Top-Down SLA Printer

[ABearden]

Tore the projector down further. Removed the focal length ring and filed down the focus stop to allow focusing at very close range then put it back together and fired it up.

SUCCESS!

Got it to focus at about 8" or so with roughly a 4"x3" display which gives a resolution of about 0.099mm per pixel at the native 1024x768. Trying to decide if that's enough, or if I want to half that by using 2"x1.5". That would require extending the focus a bit more, but we can print that!

Without the color wheel in the way, I get a black and white image and that 200W xenon bulb puts out enough UV to cure in about 3 seconds at that range. Did some testing in the kitchen on wax paper curing resin and got smoke after 10 seconds; kind've expected since the curing process is exothermic plus the UV heat input.

I did introduce a flicker to the screen, so I think one of the connectors is lose but it should be easy to correct.