Build Your Own SLA/SLS

For a top down printer, I was thinking, for a continuous print (and not a large surface area), would the print be affected if a Teflon coated screen was continuously moved back and forth as the projection was shown? I'm concerned that the resin would still stick somewhat to the Teflon and the particles that were normally being cured would move with the screen.

Did you mean bottom up? If so, two SLA printers that I can think of off the top of my mind that use a sliding resin tray are the B9 Creator and the Autodesk Ember. So yeah, if you're thinking bottom up I think your idea would work.

Where did you find that image? Google image search cannot find it anywhere. I wanted to know what they were thinking by the air gap. By the way, minus the salt water and the air gap and you have the ZBuilder Ultra.

The B9 Creator and the Autodesk Ember used the sliding method because of the problems associated with hydraulic sticking. There was no chemical bonding whatsoever to the nonstick surface, just ordinary hydraulic action. The way it works is, the part is slid over to the deep end of the resin tray and then it can be lifted into position for the next layer without hydraulic force acting on it and once lifted it can be slid back over to the exposure position. Mike Joyce (inventor of the B9 Creator) filled for a patent, I remember him saying, around the time of the disclosure on the Yahoo DIY 3D printing group.

I meant for a top down machine. Viscosity and surface tension affect my prints so I am looking into using a screen as well to flatten the surface of the resin, similar to bottom up. And it is for continuous printing, where the build plates constantly lowers and I play a continuous exposure. The picture should help explain a little better.

Gotcha. Thanks for the drawing. Yeah, this would be exactly like the ZBuilder Ultra, but with a moving top plate. Or maybe even a continuously moving belt or disk. I think it is very promising area to explore. If one can move the uncured resin into place via this method then you would have an idea worth millions.

Yes I have a plan in place for uncured resin distribution so I can print large flat surfaces continuously. I just need to test how much the resin will be affected by the sliding surface.

When dealing with fluid mechanics the velocity of the resin at the screen should be zero relative to the screen, so the resin there will essentially move with it. However that is if we consider the non slip condition. It may be different if the slide is coated in PTFE or some sort of hydrophobic coating. I think the only way I'll know is if I try and simulate it or actually build it.

Interesting. Keep us posted as to your findings.

I wonder how close to continuous CW can get?

Yeah I'm not sure what the threshold for continuous printing would actually be, but I think around 3 frames per second should cut it, especially when moving at 3mm/s.

Interesting work!