ME 290P -- October 2002 Rapid Prototyping and its Role in Product Development Carlo H. Séquin EECS Computer Science Division University of California,

CHSCHSUCBUCB ME 290P -- October 2002ME 290P -- October 2002

Rapid Prototyping and its Role in

Product Development

Carlo H. Séquin

EECS Computer Science Division

University of California, Berkeley

CHSCHSUCBUCB Design is an Iterative ProcessDesign is an Iterative Process

Formal Specifications

Detailed Description

Clear Concept

1st `hack'

Demo Prototype

Usable Evaluation Series

Marketable Systems Product

Vague ideaRevision of

artifact

Experiments,

get feedback

CHSCHSUCBUCB A Specific ChallengeA Specific Challenge

Create as soon as possible a 3D "free-form" part

(not a box-like thing that can be built from flat plates)

for evaluation in its application context.

This includes:

visualization

tactile feedback

function verification

simulation of final use.

CHSCHSUCBUCB Conceptual PrototypingConceptual Prototyping

The Traditional Options:

Model from clay

Carve from wood

Bend wire meshing

Carve from styrofoam – perhaps with surface reinforcement

Mill from a block of plastic or aluminum (3- or 4-axes machines)

CHSCHSUCBUCB New Ways of Rapid PrototypingNew Ways of Rapid Prototyping

Based on Layered Manufacturing:

Build the part in a layered fashion-- typically from bottom up.

Conceptually, like stacking many tailored pieces of cardboard on top of one another.

Part geometry needs to be sliced, and the geometry of each slice determined.

Computer controlled, fully automated.

CHSCHSUCBUCB What SFF exists in COE ?What SFF exists in COE ?

In Etcheverry:

A Fused Deposition Modeling Machine

A Z-Corp Color/Mono 3D Printer

In Cory Hall:

Solid Printing / Imaging (3D Systems)

Stereolithography (3D Systems)

You need to prepare:

A “watertight” boundary representation with less than 100’000 triangles

In .STL format.

CHSCHSUCBUCB SFF: Fused Deposition ModelingSFF: Fused Deposition Modeling

Principle:

Beads of semi-liquid ABS* plastic get deposited by a head moving in x-y-plane.

Supports are built from a separate nozzle.

Schematic view ==>

Key player: Stratasys: http://www.stratasys.com/

* acrylonitrile-butadine-styrene

CHSCHSUCBUCB Fused Deposition ModelingFused Deposition Modeling

CHSCHSUCBUCB Looking into the FDM MachineLooking into the FDM Machine

CHSCHSUCBUCB Layered Fabrication of Klein BottleLayered Fabrication of Klein Bottle

Support material

CHSCHSUCBUCB Klein Bottle Skeleton (FDM)Klein Bottle Skeleton (FDM)

CHSCHSUCBUCB Fused Deposition Modeling (FDM)Fused Deposition Modeling (FDM)

An Informal Evaluation Easy to use

Rugged and robust

Could have this in your office

Good transparent software (Quickslice)with multiple entry points: STL, SSL, SML

Inexpensive to operate

Slow

Think about support removal !

CHSCHSUCBUCB What Can Go Wrong ?What Can Go Wrong ?

Black blobs

Toppled supports

CHSCHSUCBUCB SFF: Solid ImagingSFF: Solid Imaging

Droplets of a thermoplastic material are sprayed from a moving print head onto a platform surface.

Need to build a support structures where there are overhangs / bridges.

These supports (of the same material) are given porous, fractal nature.

They need to be removed (manually).

Key player: 3D Systems: http://www.3dsystems.com/index_nav.asp


Supports made from same material, but with a fractal structure


Thermojet Printer (3D Systems)

Technology: Multi-Jet Modeling (MJM)

Resolution (x,y,z): 300 x 400 x 600 DPI

Maximum Model Size: 10 x 7.5 x 8 in (13 lb)

Material: neutral, gray, black thermoplastic: ThermoJet 88: smooth surfaces for casting

ThermoJet 2000: more durable for handling


That’s how partsemerge from theThermojet printer

After partial removalof the supportingscaffolding

CHSCHSUCBUCB 9-Story Intertwined Double Toroid9-Story Intertwined Double Toroid

Bronzeinvestment casting from wax original made on 3D Systems’“Thermojet”


An Informal Evaluation Fast

Inexpensive

Reliable, robust

Good for investment casting

Support removal takes some care(refrigerate model beforehand)

Thermojet 88 parts are fragile

CHSCHSUCBUCB Powder-based ApproachesPowder-based Approaches

Key Properties:

Needs no supports that must be removed!

Uniform bed of powder acts as support.

This powder gets selectively (locally) glued (or fused) together to create the solid portions of the desired part.

CHSCHSUCBUCB SFF: 3D Printing -- PrincipleSFF: 3D Printing -- Principle

Selectively deposit binder droplets onto a bed of powder to form locally solid parts.

Powder Spreading Printing

Build

Feeder

Powder

Head

CHSCHSUCBUCB 3D Printing: Some Key Players3D Printing: Some Key Players

Z Corporation: http://www.zcorp.com/Plaster and starch powders for visualization models.

Soligen: http://www.zcorp.com/Metal and ceramic powdersfor operational prototypes.

CHSCHSUCBUCB 3D Printing:3D Printing: Z CorporationZ Corporation

The Z402 3D Printer Speed: 1-2 vertical inches per hour

Build Volume: 8" x 10" x 8"

Thickness: 3 to 10 mils, selectable



Digging out

CHSCHSUCBUCB Optional Curing: 30 min. @ 200ºF Optional Curing: 30 min. @ 200ºF

Keep some powder in place

<-- Tray for transport


Cleaning up in the de-powdering station


The finished part

Zcorp,

6” diam.,

6hrs.

