This paper presents the evolution of an experimental .courseat Cal Poly which
applies rapid prototyping techniques, enabling a concurrent engineering approach
to product development. This is applied within our manufacturillgenvironmentof
foundry and machining processes. It focuses upon the.mainprobletnof rapid
tooling for these processes. A contemporary problenlprovided by industry is used
as the vehicle for illustrating rapidprototyping techniques within a concurrent
engineering context.Mechanical Engineerin

Koch, Martin

Menon, Unny

English

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Rapid Prototyping for Foundry Tool Making:Curriculum and Industrial ProjectsUnny Menon and Martin KochIndustrial Engineering DepartmentCalifornia Polytechnic State UniversitySan Luis Obispo, CA 93407AbstractThis paper presents the evolution of an experimental .courseat Cal Poly whichapplies rapid prototyping techniques, enabling a concurrent engineering approachto product development. This is applied within our manufacturillgenvironmentoffoundry and machining processes. It focuses upon the.mainprobletnof rapidtooling for these processes. A contemporary problenlprovided by industry is usedas the vehicle for illustrating rapidprototyping techniques within a concurrentengineering context.IntroductionCal Poly has a strong tradition of "hands...on" approaches to undergraduateengineering.education.All.engineeringprograms require s~bstantiallab ••experiencesto convey the applications oftheory. Thecurriculuma<:tdressesboththeDe~ignandManufacturing Processes, in the traditional manner as. functionally independentareas. The problem then becomes of how to engenderal1illt~gr~tiveperspectiveproblem is to evolve an integrativecours~'i\Vhich]lti1izes rapid\prototyping as anenabling technology, fora concurrent\ engineering based analysis. ofmanufacturability issues within a specific product development.The course seeks to consolidate the three 111ajorareas of:concllrrentThe experimental course utilizes a product developmellt/manufacturing. processproblem (the case.study) from an industrial sponsor. This provides a .sound basisfor the application of rapid prototyping techniques.95Experimental Course StructureThe course format is a combination of seminar presentations and team-basedlab activities. The seminars occur on a weekly basis and the lab work scheduledby the teams as needed. The presenters are typically industrial representatives whothen help lead the discussions. The students prepare for the seminars bycompleting both readings assignments and, where appropriate, labThe goal of the seminar portion of the course is to impart an understandingof the sequence of the product development cycle from conceptualization throughprocess design and manufacturing implementation. This within themanufacturing environment of foundry related processes. Secondly, we hope toimpart an understanding of the application of concurrent and rapidprototyping to this complete sequence. The subjects of the presenters are chosento build towards this understanding. We began first with an overview ourmanufacturing environment and its inherent problems; specifically "toolingbottleneck." We then introduce concurrent engineering ideals and structures andshow how rapid prototyping can provide a set of "enabling technologies" useful formitigating this "bottleneck." Next we focus on our first case study which showsa traditional approach to a product's development. We then concentrate uponsecond case study "The Industrial Problem" which is used as the frameworkan in-depth study of the possibilities of the linked applicationsengineering and rapid prototyping.The goal of the lab portion of the course is to provide the students with theexperience of participating in a multiple team project within aenabled concurrent engineering environment. Each of theassigned a focussed task/problem area to address: project management, ......"""~"AJiii.JJ~,A.manufacturing. The overall task within the framework of this two hourcourse was for the teams to build a joint overview of the processes, the problemsand the possibilities. This sometimes required solely conceptual such asunderstanding the role of laser scanning for digitizing hand produced artistic solemodel into cad systems. And, sometimes the task required hands-on lab work suchas using RTV silicone to replicate prototypes into foundry core-sand forcasting operations. The framework provides an interesting blend of esoterictheories and dirty manufacturing processes. Without the Industrial Problem itwould have been difficult to provide a focus for linking together all the differentareas, subjects, and processes that were investigated.96r"'lIlot()r productionstudents to obtain insightsand assembly of a product.lI-"-'''-'~LJl.Jl.JI.'''' necessary for the moldsubsequent post...the Manufacturingand clubs withinAAAAIIJA""'.IlAA""'AA"''''''''' the· castingbe delivered backis what is reviewed in thisinter...dependenceVVJLll"",,,,,JL A ""'JLA'" engineering •learning............... lI-Jl. .....JI. Jl.JI................,...".JI."'"v••'" coursesCase Study 2 : NIKE Midsole MoldThis case study was the main focus of the course. The lessons fromthe Airwe feel is central t%urfollndrylmanllfacturing process. It is the need to be ableto •••. rapidlyandeconomica.llyproduce tooling for both prototyping •. and productionneeds ..