Build Your Own SLA/SLS

Does anyone have experience with holes forming in sidewalls on top / down setup? See picture any tips appreciated driving me nuts.

could it be air bubbles/ water mixing in?

What type of release mechanism are you using and what is the wall thickness in those areas?
You might try increasing your exposure just a little. Im also curious to know how the parts are positioned on your build platform, are the defects on one side only?

My experience is it has to do with wall thickness and pull tension from the vat bottom when printing buttom up.

Cheers,
hp

I am using the top down method. It seems t be caused be some sorta of pressure do to closing all walls i.e. tube. I am seeing it in other parts with similar structure. The resin seems to want to move in and out of closed structures.

I've never done top down printing, but maybe allow more time for the resin to settle after you move the build plate down on each layer?

I get the same infuriating holes sometimes. I reduced the frequency by increasing the wall thickness of models that I hollow out.

I can't quite figure it out either. Seems like you get a spot that does not cure on a layer and that propagates up. The question is - why does it suddenly fix itself as the build continues?

I was told sometimes holes are caused by dust on the lens.

I have been working with a top down printer design with resin floating on saline water and I was wondering about your problem.
I placed some Makerjuice SF resin in a container with saline water and it separated properly although there's seems to be a "transition" zone where resin and water meet. I am assuming there's a threshold where it is inconsistent and some droplets of water may mix with the resin.
Basically what I am trying to say is that one should avoid to bring the build platform to low or near this threshold since the resin may be contaminated with water and the last printed layer would pull this contaminated section of resin up. Somehow this area remains stuck to the cured layer therefore creating a hole or defect on the object.
What do you think?

i Love holes

cheers,
hp