Re: RP definition

From: Ian Gibson (
Date: Wed Feb 07 2001 - 03:28:34 EET


Yes, they can be used for rapid prototyping. But they are not what we refer
to as RP machines. When such machines come into existence, we may have to
call them something else. What a pity.


At 11:31 AM 2/6/01 -0600, you wrote:
>I like what you are saying but, just to be troublesome:
>Suppose a device was introduced that cured a part, all at once, from
>Suppose a device was introduced that extruded a blob through a die whose
>shape changed with time?
>These are definitely not layered manufacturing. Are they rapid prototyping?
>>Dear all
>>I see that the main source of confusion is between what is the definition
>>of 'rapid prototyping' and the definition of a 'rapid prototyping machine'.
>>In my mind, they are 2 different things.
>>Rapid prototyping is a means to and end. It is how we get from an original
>>concept to a final model. There is in fact no need to bring technology into
>>it at all. Why should we start with a computer-generated model? It is the
>>best approach in many cases, but some sculptors for example may see it as
>>an impediment; a barrier in the way of realising their ideas. In that case
>>they may see a more direct, manual route. RP therefore becomes a
>>philosophy, an ideal. In that sense, it can be (and is) applied to software
>>development, PCB construction, even manufacturing plant design.
>>Rapid prototyping machines are however just that: machines. They are a
>>technology that uses layer-based fabrication methods to construct models
>>directly from solid-modelling CAD data without the need for customised
>>set-ups (at least in theory) or specialised tooling and fixtures. In that
>>way, they can be distinguished from CNC, EDM, etc. Also there is no problem
>>with using FFF machines or LM machines as alternative definitions. Except
>>RP machine is just as good, was first on the block and is the most popular.
>>Autofab is a superset, that includes RP machinery as well as CNC machining,
>>robotic machining, etc. and I see no problems with that either.
>>So in summary, you can use RP machinery, CNC machines, or even a hammer and
>>chisel to achieve rapid prototyping, so long as you are using the quickest
>>method available to achieve your objective. With Autofab, you must be using
>>an automated method. If you are using RP machinery, you are using a
>>layer-based technology.
>>So Lex is developing Autofab technology, which can be used for RP, but
>>which is not an RP machine.
>>Dr. Ian Gibson
>>Associate Professor
>>Dept. Mechanical Engineering
>>The University of Hong Kong
>>tel: +852 28597901
>>fax: +852 28585415
>>It's tragic magic.
>>There are no coincidences,
>>but sometimes the pattern is more obvious.
>>For more information about the rp-ml, see
>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
>For more information about the rp-ml, see
Dr. Ian Gibson
Associate Professor
Dept. Mechanical Engineering
The University of Hong Kong
tel: +852 28597901
fax: +852 28585415

It's tragic magic.
There are no coincidences,
but sometimes the pattern is more obvious.

For more information about the rp-ml, see

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