Build Your Own SLA/SLS

BeamMaker: an open hardware high resolution digital fabricator for the masses

Authors claim is can be built for $380 USD.

Build instruction with code, and schematics for laser cutting:
http://www.tesis.uchile.cl/bitstream/ha ... sequence=1

You can translate the instruction to English using your browser with this link:
http://www.tesis.uchile.cl/bitstream/ha ... sequence=3

Research paper abstract
http://www.emeraldinsight.com/journals. ... 8&show=pdf

I would not use Plexi for the Z axis, it has quit a bit of strain on it to last long it would need to be build stronger IMO to last.
That price is about on par with most builds I would think, if you look through the full article the total cost with a 1024X768 DLP projector comes out to $700 USD. I have approx. $900 into my build but the projector is a 1080P which cost 2X that of a SD projector. So the price is about the same as most who build or a bit higher IMO.

It would however be a great printer for someone who had a laser cutter on hand if they beefed up the Z axis.

Clinton

This one is even simpler.

SLA using a DLP with a bottom feed mechanism
http://www.youtube.com/watch?v=Cu5b8y-JGfw