CS 294-3: RAPID PROTOTYPING
Lecture #1 -- Sep. 1, 2000.

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What Is CS 294-3 All About ?

CS 294-3 in the curriculum
A nice complement to CS284: "From virtuality to phisicality"
What you will learn
Rapid Model Making tecniques (mostly by SFF)
Rapid Prototyping tecniques (mostly by NC milling)
Making a pilot batch of parts (mostly by injection molding)
Languages to describe parts for submission for fabrication.
Teaching style, grading policy
This is a seminar-style course: Class participation is important.
This is a hands-on course: Every student will design and build one or more parts.
Course organization
Choosing class time slo: 9:30(sharp) to 11:10

Characteristics of Rapid Prototyping

Rapid turn-around time

Little process planning

Build one item at a time

Additive methods versus subtractive methods

Building versus machining

"Amateur Fabrication"

Introduction to Rapid Prototyping by Solid Free-form Fabrication

(Additive Methods)

Layered Object Manufacturing (LOM)
Layers of paper are glued on top of one another.
E.g., Helisys Corporation -- LOM-2030H
Fused Deposition Modeling (FDM)
Hot plastic or wax is dispensed from a moving nozzle.
A second nozzle deposits supporting material of a somewhat different composition.
E.g., Stratasys -- Our own machine in Etcheverry.
E.g., 3DSystems -- ThermoJet Solid Object Printer.
Thermoplastic ModelMaking
Hot plastic or wax is dispensed from a moving nozzle and planarized with a milling blade after every layer.
E.g., Sanders Prototype, Inc. (SPI).
3D Printing
Glue droplets are dispensed through an inkjet printer head into a thin layer of powder
E.g., ZCorporation.
Selective Laser Sintering (SLS)
High-power laser fuses nylon or ceramic powder.
E.g., University of Texas at Austin.
Stereolithography (SLA)
Laser cross-links molecules in organic liquid.
E.g., 3DSystems -- SLA series

On-line course notes by M.Bailey from Siggraph'96.

Rapid Prototyping of Solid Three-Dimensional Parts" Technical Report by Sara McMains

Rapid Prototyping by Machining

In Numerically Controlled (NC) Machining material is removed by a cutting operation:

Turning
- - Piece turns on a lathe, cutting tool is stationary.
Drilling
- - Piece is fixed, rotating tool drills cylindrical holes.
Milling
- - Piece is fixed, rotating tool removes pockets of material.
CyberCut
= 3-axis milling + Reference-Free Part Encapsulation (RFPE)
- - Piece is encapsulated in plastic, which gets replaced after all operations for one access direction have been done.

Producing a Pilot Series

A Successful Prototype may be followed by a series of many parts for product trial:

Casting
- - make a master (e.g., wood -- wax);
- - take a negative mold (e.g., sand -- plaster);
- - cast many copies (e.g., cast iron -- bronze);
Injection Molding
- - directly machine the mold (e.g., aluminum);
- - form parts by injecting hot plastic (reuse mold).

Check out our own FDM machine

A trip to 2111 Etcheverry Hall

First Homework Assignment:

A#1: Surf the Web to find some other SFF services
Try to find a way (and approximate costs) to make a 6-inch diameter globe,
showing the major oceans and continents in relief or in color.

READ : "The Use of Solid Rapid Prototyping in Computer Graphics and Scientific Visualization" --
On-line course notes by M.Bailey from Siggraph'96.