Printing in PLA. The corners do lift. The bed is glass, but I’ve tried with masking tape and without to see if things would stick better. Doesn’t seem better either way. With the bed temp at 70 the corners still lifted.
I level pretty much before each print, and it seems like usually when the nozzle is at the center I can’t slide a piece of paper under it. At each corner I level it so the paper is just starting to catch between the nozzle and the bed. The glass may not be perfectly straight
I was going to try a brim, see if that helps the warping and maybe sticking. Then again, the buildtak surface looks nice, so I’ll probably get that. Hold off printing anything until that gets here, don’t want to waste more material.