I print in PETG a lot and only Bambu PETG seems to be horrible about sticking to much to a textured PEI plate. I don’t use glue or anything on the plate because any other PETG doesn’t need it. On my textured PEI plates (all from Bambu but different generations of their gold plates) Bambu PETG, Basic and the new HF, are horrible about adhering too much to the bed. Bambu says to let the bed cool but that doesn’t help. I’ve had parts rip the bottoms out when I flex the sheets. It doesn’t just pop off like PLA or ABS once the plate is cooled.
On top of that, when they don’t separate cleanly, the bottoms of the parts have a white film or residue on them that I have to use a torch to burn off.
I have also see where using dark colors like black leaves some sort of residue either on the plate or in the print head that bleeds into the first layer of my next print of a lighter color.
I’ve used a fair amount of other brands of PETG and I’ve never experienced these issues on the same machines with the same build plates. I’d like to continue to use Bambu stuff, especially the PETG HF but this is just getting more and more annoying.
Full Disclaimer, I’m very VERY new into the Hobby, so take everything I say with a grain of salt:
Are you by any chance touching the bed before the print?
I had similar issues with PLA, although not to this extend. Apparently it was caused by either Fingerprints on the Bed, or because I removed it after my prints.
I re-calibrated the Bed of my A1 (Not the “short” calibration pre-print, the one that takes around 10-15 Minutes).
Then I mixed two Cups of warm Water with two Teaspoons of Dish Soap (Specifically one that gets rid of fat), put it into a Spray Bottle and gave it a good shake. Before and after every print, I manually heat up the Bed to 50-60 Degrees and spray the Soap water on it, gently wiping it with a cloth. Because of the heat it dries super quickly.
I just leave the bottle next to my printer. Ever since I started this cleaning routine, tie prints stuck perfectly to the bed without leaving anything behind.
A local print farm uses Windex first. I use a glue stick but that leaves a texture from the the thick spots of glue on smooth plate but not on textured one. I did one large print using spray glue. No issues. I use smooth plates now.
On my Bambu textured plate I used Acetone to clean it when I first got it and now nothing sticks to it without Aqua Net. I didn’t get the memo till 2 weeks later when I started having lifting issues.
I’m still a newbe with only 600 hrs and about 10 spools on my A1. About the same on my Prusa MIni.
Nah, I learned a while back to keep greasy fingers off the bed. Besides, that usually caused issues where PLA wouldn’t adhere. This is adhering too much. And, I do wash the plates occasionally with soapy water but that doesn’t see to have any affect with the the BL PETG.
Just to add a little bit, I did try putting the plate in the freezer after a print for a few minutes and it did help with the release but the part still didn’t pop off on it’s own and still left a residue on the bottom (first photo)
I have also seen this weird phenomena where I get an imprint of the prior print on the bottom of a part (second photo). This comes off when torched but again, this is only with BL filament.
I had some anycubic PETG I accidentally printed in .12, made the prints a real pain to remove, and thought I’d never get the skirt off! (Damn flashforge always defaults to skirt…)
.28mm Again, it’s only the Bambu filaments that do this. Same print settings with different filaments and those filaments have good adhesion but pop off the bed with a little flexing or nudging with a scraper.
Filament formulations vary but in general PETG is known to bond really well to PEI build plate surfaces. Textured PEI less so than smooth ones but it still can bond extremely well and note that this is not a Bambu lab PETG filament only issue.
Stick the build plate in the freezer for a couple of minutes and while still cold try to pop the parts off. This large temperature delta is most of the time enough to get the parts to fully release from the build plate without damage to either parts and/or build plate.
What other filaments have that residue on the bottom? I’ve done the freezer thing and it helped a bit with releasing the BL PETG but it still has the discoloration on the bottom and “remnants” of a previous print.
It actually reminds me of when I have glue down on an Engineering plate for TPU and you can see lines from previous prints on subsequent prints.
Their filament is still quite a bit different from any other PETG I’ve used
including Overture, California Filament, Hatchbox, Eryone, Inland, Paramount, Elegoo and many other random ones from Amazon. None of these other ones behave like this which is why I find the BL stuff so frustrating. I’m just surprised that searching around, nobody else seems to notice this.
These remnants likely come from tiny PETG particles that are still stuck to the PEI build plate from previous prints which also compounds the removal issue.
In the past I cleaned these particles by wiping the build plate with a rag that is soaked in Acetone but note that Acetone can damage the PEI surface if you’d flood the plate with Acetone for too long and also never use it on a hot build plate.
Personally I do use very little BL filaments as they are difficult to obtain and not cost effective in my usage case where I reside. I had some similar issues with some local PETG brands ( e.g. Protej, 4DLab,…) so again it is not a BL PETG filament only in my books.
