What do you think, is the most practicable way to do the heatbead/build surface when printing BIG. Like bigger parts than 50x50cm in X&Y. I am a little concerned, that if I do it like on the smaller printers I have, I am going to fuse the print permanently onto my print bed. And I am not sure about using interchangeable build-plates, either. Because: How to mount them this big and make sure, that they don’t bow upwards in the middle?
Do you have any realworld experience?
I do PEI with 468mp on glass over an aluminum heat spreader. But it’s not flexible of course. You could do PEI on spring steel. See if you can put a tiny concave on the spring steel, then when clamping to the bed you reverse the camber and it should hold flat with that slight preload.
How about stick PEI to a very thin steel sheet, use aluminium heated bed that have some strong magnet underneath so it will pull the steel sheet flat against aluminium?
Look at 3ntr A2 (or smaller A4) professional 3D printers: PEI on carbon plate.
Another angle is to heat the chamber, and use a big sheet of G10/G11/FR4 type laminate for the bed. Light and strong enough to be removable. Should be flat enough if the piece is >3mm thick.
Ryan, just thought I’d throw in that I have some Garolite X 12x12 panel, 1/4" from McMaster and it is substantially warped, in case you had any thoughts on that one.
@raykholo 1/4" was warped? That sucks. The 1/8" I’ve bought from them in the past has been great.
My Alaska90 has a 600mm x 600mm build platform, built up from a very thin PEI sheet, for adhesion, glued on top of a 1/8" aluminum plate, for flatness and heat spreading, and supported by a laminated wood frame. The best material I’ve found for big parts is PETG, since it curls less than PLA and way less than ABS. 400 watts of 120VAC silicone heater pads glued underneath is barely enough to keep the build surface at 80C.