Registered: 1436301426 Posts: 327
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This is probably old hat for the veteran printers out there, but I'm quite proud to have successfully printed PLA on glass! I don't have a heated bed (not that it's necessary for PLA from what I understand), and I used Elmers purple glue stick on a pane of window glass from Home Depot. I had problems in 2 areas at first:
1. Using binder clamps to hold glass in place caused the glass to bend up at the center, making it difficult to level properly. I fixed this by securing the edges with blue painters tape. The aluminum bed has a wide layer of kapton that I never removed, and it seems to help as well. 2. Proper leveling. The tolerance for out-of-levelness seems smaller for glass, but once I finally dialed it in I printed to almost the extent of my print area without warping. Happy printing to all
Registered: 1468212644 Posts: 52
Reply with quote #2
I used a thick glass sheet for a while when I first got the machine. Unfortunately PLA was I think the only filament that really worked well for me. It was always a struggle with ABS, either it would curl off, or using ABS/Acetone slurry it would stick so hard I would wonder if I was going to shatter the glass getting it off (both cases generally resulted in a bad surface finish). I had a tempered sheet, and I was always wary of thermal shocking normal glass (Borosilicate might be more resilient). Although if you run the glass cold it's probably a non-issue.
Two improvements which ended the constant battle with bed adhesion were 1) heated bed, and 2) PEI sheet. There is another thread on PEI, but the short version is for non-PLA filaments those two things are the only thing that worked for me. PLA is an exception. It works okay on PEI if the bed is ~60C, and squashes a little on first layer, but it is probably slightly better on glass (although I always had trouble with tiny islands not sticking on glass). Of course clamping a glass sheet on top of the PEI is always possible too. On the PEI one nice thing is you don't need to constantly clean and reapply glue or spray or anything. Usually just alcohol wipe, and if adhesion ever gets worse then buff it with 600 grit sandpaper (which almost restores it to "sticking too hard" state). Recently I've only been using PETG (latest spool running at 245C). I actually have two brand new spools of ABS that I don't know if I'll ever use (between smell/warping/adhesion problems I don't think I'll ever buy another ABS spool). PETG just works a lot better. It is a little weird on adhesion though. It won't stick for anything on cold PEI, but if the bed heat is ~60C it will stick perfectly for the whole print, even tiny little islands. Usually it pops off at the end pretty easily, but there is a trick I've found when it sticks hard (saw it online somewhere) - you simply drip some alcohol on the perimeter and it will wick under the part and eventually it will release. Anyway good luck with it.