Build Your Own SLA/SLS

I am trying to make my first print and have had 3 failures. In all 3 cases I get a blob of plastic on my platform (DropLit bottom-up printer, G+ resin, calibrated). My build platform (a small 2.5cm diameter) is not on center. The projector is fixed and can't be moved left to right I can center Y by moving the platform forward/back. I've tried using the Move commands in the slice screens but they don't seem to have an effect.

I think I have my focus calibrated, I place a sheet of paper over the hole in the base and project the image onto it and focus until it is crisp.

I've tried to use reasonable slicing parameters (or so I thought!) for the G+ resin:

3 first layers at 5000ms
layers at 1000ms
.1mm thick layers

10600ms lift and sequencing from autocalc.

I set my Z=0 with a thin trip of paper between the PMS and the build plate. The resin does stick to the Al build plate so that seems ok (although I am sure since it is not centered it is hanging off the side a bit).

I am trying to print a too complex for a first print Rhomball. I will try to find something simpler to print until I have things dialed in.

Forgot the most important part - I'm using an Acer P1283 projector with the UV filter and color wheel removed.

I also figured out how to use X-Y move in the slice window so I am not able to center my object on the build platform. I was also trying to print the original ball pretty small, maybe 1.5cm diameter and had included support. I see now (after scaling it up 3x) that it has support as part of the model. So that might make things a little better.

Now I need to get a handle on the exposure/time parameters although it seems the resin was indeed curing and sticking to the platform.

cheers,
Michael

try more cure time, maybe 3000-6000 ms?