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$40k Filament Extruder Competition

PostPosted: Mon May 21, 2012 5:56 pm
by bdring
Instructables.com has a competition to design a cheap machine to make your own 3D printer filament from ABS or PLA pellets.

http://www.buildlog.net/blog/2012/05/fi ... ition-40k/

Fantastic! Team effort?

PostPosted: Mon May 21, 2012 11:42 pm
by frob
This is a fantastic initiative, i'd love to support it too.
Though I have no time to physically work on any such project directly for several months at this rate,
It would be great to see a community discussion develop here on this-
As we've seen with the extruder discussion, there's a lot of really bright folks here with some great ideas and talent;
Together, with a little out of the box ingenuity and teamwork, I'm sure an excellent candidate design would surface.
I'm already getting some ideas towards that... 8-)

Re: $40k Filament Extruder Competition

PostPosted: Tue May 22, 2012 1:39 am
by Enraged
I think the problem with the whole idea is in general, commercial extruders use a screw with a pitch that isn't constant, and trying to replicate that for under $250 is going to be difficult. It will be very interesting to see what people come up with.

I can see myself build one too, once the contest is over. Being able to make your own filament for your own 3D printer would be fantastic.

Re: $40k Filament Extruder Competition

PostPosted: Tue May 22, 2012 4:02 am
by daveczrn
Variable pitch screw... hmmm. Got a picture of one?

Re: $40k Filament Extruder Competition

PostPosted: Tue May 22, 2012 5:51 am
by awesomenesser
Enraged wrote:I think the problem with the whole idea is in general, commercial extruders use a screw with a pitch that isn't constant, and trying to replicate that for under $250 is going to be difficult. It will be very interesting to see what people come up with.

I can see myself build one too, once the contest is over. Being able to make your own filament for your own 3D printer would be fantastic.


Yea I think the screw is out because of cost.

Is it possible to melt the pellets in a temperature controlled kettle with an agitator (to mix die). (One note is that a vacuum might be needed in most designs to remove air bubbles) But getting the liquid resin out of the kettle/pressure cooker into a consistent filament will be an interesting challenge.

Re: $40k Filament Extruder Competition

PostPosted: Tue May 22, 2012 6:13 am
by amix
Yeah, a picture would be nice! I did not find anything using "variable pitch screw", that would make me feel safe I have gotten the screw being discussed here.

Re: $40k Filament Extruder Competition

PostPosted: Tue May 22, 2012 12:27 pm
by orcinus
No pics needed, really. Extruders often have screws that start up as a high-pitch spiral, then gradually shift to lower and lower pitch the closer to the mixing chamber / nozzle they get. See for example: http://www.spirex.com/media/doc/The%20B ... Design.pdf

It's what gives the extruder appropriate material compression. There are other, more complicated arrangements as well, with the pitch shifting back and forth etc.

Anyways, re: Filament Extruder Competition, there's already been a successful Kickstarter project doing the exact same thing: http://www.kickstarter.com/projects/roc ... ment-maker

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Re: $40k Filament Extruder Competition

PostPosted: Sun Sep 23, 2012 5:17 pm
by Charlie
Hello all.
Just chiming in about variable pitch screws; There are actually two very easy ways to build them for well under target cost here. I have done R&D in industrial automation for a lot of years now, and this is something I have experience with from past commercial projects. Both methods are easily scaled and suited even to small scale production. Its not that hard, just too technically intensive to cover in a forum post.
While not interested in developing and testing a complete entry for this competition - I have other projects at hand right now and limited time - I would not be averse to collaborating with a serious team on their project if variable pitch screws are a necessity, or of simply constructing VP screws to a teams specs for interested teams.

Re: $40k Filament Extruder Competition

PostPosted: Tue Oct 23, 2012 3:54 pm
by TLHarrell