Prototyping Integrated Product and Process Design

ME 475 | 2011-2012

Creativity Dilbert Style

Class Logistics

• Peer reviews etc. = 2% points overall• Individual contribution multipliers

• If everybody is working equally, and team gets an A, all members get an A

• All members can’t get A if team grade is B.

• Average must be 1.0 or less; we’ll adjust it if it’s not

• Individual Assignment 2• Evaluate your team’s work on concept generation and evaluation

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Individual Contribution Multipliers

Build and Test Models and Protos

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Perform Economic Analysis

Benchmark Competitive Products

Build and Test Models and Prototypes

IdentifyCustomer

Needs

EstablishTarget

Specifications

GenerateProduct

Concepts

SelectProduct

Concept(s)

Set Final

Specifications

PlanDownstreamDevelopment

TestProduct

Concept(s)

DevelopmentPlan

Things to Think About

• What is a prototype?

• Why do we use them?

• What are the different kinds of prototypes?

• How do we plan for prototypes?

• What resources are available to us for making prototypes?

•Quiz: Closed book

• 1 minute as an individual; then 2 minutes as a team. Team scores will be reported.

1. A prototype is ___________________ of a product along _____________________.

In the text, prototypes are classified along two axes.

2. One axis is from _____________ to _____________________.

3. The other axis is from _________________ to _________________.

6 points possible; one point per blank.

What is a Prototype?

A prototype is an approximation of the part or product along one or more dimensions of interest.

For the creation of the hand-held computing paradigm and the creation of the first commercially successful example of a hand-held computing device.

Types of Prototypes

Note: The text considers math models of a product to be a kind of prototype

A Needle in the Haystack

Why Make Prototypes?

Prototypes are used in product development for:1. Learning (to answer questions or gain experience); “how

does it work”, “what affects its performance”, “does it fit”, “can it withstand the loading conditions”?

2. Communicating an idea or concept3. Integrating components and subsystems to make sure

they work together as expected4. Demonstrating product development milestones (that the

product has reached a desired level of functionality/usability/desired aesthetics)

5. Push the project along – prototypes can be goals that focus efforts

Mechanical Advantage (Moments)

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4

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0 45 90 135 180

Theta 2

M2/

M3

Kinematics Analysis

How do we Know it Works?

Motion Simulations

Finite Element Analyses

Evaluation of Various Prototypes

1 2

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Prototyping Principles to Consider

• Analytical prototypes are more flexible than physical prototypes

• Physical prototypes are required to detect unanticipated phenomena

• Prototypes reduce the risk of costly iterations • Prototypes expedite other development tests

How to Plan a Prototype

A four-step prototype planning process:

1. Define the Purpose of the PrototypeWhat question are we trying to answer?

2. Establish the level of approximation of the prototype

3. Outline an experimental plan

4. Create a schedule for procurement, construction, and testing

Level of Approximation

- Low fidelity model- Low computational cost

- High fidelity model- High computational cost

Simple models can be your friends

• Don’t ignore the benefits of simple approximations

• Reference books have solved models for common cases• Machine design handbooks• Roark’s formulas for stress and strain

• Answers may be good enough to proceed

How to Plan a Prototype

Team Exercise

• Identify three important questions about one of your top concepts

• For each of these questions, identify the following:• an analytical prototype that could be used to

help answer the question• a physical prototype that could be used to help

answer the question

Series of Prototypes

How do we plan for a series of Prototypes?

• A few quick mock-ups to help select final concept• Multiple prototypes (and multiple types of prototypes) to take your work from concept to final design• Milestone prototypes at the end of semester 1.• Final prototype, that shows the full function

of your product/process (at end of semester 2)

POC Hardware:Ink Jet Cartridge De-taper

• Device must remove tape placed over ink cartridge nozzles

De-taper Prototype 1

De-taper Prototype 2

De-taper Prototype 3

De-taper Final Design

Pistachio Feeder

Pistachio Prototypes

Pistachio Prototype

Pistachio Final Design

Pistachio Final Design

Dangers of Prototyping

• “Hardware swamp”

• All the efforts are going in to making the prototype work, rather than working on the design.

• If you can’t readily make it work in the lab as a prototype, the chances it will work in the real world are very small.

• Follow your plan!

What is available to you?

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Physical

Analytical

Ken’s Machine Shop (150 CB)Rapid Prototyping Lab (Perry Carter (422-2901))Composites LabTooling Lab (155 CTB)PRL(SW of smoke stack)

Laser CutterCNC RouterFilm Cutter

Precision Machining Lab (108 CTB)Kevin Cole & Checkout Room

Finite Element AnalysisMotion SimulationTolerance SimulationSolid CAD ModelingGoverning Relationships (previous classes)Technical Computing (matlab, etc)

Resources for POC and Design

• To find ideas for concept generation

• To find out what is on the market for purchase

• To obtain parts for Proof of Concept (POC)

• To order components for final designs

Review

• Reduce risk by proving with multiple avenues that your designs will work

• Physical and analytical prototypes can help

• Have a purpose for a prototype before you make it

• Use a series of prototypes to support your product development efforts

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Rapid Prototyping (RP)

• Layer-by-layer fabrication of 3D physical models from CAD Data. (note that these methods are additive, not subtractive)

• RP Systems join liquid, powder, sheet materials to form complex parts.

• RP Systems fabricate plastic, wood, ceramic, and metal objects.

• “Rapid” means 1 hour to 3-4 days, compared to days or weeks for subtractive approaches.

• Began in 1986 when Stereolithography process was patented.

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Rapid Prototyping Process

1. Create the CAD Model

2. Convert the CAD Model to data exchange format

3. Slice the STL File into thin cross-sectional layers

4. Layer-by-Layer Construction

5. Cleaning and Post-processing

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Stereolithography (SLA)

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SLA Video

• sla.avi

Watch Your Units!

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Fused Deposition Modeling (FDM)

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FDM Video

• fdm.avi

Example - McMaster

Prove, with two different methods, that your designs

will work as expected!!!

He’s Crazy! Why do that?

A Simple Example

Prove that your assembly of 39 parts has the proper interferences and clearances.

Solid CAD Model

Prototype Model

Another Example

Strain Energy Model

Finite Element Model

An Important Connection

Physical Prototype, Mock-Up, Proof of Concept Hardware

Digital prototype, Digital mock-up, Virtual prototype

Predictive math model, physics model

Analytical Prototypes

Digital prototype, Digital mock-up, Virtual prototype