Build Your Own SLA/SLS

Hi again.
My first attempt to create a DLP 3D printer was a bottom-up.
But me and my friends give up to that design.

Now we are building a top dow style.
We are printing the first test object.
The Projector is a Optoma hd200x DLP
Fun To Do castable resin (color red).

Print tests: Cubes 1x1 cm

I have try to set the brightness to 25, the contrast to 50, 40, 30.
The result are even worse...

layer height = 0.1mm
Litf = 2mm
first layer time = 4sec
others layer = 2sec

What do you think?

Underexposure. The layers do not stick together. For that projector you probably need to (depending on the distance from the print) to use 4 to 12 seconds exposure. On an acer with 3000lumens I use from 2 to 8 or something.
Also the resin seems to be translucent and that is not ok as the light will not only cure the first layer but anywhere under. If the resin glows when printing the prints will sag underneath. The shape must be very clear on the surface layer.

Hi thanks for the answer
Yeah I know that now :\
In these days I have done a lot of experiments. Now I have done some pretty good print.

The resing is good but not soo good... as you said it's a bit translucent and it took me long time to find the correct (or maybe it's bettere to say a quite balance) calibration...

Last night print. 0.1mm layer height.

At the moment I'm printing the same ring at 0.05mm.
From now I'll post some photo in the other section. I'll open a new thread

Still way too transparent.
This was my case 2 days ago:

And after pigmentation (check the holes in the head)