Reverse Engineering and

Rapid Prototyping

Automated System

Laser

Lathe

Mill

Research Paper

Robot

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By: Scott Frazier, Shaun Eiler, Kyle Wanke, Randy Howerton

Spring 2004

ITDPT 303 Manufacturing Systems

Undergraduate Students, Ball State University

Contents

Introduction   Objectives   Reverse Engineering   Rapid Prototyping   Integrating into Curriculum   Processes   3D Laser Scanning   CyDir Software   FDM   3D Studio Max   Uses RE   Uses RP   Biomedical   Conclusion   References

Introduction

    This rotation in manufacturing systems demonstrated how to make a model from an existing object or 3D computer animated drawing (CAD).  The process is also used by many businesses to make a working model of an object in a short amount of time.  Several applications were used throughout this process including:  3D laser scanner, 3D Studio Max, and fused deposition modeler (FDM).  This paper will discuss the process as well as give as brief overview of  reverse engineering and rapid prototyping including the integration into a technology curriculum.  

Objectives

        The objective of this project was to scan an animal bone using the 3D laser scanner, digitally manipulate the scanned object with CyDir and 3D Studio Max software, and recreate the object using the FDM.

Figure 1 (Wanke, 2004)

Reverse Engineering

    According to Tech Target (n.d.) "Reverse engineering is taking apart an object to see how it works in order to duplicate or enhance the object."  Although these are the main uses reverse engineering it has a wide variety of other uses.   The information gained from this process allows companies to learn how the item works, how it was designed, to create dimensions if no plans currently exist to, and make improvements upon the existing model (Samuelson Law, n.d., & TechTarget, n.d.).  There are several different types of reverse engineering. Listed below are a few examples:

    The first example is taken from automobile manufactures that buy a competitors product to break it down to gain an understanding in an area they may be inferior in (TechTarget, n.d.).  This will help to make their company more competitive in the market.  This is one of the first examples of reverse engineering.

    A second type of reverse engineering deals with computer software and retrieving its code.  To accomplish this the binary code of a program is changed or reversed back into the the source code (TechTarget, n.d.).  Binary code is a computer language that used 0s and 1s that instructs the computer what to do and when to do it.  Source code is a program code that the programmer uses to actually write the program and then it is transformed into binary code (Samuelson Law, n.d.).  This is typically done to alter the software after it has been put into use because the source code has been lost.  Some typical reasons this needs to be done are to adjust glitches, eliminate viruses, and change the software so it can be used on a different type of hardware (Samuelson Law, n.d., & TechTarget, n.d.).  However, there are copyright issues and issues of legality to be taken into consulted before this is process takes place.

    A third type of reverse engineering is recreating an object where the blue prints and/or design specifications were lost or do not exist (Samuelson Law, n.d.).  The object is scanned on a 3D laser scanner which transforms the object to a digital wire image.  From this dimensions can be made as well as object being manipulated in size and orientation.  Also from this digital information a working model can be made using various techniques.  To see an overview of how QC Inspection Services accomplishes this visit www.qcinspect.com/rev.htm  

There are four different stages of reverse engineering that muse be followed: 

  Rapid Prototyping

    According to William Palm "... rapid prototyping refers to a class of technologies that can automatically construct physical models from Computer-Aided Design (CAD) data."  Essentially these models are made by "three dimensional printers" in a short amount of time (Palm, 1998).  This different from the old traditional method because builds and adds material where as CNC tooling removes material to create the final product (Wohlers Associates, 2001).  These models are generally made to communicate ideas and for design testing, but can be used for a variety of things with very few limitations.  Before prototyping models could take weeks or even months depending on the the complexity of the model (Palm, 1998).  With rapid prototyping (RP) these models typically take from three to seventy-two hours.  Wohlers Associates say "When used correctly RP can save impressive amounts of time and money." (Wohlers Associates, 2001)  There are six main rapid prototypes techniques used commercially today.  They are stereolithography, laminated object manufacturing, selective laser sintering, fused deposition modeling, and solid ground curing (Palm, 1998).  Each rapid prototyping process is patented by its own individual company.  Even though they are all unique in their own way, they all follow the same fundamental steps.  These steps are as follows:

1. "Create a CAD model of the design
2. Convert the CAD model to STL format
3. Slice the STL file into thin cross-sectional layers
4. Construct the model one layer atop another
5. Clean and finish the model" (Palm, 1998)

    Rapid Prototyping can help a company become more competitive in today's rapidly advancing market.

