CS 285: SOLID MODELING

Lecture #6 -- Mo, Feb. 7, 2000.

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Preparation:

Familiarize yourself with the operation of QuickSlice.
Stydy more of the constructs available in SLIDE.

In the first half of assignment #2 we looked a modeling an object that only had to "look nice" --
now we will find out what it takes to make the object functional and to fabricate it on an FDM machine.

First we take a look at the target fabrication processes:

Rapid Model Making by SFF

Most Solid-Free-form Fabrication (SFF) Methods
use a constructive approach, building the desired model by forming one thin layer on top of all the previously formed thin layers.

One can distinguish two general groups:

SFF by Solidification

The raw material present is polymerized, fused, or glued into the desried solid shape.
at the end of the build phase the ramainder is removed.

Stereolithography (SLA)
Laser cross-links molecules in organic liquid.
E.g., 3DSystems -- SLA series
Selective Laser Sintering (SLS)
High-power laser fuses nylon or ceramic powder.
E.g., University of Texas at Austin.
3D Printing
Glue droplets are dispensed through an inkjet printer head into a thin layer of powder
E.G., ZCorporation.

SFF by Deposition

Material is deposited selectively where it is needed to form the desired shape.
Auxiliary material may have to be deposited to construct scaffolding to support overhangs and arches.

Layered Object Manufacturing (LOM)
Layer 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 is dispensed from a moving nozzle and planarized with a milling blade after every layer.
E.g., Sanders Prototype, Inc. (SPI).

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

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

Designing for FDM and QuickSlice

Analysis: what went wrong in slicing your objects ?

What experiments did you try to understand what QuickSlice is doing ?

What useful tricks did you discover ?

How should we go about placing a hollow spout into the wall of the teapot ?

The use of Boolean operations -- accuracy issues.

Interfacing with Quickslice at the ssl-level -->> resolving booleans in 2D.

L-SIF

Current Homework Assignment:

READ : "The Use of Solid Rapid Prototyping in Computer Graphics and Scientific Visualizattion" -- On-line course notes by M.Bailey from Siggraph'96.
A#2: Get familiar with SLIDE -- and QuickSlice

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