Charles,
This definition is interesting (though perhaps more significant to
"historians" who want to write about this era than to people currently
involved).
There's another possible component which I've missed in following this thread
(sorry if I just haven't paid close enough attention to every word - shop
deadlines). I wonder if the following would be helpful:
What about looking at the "origin" of each technology? It seems to me that
there is a group of new technologies which owe their very existence to
digital computers. Although the new technolgies might be "conceived"
before modern information processing, they could not be practically
implemented without it. [[Don't worry about the person who says the pyramids
were built by (big) bit-by-bit layered additive fabrication.]]
This "computerized origin" would probably include all the "revolutionary" new
technolgies - but not the more established ones which are more properly
"enhanced" or "advanced" by the integration of the computer (such as milling
machines which are highly competitive and are computerized - but were not
"born of the computer." )
One side of me likes the alternative all-inclusive approach, but the other
side just isn't satisfied without a better grouping of the technolgies by
their most fundamental nature. Of course, we'll never entirely agree - even
with ourselves.
Oh well, humble food for thought.
Norm Kinzie
In a message dated 2/6/01 12:51:21 PM Eastern Standard Time,
cthomas@eng.utah.edu writes:
>
> I like what you are saying but, just to be troublesome:
>
> Suppose a device was introduced that cured a part, all at once, from
> photopolymer?
>
> 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?
>
> Regards,
>
> chas.
>
>
> >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.
> >
> >IG
> >
> >Dr. Ian Gibson
> >Associate Professor
> >Dept. Mechanical Engineering
> >The University of Hong Kong
> >tel: +852 28597901
> >fax: +852 28585415
> >email: igibson@hkucc.hku.hk
> >
> >It's tragic magic.
> >There are no coincidences,
> >but sometimes the pattern is more obvious.
> >
> >For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
>
> Charles L. Thomas
> Associate Professor
> Department of Mechanical Engineering
> University of Utah
> 50 South Central Campus Drive
> Salt Lake City, Utah 84112
> (801)585-6939
> FAX (801) 585-9826
>
>
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
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