject matter, cleaning and

the capacity to invest in RP technology or must contract

treating the subject matter. Figure 1 depicts the steps of

RP services, graduates, it seems, should possess a

the RP Process.

working knowledge of RP-aided model building.

Regardless of whether

According to a biography (Wikipedia contributors,

This investigation builds on the work of Kirton and

2008), Charles W. Hull is credited with coining and

Lavoie (2006) and focuses on the practical aspects of

defining the term stereolithography in his U.S. Patent

the process. The problem of this investigation was to

4,575,330, entitled Apparatus for Production of Three-

examine the viability of incorporating architectural and interior design oriented RP-aided model building

63rd Annual ASEE/EDGD Mid-Year Conference Proceedings, Berkeley, California – January 4-7, 2009

experiences in technology programs. A step-by-step

the Stratasys Dimension machine as depicted in Figures

process for creating an architectural model was planned

5 and 6.

and

implemented.

Data

were

collected

and

comparisons made between strategies for reducing production time. Comparisons were also made between two commercially available RP technologies.

Figure 4. Internals of the Z Printer.

Figure 2. Hull’s Stereolithography.

II. Method The powder based RP technology was represented by the Zprinter 310 plus monochrome printer as shown in Figures 3 and 4.

Figure 5. The Stratasys Dimension Machine.

The solid based RP technology was represented by

Figure 3. Powder Based Z Printer.

Figure 6. Internals of the Stratasys Dimension Machine.

63rd Annual ASEE/EDGD Mid-Year Conference Proceedings, Berkeley, California – January 4-7, 2009

Figure 7 depicts the steps involved in constructing the architectural model.

Step Three The scaled AutoCAD model was then exported to Autodesk Inventor as shown in Figure 9. This is a critical step in the process. It contributes to substantial time savings by allowing the user to take advantages of 2-D modeling capabilities of AutoCAD as well as 3-D modeling capabilities of Inventor.

Figure 7. Steps involved in a RP Process.

Step One The first step involved creating a floor plan with the aid of AutoCAD. A single story duplex served as the subject for this investigation. Figure 9. Scaled Floor Plan—Inventor. Step Two The next step involved scaling the floor plan to the finished size of the model for ease of printing (see Figure 8).

Doors and windows were removed for

Step Four Each wall section was subsequently copied to the Inventor sketch plane and extruded. This process was repeated until all wall sections were extruded as shown

modeling.

in Figure 10.

Figure 8. AutoCAD Floor Plan. Figure 10. Extruded sections.

63rd Annual ASEE/EDGD Mid-Year Conference Proceedings, Berkeley, California – January 4-7, 2009

Step Five After all the walls were extruded, the 3-D architectural model was saved as a .STL (stereolithography) file as shown in Figure 11.

Figure 12. Finished parts.

Figure 11. .STL files in the Z-Print Program.

Step Six Figure 13. Architectural model.

The .STL file was subsequently imported to the Powder based RP machine:

the monochrome Z310 III. Analysis

Printer.

Doors are an integral part of an architectural model.

Step Seven The Z-Print program helps users orient and

For the purpose of this investigation, they

served as samples for analysis.

preprocess .STL files to optimize the RP process. Saving the Z-Print file as a template file saves substantial time. It allows the user to duplicate the process again in the future with the same level of accuracy. The user can also e-mail electronic files if the process needs to be replicated by a different user.

Steps Eight and Nine After the preprocessing stage and various system checks were completed, the parts were then printed and

Figure 14. Doors in the architectural model.

post processed (see Figure 12). The post processed parts were then assembled producing the final model. Figure 13 depicts the final model with landscaping.

The doors for the model were built separately as shown in Figure 14. These doors were then glued to the

63rd Annual ASEE/EDGD Mid-Year Conference Proceedings, Berkeley, California – January 4-7, 2009

model.

Ten doors were drawn and preprocessed

Preprocessing took approximately four minutes. If all

separately using the Z-Printer and the Stratasys

the .STL files are saved as a Z-Print template file it will

Dimension machine.

result in a total savings of four minutes or approximately 37%.