Integrating Rapid Prototyping into the Curriculum

    There are several projects that can be used to integrate rapid prototyping into the curriculum that relate to real world experiences.  Illinois State University has several classes with a variety of projects in which they try to accomplish this goal (Brown, R. & Stier, K (2000-2001)).  In their lower classes they start with the basics including CAD drawing and designing, transforming to STL and SML files and slicing.  There higher classes are much more involved and relate more to real life experiences.  The first project they are assigned groups and told they work for a company interested in purchasing rapid prototyping equipment. The students research the different types and decide which would be best for the specific target company.  The next project they actually get to work for a company submitting proposals and making actual parts.  These are some ways to teach the students while reinforcing the fact that this topic really does apply to the real world.     

Processes

    The processes used for operating the 3D laser scanner and FDM machine can be found at the following sites:

• 3D Laser Scanner

• Fused Deposition Modeler

3D Laser Scanning

    The  3D laser scanner used to scan the bone is made by Cyberware model 15.  This is a desktop model made for scanning small objects.  For more information on the scanner visit Cyberware.  To completely recreate the bone digitally it was scanned in to positions each consisting of twelve scans. 

Figure 2 (Wanke, 2004)

Figure 3: Bone is Position 1.  (Wanke, 2004)

CyDir Software

    CyDir software was use to manipulate and combine the scan sets to create the 3D digital wire image.  Below is some views of the software used.

Figure 4:  Program Controls

Figure 5: Mesh view                      

Fuse Deposition Modeler

    The Fused Deposition Modeler used is made by Stratasys Inc.  To view and learn more about Stratasys visit their website.  In fused deposition modeling heated thermoplastic is extruded in strands from the nozzle (Palm, 1998).  The thermoplastic hardens quickly due to the temperature of the platform.  The nozzles move along the x and y planes while the platform moves on the z plane.  Through cross sections the model is created.  Also a support material is extruded from another nozzle which fill in any gaps in the piece to help support it during construction.  After completion the support material is removed and discarded.

Figure 6: The FDM machine and control located at the top.  (Wanke, 2004)

Figure 7:  Completed bone located in the left hand corner of the foreground.  (Wanke, 2004)

Figure 8: Center background original bone, left foreground constructed bone with support material, right foreground constructed bone.  (Wanke, 2004)

3D Studio Max

    3D Studio Max was used to take the completed bone and digitally transform the bone.  This included changing the texture of the bone, placing it in different background, and creating animation with the bone.

Figure 9: Bone imported into 3D Studio Max

Figure 10:  Bone around Ball State Campus.  (Wanke, 2004)

Animation

Uses Reverse Engineering

• Checking for copyright or patent violation

• Checking specification of an order product

• Competing with competitors

• Gain an Understanding of how a product work and functions

• Making item compatible

• Redesigning old technology

(Samuelson Law, n.d., & Intectus Incorporated, 2002)

Uses of Rapid Prototyping

• Creating prototypes or working designs

• Creating a model of an actual product

• Rapid Tooling; automated production of machine tools

• Rapid Manufacturing; creating products that can be sold

• Biomedical

• Very little limitations on what cannot be accomplished

Biomedical

    In this rotation an animal bone was reproduced and in the real world rapid prototyping is being used for biomedical applications.  "On February 23rd, 1994 the first scaffold of a human chromosome was manufactured at the Production Engineering department of SINTEF." (Dolenc, Engelhardt, et al., n.d.)  These are used to examine the human make to possible help to aid in understanding and curing viruses as well as many other medical issues such as aid in reconstruction.  For more information visit Manufacturing Chromosomes and Viruses. 

Conclusion

    Rapid engineering and rapid prototyping are very useful and practical tools that have a large variety of uses.  It can save time and money as well recreating blueprints and design that do not exist.  These techniques have revolutionized model building and presenting of new ideas.  In this rotation this was mimicked this process on a much smaller scale.  An animal bone was scanned, digitally captured, and manipulated as a 3D image, and recreated as a working model using the FDM.

References

Brown, R. & Stier, K (2000-2001). Integrating Rapid Prototyping
     Technology into the Curiculum. Journal of Industrial Technology,
     11(1), 2-6.

Dolenc, A., Engelhardt, P., et al. (n.d.).  Manufacturing Chromosones
     and Viruses:  A New Application Area for RPT. Retrieved April
     20, 2004 from ,  Web site:
     http://www.cs.hut.fi/~ado/chromosome/chromosome.html

Palm, W. (1998).  Rapid Prototyping. Retrieved April
     20, 2004 from ,  Web site:
     http://www.me.psu.edu/lamancusa/rapidpro/primer/chapter2.htm 
 

Wohlers Associates (2001).  What is Rapid Prototyping. Retrieved
     April 14, 2004 from ,  Web site:
     http://wohlersassociates.com/rp.html

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