Given all was BL I was hoping this would be simple, but alas!
Printer: Bambu Labs P1S with AMS
Filament: Bambu Labs PETG Basic Gold
Slicer: Bambu Labs Bambu Studio
Plate: Bambu Labs Textured PEI plate
Bambu Labs P1S 0.4 Nozzle
New printer, and I’m a noob at this, so do go easy on me
I want to print in PETG as it’s ideal for plant pots.
Filament arrived, printed out the planter and had artifacts (as I too have holes) that were described in the Thrawn PETG thread. So in Speed options I switched off “Slow down for overhangs” and set Bridge to 200 mm/s and reprinted, while the hole artifacts/scrapes are gone (woo hoo), I now have a funky beard affect, which I didn’t have before. Bobbles of filament are all over the place…
I have read many threads on PETG, but couldn’t pull out what the definitive thing was needed to print PETG well, lots of suggestions but I can’t work out what works and what doesn’t. So could some kind soul guide me into getting rid of this beard effect?
The filament has been dried in the in the kitchen fan assisted oven at 60c, Bambu Studio shows green and 4 out of 5 bars for the desiccant. Loads of desiccant in the AMS and Hygrometer is sitting at 10%.
Settings changed from Bambu PETG Basic:
Changed as per planter design:
Quality → 0.16 Optimal
Wall loops ->3
Top shell layers ->5
Bottom shell layers ->5
Changed to prevent PETG hole artifacts:
Internal solid infill pattern → concentric
Spares infill pattern → octagram spiral
Speed → “Slow down for overhangs” → off
Speed ->Bridge → 200 mm/s
I too had trouble going from PLA to PETG. I was having excellent results with PLA and was looking forward to making the step to PETG. I was guessing my failures were mostly the result of the filament not being dry enough. I used the PETG filament dry program on the X1C and that seemed to melt much of the filament together (making it unusable). Then, I had an extruder clog and felt safer to replace the 0.4mm hotend while I had everything apart (for the first time). Anyway, I have given up on PETG for the time being. I returned my unopen spools of Sunlu PETG and have gone back to Bambu PLA,
Unfortunately neither of the above responses are helpful to you. This is not a result of wet filament, it is a result of the filament not being cooled quickly enough and/or the outer wall is being pushed out past the perimeter by the internal walls. I suggest don’t use concentric spiral for your infill as it will lay down the walls in a very fast method (for a circular model) but will cause the wall to be pushed out even more. For this print, I would just increase the walls so that it is solid (can set to 50 if you want, will have the same effect as being solid infill) but show down all wall speeds to ~50mm/s or slower. It will take longer to print but will look better. Keep the 0.16mm layer height so the filament has a chance to adhere to the previous layers. You could also do variable layer height and go 0.08 for the sloping section up to 0.20 for the small lower part. The slope of the walls on this planter are on the limit for the part cooling ability of the printer so it needs to be slowed down a lot to look good.
I would also suggest printing both pieces separately.
I initially could not get good prints with PETG. Printing a temperature tower showed that I needed more nozzle heat than either Bambu or the filament manufacturer suggested. That alone made a huge difference in adhesion and reduced stringing. Then I ran the calibration tests in OrcaSlicer (the top line calibrations, not the tests inherited from Studio, next to Project) for flow rate and pressure advance. With those settings, nearly all of the defects are gone, and the rest are usually my fault or related to model geometry and cooling. I prefer the OrcaSlicer calibrations because the settings are not erased by a printer reset, which seems to be needed after a firmware update. Running the calibrations takes some time, but by testing a range of settings all at once time is actually saved compared to repeatedly reprinting with one or more settings changed at random.
I swapped slicer to Orca, performed Heat, Flow and PA tests and amended Orca settings.
When I slowed it down and made it solid, I never managed to get to print the cup bit as the nozzle clogged doing the legs. It also took 12 hours to print v 3 hours. Reverting back the speed and undoing the 50 walls, but keeping all other suggested settings I got the cup printed but produced there was no real improvement on the beard affect.
I believe this to be a side affect of the Thrawn changes, the slow down for overhangs, so I am now undoing that…
I’m going to look into your settings I could never get Bambu’s PETG to successfully to print with Bambu’s PETG profile. This is interesting if it’s only a cooling issue.
I read @skyme thread (cheers!), and upped min fan speed threshold to 40 and max to 90.
Still some beard right at the bottom of the cup and banding affects all over but considerably better!
Looking at the builds on thingiverse (Hydroponic, Self-Watering, Seeds starter, Robert Planters) 400 prints with only 16 mentioning PETG, all those look amazing but done with Prusa’s and no Bambo Lab PETG prints. So not sure I can equal let alone better the Prusa for quality of PETG prints. If anyone pulls a good print off with a BL do share
The other thing you might try is to leave the top off or front door open when printing (assuming it’ll print this way – never tried either.). It might be the enclosure is trapping too much heat and it’s causing you to get sagging on the overhangs. PETG should require you to print it enclosed.
Well speaking from experience, up to now, I’ve always printed PETG without an enclosure. It also may depend on the PETG being used. I’ve printed Polymaker, California Filaments, and Amazon Basics brands on open frame printers using a 75C bed and 235C hotend.
I would run your temp tower calibration, then flow rate, then pressure advance when you try out a new filament. I just got some BBL PETG-CF Thursday and completed my first print with it in my P1S Friday evening and it turned out great. The first temp tower had artifacts like your prints with stringing everywhere. Default profile needs adjustments (Orca Slicer), had to increase the extruder temp to 265C and using the High Temp plate at 55C. Using the High temp plate with BBL PETG-CF requires you to use the adhesive solution or suffer your part being destroyed trying to remove it from plate. I use the liquid one with the applicator built in. It works great with PETG-CF.
I have tried everything in this form and doing some maintenance to the printer as well but I can’t
get the Bambu Lab PETG Basic to print an overhang greater than 15 deg without a bearing effect or sagging. The silver is BL PLA and the black is the BL PETG. I have the P1s and it is not more than 3 days old. Any help would be great.
the bottom line is that BL don’t understand 3D printing very well. They got the mechanics right and that was that. All their filament profiles are wrong. I have had no problems with PETG, but then I am not expecting incompetents to hold my hand.
I agree that cooling is probably the issue. Are you printing with the doors open and the lid off? I use the default print profile for PETG and have never had this issue. But I leave the door open and the lid off.