CHSCHSUCBUCB 120 Cell -- Close-up120 Cell -- Close-up

CHSCHSUCBUCB 3D 3D ColorColor Printing: Z-Corporation Printing: Z-Corporation

The Z402C 3D Color Printer

Differences compared to mono-color printer: Color print head with: Cyan, Yellow, Magenta,

Black, and Neutral.

Smaller build area.

Specs: Speed: 0.33 - 0.66 vertical inches per hour

Build Volume: 6" x 6" x 6"

Thickness: 3 to 10 mils, selectable

Color depth: 80 mils

CHSCHSUCBUCB 3D Color Printing: Z Corporation3D Color Printing: Z Corporation

Use compressed air to blow out central hollow space.

CHSCHSUCBUCB 3D Color Printing: Z Corporation3D Color Printing: Z Corporation

Infiltrate Alkyl Cyanoacrylane Ester = “super-glue” to harden parts and to intensify colors.

CHSCHSUCBUCB What Can Go Wrong ?What Can Go Wrong ?

Blocked glue lines

Crumbling parts

CHSCHSUCBUCB Broken PartsBroken Parts

CHSCHSUCBUCB 3D Printing: Z Corporation3D Printing: Z Corporation

An Informal Evaluation

Fast !

Running expenses: moderate,(but overpriced powder)

Color print head and tubes need some care in maintenance.

Somewhat messy cleanup !

Lot’s of dust everywhere ...

CHSCHSUCBUCB SFF: Stereolithography (SLA)SFF: Stereolithography (SLA)

UV laser beam solidifies the top layerof a photosensitive liquid.

Build Stage

UV Laser Beam

Photopolymer

CHSCHSUCBUCB SFF: Stereolithography (SLA)SFF: Stereolithography (SLA)

SLA Machine by 3D Systems

Maximum build envelope: 350 x 350 x 400 mm in XYZ

Vertical resolution: 0.00177 mm

Position repeatability: ±0.005 mm

Maximum part weight: 56.8 kg

CHSCHSUCBUCB StereolithographyStereolithography

An Informal Evaluation

Can do intricate shapes with small holes

High precision

Moderately Fast

Photopolymer is expensive ($700/gallon)

Laser is expensive ($10’000),lasts only about 2000 hrs.

CHSCHSUCBUCB Séquin’s “Minimal Saddle Trefoil”Séquin’s “Minimal Saddle Trefoil”

Stereo-lithography master

CHSCHSUCBUCB Séquin’s “Minimal Saddle Trefoil”Séquin’s “Minimal Saddle Trefoil”

bronze cast, gold plated

CHSCHSUCBUCB Consumer Electronics PrototypesConsumer Electronics Prototypes

Role of 3D Hardcopy -- Part 1:Modeling and Prototyping

Packaging of various electronics components.

Custom designed housing for other utility products.

The physical frame for an “instrument” …

CHSCHSUCBUCB Prototyping Consumer ProductsPrototyping Consumer Products

“Solarcator” and “Contact-Compact”

Two student-designed “products” in ME221

http://kingkong.me.berkeley.edu/html/gallery/Fall1999TradeShow/

CHSCHSUCBUCB Model Model Prototype Prototype Mold Mold Part Part

Injection-Molded Housing for ST TouchChip

CHSCHSUCBUCB Artistics Parts, Abstract SculpturesArtistics Parts, Abstract Sculptures

Role of 3D Hardcopy -- Part 3:Maquettes for Visualization

All-round inspection, including light and shadows.

Parts that could not be made in any other way …

Prototyping modular parts, before an injection mold is made.

CHSCHSUCBUCB ““Viae Globi” SculpturesViae Globi” Sculptures

FDM maquettes of possible bronze sculptures

CHSCHSUCBUCB Sculpture Design: “Solar Arch”Sculpture Design: “Solar Arch”

branches = 4 storeys = 11 height = 1.55 flange = 1.00 thickness = 0.06 rim_bulge = 1.00 warp = 330.00 twist = 247.50 azimuth = 56.25 mesh_tiles = 0 textr_tiles = 1 detail = 8 bounding box: xmax= 6.01, ymax= 1.14, zmax= 5.55, xmin= -7.93, ymin= -1.14, zmin= -8.41

CHSCHSUCBUCB Competition in Breckenridge, COCompetition in Breckenridge, CO

CHSCHSUCBUCB FDM Maquette of Solar ArchFDM Maquette of Solar Arch

2nd place

CHSCHSUCBUCB Which Process Should You Pick?Which Process Should You Pick?

Do you need a prototype (not just a model)?

SLS, FDM (for robustness, strength).

Do you need a mold for a small batch?

SLA (for smooth, hard surface).

Does part need multiple colors?

3D Color-Printing.

Does part have convoluted internal spaces?

3D-P, SLS, SLA (easy support removal).

CHSCHSUCBUCB Informal Process Ratings MatrixInformal Process Ratings Matrix

Hollow Sphere

Hollow Sphere with Drain/Vent

2 Nested, Perforated Spheres

3D Hilbert

Pipe

Preassembled Gear

Mechanism

LOM (F) F F D F

SLA (F) D C B D

FDM (F) F C C D

3D-P (F) A A C B

SLS (F) A A B B

Documents

ME 290P -- October 2002 Rapid Prototyping and its Role in Product Development Carlo H. Séquin EECS Computer Science Division University of California,