• Witbthe NIKE Midsole Mold the problem addressed is how to start witha bandmade artistic prototype a,ndto then quickly produce molds for the productionoftbe polyurethane midsoles .in a range of sizes. At first thismigbt not appear tobea foundry tooling. problem but it can be seen as such in that tbere is a parallelbetween the needs of both industries for sets of working molds. Eurthermore thereneeds to be an easily executed process for mold design modification between thedesign and manufacturing teams. In both industries tbe main production problemis tbe "tooling bottleneck." In addition since the foundry processes can be used tomake the sole molds themselves there is a tight linkage of possibilities.The lab project task then becomes that of how to apply rapidprototypingandconcurrent engineering techniques to this mold production problem. do sorequires a full understanding of the different possible avenues of production. Toaccomplish this the three team structure was devised. A project management teamwould supervise the interaction of a design· team and a manufacturing team. Thedesign team would produce the prototypes from which the manufacturing teamwould produce production molds. At first the main interface between the designand the manufacturing teatnS was seen to be the deliverable of apbysical masterpositive of the midsole to be produced. This was later expanded to allow thedesign team to produce the prototypes ofthe tooling. as specified by manufacturing.The missions of teams were:Project Management Team:To provide coordination, administrative and team communication services;to facilitate progress towards analysis and solution of the· case·study. The key roleof this team was to engender and enable the concurrent engineering philosophy.Design/Prototyping Team:The focus of this team was to provide the CAD/CAM services for theproject. Their key tasks were to 1) Capmre the original design concept into CAD,2) Manipulate within CAD for both design modification and the "grading process ttneeded to produce that design in the different shoe sizes, and 3) Prototype out of98CAD of the physical units needed for the. interface to the manufacturing team.For each task a set of options were investigated.the Capture task three methods were investigated: 1) Non-contact designcapture methods of scanning and.·Industrial Computed Tomography, 2)Contact design capture based onCMMuseand3) TraditionaLcapture based uponmicrometers, radius gauges etc. for manual entry into the CAD systems.the Manipulate task different systems were compared including.Cadkey,CadCam, Pro/Engineer covering traditional constructive solid model methods. andparametric based•options, and FEA analysis.the Prototyping task the methods investigated included Stereo-Lithography, Selective Laser Sintering, traditionalCNC machining of both metalmolds and investment castable machinable waxes and the growing set of other rapidprototyping technologies.Manufacturing Team:task of this team was to translate the deliverables from theDesign/Prototyping Team into production tooling. This requires interaction withthe .design team to··continqallyredennethe· deliverables setandtoexplorethe rangeofproduction method > possibilities. The processes investigated by ·this team wereextensive· and included the·· direct investment .casting of prototypes; the direct .useprototypes wax injection .molds; the. replication from prototypes ·forinjection molds, spray-metal based molds, foundry cores for thedirect casting of molds; and plastic foundry tooling production. Some ·of theseprocesses only studied, others. were· tested.The three teams worked well together and a wellthe problem was achieved. Thefocus teams and theirtendency for99Figure 2 shows tbeprocess where a prototype (in this case an actual midsole)was used to make an RTV Silicone mold (via the Ciba-Geigy method) which wasthen used to produce a replicate of the prototype in foundry core-sand material(either epoxy or shell binder .systems). This core can then be used with bothspray-metal and traditional aluminum casting processes to produce metal molds forsubsequent polyurethane midsole production.ConclusionsAn experimental course has been offered which applies rapid prototypingtechnologies•and concurrent engineering structures to foundry based manufacturingproblem.s. The format is a combination of seminar presentations by industrialrepresentatives and "hands-on" lab activities by teams addressing different aspectsof a product development problem described by industry, in this case: the NIKECorporation. The focusing upon a case study problem with the· realm of a specificset of manufacturing processes is seen to be the key for studying the wide varietyof subjects which are related to rapid prototyping.100AcknowledgementsWe would like to thank the NIKE Corporation for their generous donationof time and materials, particularly Tom Paine,DaveVattes and Bruce Kilgore fortheirpersonal efforts. We would also.like to thank the following presenters whodid so much to help make the course· current and >full: Tom Cobett (WestCast),(Plynetics) ,•.• Joe .. Beaman•••(UT, Austin)., Reza•.•••••Pouraghabagher ••XIE), Joh11 .••Barnes(PCC Foundry),.and our graduate •students\whose great work and enthusiasm·madethe course the sucess it was; Nick$weeney(CAD/CAM team), Stan Lewis(Manufacturing team) and Andrew Okhuysen (Project Management).Finally .w.e would like to greatly thank the author, patternmaker andfoundryman Ed Hamilton·whose never ending· willingness to help students has beenpart of the inspiration. for this course.101

Rapid Prototype for Foundry Tool Making: Curriculum and Industrial Projects

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Rapid Prototype for Foundry Tool Making: Curriculum and Industrial Projects

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