Subject:
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Some brainstorming needed.
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Newsgroups:
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lugnet.robotics
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Date:
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Fri, 12 Mar 2004 02:55:46 GMT
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Original-From:
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Steve Baker <SJBAKER1@stopspammersAIRMAIL.NET>
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Viewed:
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894 times
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I've been thinking about trying to build a '3D printer'. These things
exist in a number of commercial products - but they cost an absolute fortune
and I've been thinking about making one using Lego robotics components.
The idea is to take a 3D CAD model inside your PC and to have some kind
of robotic contraption build it for you in the real world.
Some examples of these machines work like this:
1) One contraption had two large bins - perhaps a foot on a side by
a foot deep - each with an elevator mechanism that could raise or lower
the floor of the bin by a fraction of a millimeter. The machine has
one bin with it's floor fully lowered - full of something like dry
plaster powder. The other is fully raised (and therefore empty).
When the full bin is raised a tiny bit and the empty one lowered
by a similar amount, an arm sweeps over the tops of the two bins
and scrapes a small amount of the powder from the full bin into
a thin layer on the top of the empty one. Something like an inkjet
printer head sprays some coloured water onto the newly formed thin
layer to draw out a cross-section of the model. This is then
lowered a little - and the whole process repeated one layer at at
time until the originally empty bin is now full and the full one is
empty. After the plaster dries, you can lift out the object from
the full bin and brush off the loose, dry powder from around it.
2) Another one I saw used a very large roll of adhesive-backed paper.
it would build the model up by unrolling and sticking down a layer
of paper - then cutting out a cross-section with a laser and cross-hatching
the unused areas outside of the model it's making. Layers would build
up one at a time until the entire model can be broken out of the
cross-hatched scrap paper. The resulting model looks like it's been
carved out of solid wood.
4) Yet another had a platform that could be raised and lowered inside a large
tank of some kind of liquid polymer. The platform would be raised to just
a fraction of a millimeter below the surface of the liquid - then a laser
would be used to harden this photo-sensitive liquid in the areas inside the
cross-section of the model. Then the platform would be lowered a fraction
and the process repeated to build up the model layer by layer.
Anyhow - I've been wondering whether it would be possible to build some kind
of contraption that would do this using Lego (and - presumably - a significant
amount of non-Lego parts)...but all of those approaches seem to need powerful
lasers or weird chemicals or some-such.
So - does anyone have any idea what might be possible for an enthusiastic
amateur?
---------------------------- Steve Baker -------------------------
HomeEmail: <sjbaker1@airmail.net> WorkEmail: <sjbaker@link.com>
HomePage : http://www.sjbaker.org
Projects : http://plib.sf.net http://tuxaqfh.sf.net
http://tuxkart.sf.net http://prettypoly.sf.net
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Message has 5 Replies:
 | | Re: Some brainstorming needed.
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| (...) Wow, Steve, been a while since I've seen anything with your name on it! :) And if you're referring to yourself there in that last sentence, I think you can easily afford to call yourself something a lot better than an 'amateur.' ;) As for the (...) (20 years ago, 12-Mar-04, to lugnet.robotics)
| | | Re: Some brainstorming needed.
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| Hi Steve, (...) how about building a robot that uses a pile of 1x1 plates as raw material? These are even easy to come by in the form of mosaics. Jürgen (20 years ago, 12-Mar-04, to lugnet.robotics)
| | | RE: Some brainstorming needed.
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| Sorry for the double copy Steve, I thought I sent this to the list. I don't have much input (except to say that number 2 is probably easiest - a few mW laser with some optics to focus the beam into a very small point would probably be enough to cut (...) (20 years ago, 12-Mar-04, to lugnet.robotics)
| | | Re: Some brainstorming needed.
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| (...) You can email directly to: lego-robotics@crynwr.com (...) Yes - I had thought about something like that. I was thinking in terms of sheets of thin balsa wood - which could probably be cut with the kind of power I could get from a Lego motor. (...) (20 years ago, 12-Mar-04, to lugnet.robotics)
| | | Re: Some brainstorming needed.
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| (...) The device you describe above is a 3D printer from Z-Corp. (URL) had the pleasure of using one, on loan from Z-Corp for a month. It is a wonderful prototyping device, although SLA (stereolithography) prototyping systems produce superior models (...) (20 years ago, 17-Mar-04, to lugnet.robotics)
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