RE: rp definition

Date: Mon Feb 05 2001 - 23:39:12 EET


OK, I can't help it any longer. My two cents:

The definition:

Of the many definitions I have seen so far, I like Marshall's best. His
seems to state the goal of the device as opposed to describing how it
works. I don't care what's inside that Digital Fabber, I just want to

1. When can I get my part.
2. How accurate is it?
3. What are it's material properties?
4. and maybe "How much does it cost?"

Terry's expressed intent is to identify machines that follow a certain
paradigm in their function. (Even though (a) their physical principles
vary widely, (b) their operation speeds vary by an order of magnitude, and
(c) their accuracies vary by an order of magnitude.) To reach Terry's
intent, I would choose a new name: additive processing, layered
manufacturing, ...???

The arguement that RP devices are capable of "freeform" prototyping is
supposed to identify RP devices as the only machines that can build "any"
geometry (if I interpret the term correctly). But don't we find that there
are geometric limits on every machine. Even the RP devices have minimum
wall thicknesses, minimum radius curves, minimum layer thicknesses, etc.

My definition would be quite short, focusing on the meaning of the title:

Rapid Prototyping:

A class of techniques that rapidly and automatically produce physical
prototypes from a 3D geometry file without the need for skilled operator

Let's just keep it simple. I wouldn't add to or change the definition as
technology changes.



Charles L. Thomas
Associate Professor
Department of Mechanical Engineering
University of Utah
50 South Central Campus Drive
Salt Lake City, Utah 84112
FAX (801) 585-9826

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