Therefore, substantial time

savings can be realized if production of similar parts is required in the future by the same or a different user. Figure 18 depicts time comparisons between the two methods.

Figure 15. Ten doors preprocessed in Z-Print.

The ten doors were then preprocessed using the ZPrinter as shown in Figure 15 and the Stratasys Dimension machine (see Figure 16 and Figure 17).

Figure 17. Ten doors preprocessed.

STL files of the 10 doors were imported in the Catalyst program. Catalyst is a computer program that interfaces with the Stratasys Dimension machine. The software is used for preprocessing .STL files before prototyping. According to the program, one hundred and thirty five minutes was required to prototype the doors using the FDM technique when compared to 11 minutes using the Z-Printer. Figure 19 shows the time comparisons.

Figure 16. Preprocessed door in Stratasys Dimension Machine.

IV. Discussion RP offers an effective means for building architectural models directly from computer-aided

The Z-print template file was saved for further duplication. It was observed from the Z-Print program that the total time taken to preprocess and prototype the ten

design models. These models can be developed using any computer-aided design application. Furthermore, RP technology provides an edge over traditional methods in architectural model building.

doors using the Z-printer was about eleven minutes.

63rd Annual ASEE/EDGD Mid-Year Conference Proceedings, Berkeley, California – January 4-7, 2009

models using the Stratasys Dimension machine due to large cycle times. Using AutoCAD and Inventor in the process of model building contributes to substantial time savings by allowing the user to take advantages of 2-D modeling capabilities of AutoCAD as well as 3-D modeling capabilities of Inventor. Creating and saving Z-Print files as template files can further reduce time as the entire process can be automated. The user can also e-mail electronic Z-Print template files if the process needs to be replicated by different users. Figure 18. Time comparison. V. References It was observed from the results that RP offers substantial advantages over traditional model process in architectural model building. The process is automated compared to traditional methods as it relies on computer

programs

and

sophisticated

machine

movements leading to more accuracy and precision. This allows designers to create, modify and reproduce

Gibson, I., Kvan, T., & Ming, L. W. (2002). Rapid prototyping for architectural models. Retrieved October 16, 2008, from http://www.emeraldinsight.com/ Insight/ViewContentServlet;jsessionid=3E40DBA02B6 182918EB973BF6C41F6C0?Filename=Published/Eme raldFullTextArticle/Articles/1560080204.html Kirton, E. F. & Lavoie, S. D. (2006). Utilizing Rapid prototyping for architectural modeling. Engineering Design Graphics Journal, 70(1), 23-28.

sophisticated architectural models with relative ease. Materialgeeza. (2008). Stereolithograthy apparatus schematic. Retrieved October 16, 2008, from http://en.wikipedia.org/wiki/Image:Stereolithography_a pparatus.jpg#file Mace, V. (2007). Model making. Retrieved October 17, 2008, from http://www.design-skills.org/ model_making.html Porter, T., & Neale, J. (2000). Architectural supermodels. Burlington, MA: Architectural Press. (http://books.google.com/books/elsevier?id=3XALYq MtyjAC&dq=Architectural+supermodels&source=gbs_ summary_s&cad=0) Savla Associates. (2008). Stereolithography. Retrieved October 16, 2008, from http://www.photopolymer.com/ stereolithography.htm Figure 19. Time comparisons.

It was also observed that architectural models can be duplicated and mass produced with the same degree of precision using the RP process.

As observed in

Figure 19, it is difficult to prototype large architectural

Wohlers Associates, Inc. (2005). What is rapid prototyping? Retrieved October 16, 2008, from http://wohlersassociates.com/rapid-prototyping.html Wikipedia contributors. (2008, 29 March). Chuck Hull. Retrieved October 16, 2008, from http://en.wikipedia.org/wiki/Chuck_Hull

63rd Annual ASEE/EDGD Mid-Year Conference Proceedings, Berkeley, California – January 4-7, 2009