Re: [rp-ml] A lot of questions..

Date: Mon Sep 12 2005 - 18:08:02 EEST

In a message dated 05-09-11 14:02:31 EDT, you write:

 More than eleven years ago I feel interested in the posibilities of RP
technologies, we made then a little piece in a SLA machine. I´m an “amateur” in
this field, now I´m working in architectural scale modelling, making several
projects through service bureaus in different technologies. It´s a hobby for me
think at better and cheaper methods on 3D printing, for this I want to make to
the list a few questions:
 I read some about studies on the use of a photopolimer film, instead to be
cut by a knife or a laser, exposed trough a lcd screen that project the
corresponding shape onto the last layer. An other approach could be the projection of
the layer shape trough a lcd cannon, always thinking in avoid the XY scan
over the film. Perhaps this method has the trouble of the light dispersion on
borders, and the precise control of the depth of polimerization.
 Does somebody knows if exists a photopolimer that meets these requirements?
It should be inexpensive and easily to remove in a solvent, thinking always in
a stack of sheets to avoid support structures, then we need to remove easily
the waste material.
 Another idea: if we have a polimer film that needs a little of catalyzer to
activate polimerization (or photo activated pol.), we could use a kind of
photocopier cylinder to spread a black powder (like a toner) that contents the
catalyzer. If exists a powder than itself polimerizate the exact shape of the
layer, wonderful! Then we don´t need light..
 If we need light (UV or visible), a black catalyzer powder spread over a
transparent film would help to avoid the polimerization through previous layers,
moreover than we only need an illumination over the whole layer, instead a XY
scan over the layer´s shape. Excuse me if I don´t know well the state of the
art, take this words like a friendly chat with an ignorant guy.
 Best regards
 Guillermo Theus
 Málaga - España


I believe that most of the variations you mention above have been either
tried or are described in the literature.

There have been so many variations in the technology at this point, that in
order to make progress you really need to study quite a bit to know if you are
describing something new at all. For example, there are now well over 3,000
US patents and published patent applications, and this by itself is an enormous
body of material. Add to that similar masses of material from the EPO and
academic publications, and you get the idea that to actually assess the state of
the art is a great deal of work.

However, I'd encourage you to continue working at invention in the field.
Some of the most unique work in technical areas comes from so-called "amateurs."
 I'd recommend starting from a different premise, though. For a new
technology to be successful, it will have to solve some of the fundamental problems of
RP today; for example: speed, accuracy, size or cost. Look at your solutions
in terms of solving one or more of those problems. If it does, pursue it and
study similar existing technologies to see if you have something novel. If
it doesn't - think about something else that does.

Another way of looking at the technology is to find an application of
economic importance and adapt existing additive technology to it. That's what the
too-often-mentioned Align Technology did with their InvisAlign (TM) orthodenture
system. And that's why - at least at one time (and possibly still) - they
held the record for venture funding of a medical start-up.

Ed Grenda
Castle Island Co.
19 Pondview Road
Arlington, MA 02474 USA
781-646-6280 (voice or fax) (email)

The Worldwide Guide to Rapid Prototyping

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