Well, I too am experiencing the bubbling of my pei sheet on the Taz 5. The printer is about 3 months old and I have a few hundred hours of printing on it. I have only used hips and have always had a problem with the hips warping on longer prints. I started using a 20 line brim to counteract this and at first it was helping some. Now even my brims are starting to peel up in spots and then the whole part starts to lift and curl. It seems if as my sheet has lost it’s stickiness. I just got a mini in the mail yesterday and I have so far only printed in pla on that. But the parts are sticking to the build plate like glue. I had to use the clam knife to pry them off. I remember when I first got my Taz and it was the same way. Is there any way to make it sticky again without adding gluestick or lulz juice? I think I saw someone say something once about using sandpaper to rough it up a bit. If this works, what grit should I try? Something rough or something fine? As always thanks in advance for any help. I’ve been at it 3 months but I’m still a noob.
I did use sandpaper on mine (not PEI from Lulzbot but installed myself on a TAZ 4) I used 1200 grit to just lightly sand (just take the gloss off) then cleaned off the dust with a damp paper towel and print.
I have printed hundreds of things on mine now in ABS and PLA (no hips) and other than make sure the bed is level and minor Z axis adjustments I do nothing else to it.
Oyher than bubbling, the PEI sheets should last a while. Depends on how much damage afflicted when removing prints. It doesn’t lose “stickiness”.
To clean isopropyl alcohol is fine every so often. IPA does dry out PEI eventually. Fine grit sandpaper (I’ve been using a Mr. Clean Magic Eraser) helps to remove some of the dust and oil. I suppose diluted dishwashing liquid could also remove oils.
Ultimately, lowering the nozzle is key to adhesion. The end stop knob can be finicky, so adjust by eighth or sixteenth turns. I find the z-offset in slicing software gives you even further granularity than the end stop knob. Negative value for z-offset gets nozzle closer for better adhesion, positive off-swt value moves the nozzle higher for less adhesion. I try to stay aware of how the print comes off the PEI at 50C, and adjust by .05 or .10 for the next print (if done in succession).
FWIW, my PEI is starting to bubble also. I think its the humidity… If i replace the PEI, I’m going to figure out how to seal the edges better… Clamp the edges or seal with silicone. For the time being, I’m starting to play with raft settings until I can figure out what the next steps are.
Thanks for the replies. I’m at a level now where I leveled the bed corners first with a digital indicator and then set the z end stop. My bed is pretty much perfect as far as the level goes and if I drop the hotend even a hair more, I start to get artifacts in the print that looks like the nozzle is dragging through the layers. I’m actually printing out a cosplay stormtrooper helmet right now and I just arranged the part to where it wasn’t on the bed where I have been having issues. This is a 17 hour print and when I put the pieces together they have to fit pretty good, so I don’t want any curling. So far with moving the print, everything including my brim and the actual part itself, seems to be sticking pretty good. When this print is over I will take some fine grit sandpaper and lightly sand what I consider the bad spots to see if that helps. Thanks again guys. I don’t know what I would do without this forum and this community.