Build Your Own SLA/SLS

I have had a problem printing the base of a hollow cylinder. See photo. Surprisingly, there is no problem with the first few layers, but then one side of the cylinder deteriorates. Even stranger, it then recovers.

Any thoughts?

This seems to be a problem that is worse with SubSF, it doesn't handle the transition from base layer to normal layer times well for some physics related reason I am unaware of. I suggested to Pacmanfan that maybe we can have an option in Creation Workshop to feather the base layer times into the normal layer times. You can try this by editing the gcode manually and changing the layer times. The other work around it to use a higher layer cure time, or raise the part onto supports.

Clearly most of the print is fine. The question is why some regions of the print behave differently. Still searching for an explanation...

I created a test grid and printed it. As you can see in the photo, some portions of the build plate are unusable, while others are fine. I am getting by for now by printing in the "good" area, but I wonder what the issue is.

I "had to " shim the right side of the build plate (between the 3D printed fixture and the aluminum rectangle) because the adjusting/leveling screws were not working at all. Could be a bed leveling issue.

No idea why the picture did not appear the first time. Trying again.

What projector do you use?
There are some people (including me) with Acer P1500, we have uneven exposure issue. Usually, the first base layers are fine, but when it comes to regular layers, there is underexposure and geometry defects.
There is no easy way to fix it, because of construction of the projector itself. But, I hope that software Mask usage will get us good results.

Thanks! Not sure what "software Mask usage" means.

The most recent print I created was perfect. So long as the prints fit in the "good" area, I appear to be OK

Projector is an Acer H6510BD

Jon

In the last version of Creation Workshop, Configure Machine menu, you can find "Enable Mask" option, and use .png image to adjust exposure for some areas of your buildplate to make it even. Check this:

Thank you.

Where can I read about this kind of news, so that I need not ask these questions?