Looking for hints to what is causing PETG first layer issue
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Looking for hints to what is causing PETG first layer issue  

New Member
Looking for hints to what is causing PETG first layer issue

Hi Prusa Forum

I am experiencing an issue when I try to print a large area with PETG and I hope some of you can help me identify what the cause of it could be. I have not yet been able to print a large square filling the entire bed. Every time I try, it seems to me that surplus filament is slowly building up on the outside of the nozzle and when it is large enough, it drops off on the print.

Textured bed is used with temperature set to 85 degrees. Nozzle is the standard Prusa 0.4 mm. that came with the printer and temperature set to 240 on first layer and 250 on the remaining layers (the standard configuration generated from wizard in PrusaSlicer).

I have just tried to print with a higher temperature for the nozzle (set to 250 for first layer) and it seem to have a (more) positive effect, but before it reaches half the bed covered with print, it dropped of a string of filament and after that I stopped it. I have now set it to 260 degrees for first layer and I am trying same print again.

What do you think? Am I looking in the right direction or do you have other suggestions for me?

Posted : 25/08/2021 7:16 pm
Estimable Member
RE: 1st layer too squished?


Not 100% sure but I would say that 1st layer is too squished as it looks "transparent" on some areas. So you can try to increase a bit the Z-Offset

You can find detailled instruction there -> https://help.prusa3d.com/en/article/first-layer-calibration_112364

Some areas also look "white" compared to others. You can also have adhesion pb. I would suggest to clean you plate with hot water and dish soap and after drying it use a bit of  isopropyl alcohol

Keep us posted


Posted : 26/08/2021 12:27 pm
New Member
Topic starter answered:
First layer


Thanks for your reply. I tried two prints yesterday after I posted with different nozzle temperature settings and the higher the temperature the better result i got. The last print with 260° was near perfect, but I read on another site that going above 250° could damage the PTFE tube, so I don't think this is a permanent solution. 

I will try your suggestion and make a better effort in cleaning the plate, lower the temperature again and try with fan off for first layer (read it here https://help.prusa3d.com/en/article/petg_2059).

I'll let you know how it goes. 🙂

Posted : 26/08/2021 6:40 pm