I built one, but it was a (top-down) resin printer, so I don't think I have any useful advice to offer. Also, I kinda burnt out on the project after I came in one morning and found the resin had melted the vat and leaked onto the floor--somehow I just totally failed to consider that the solvents in the resin could obviously dissolve a lot of plastics. Huge mess, huge pain to remediate. At least it was a concrete floor. I got a replacement vat in glass, but I never worked up the will to work on it again. It did basically print before that, but I had a lot of off-layer curing and didn't get to do much work on tuning that in before the accident.