Printing PETG on Prusa MK3

Hi everyone, I’m struggling to print PETG. Ive been trying many diff recommended settings but not luck.

I have the temp at 230, bed temp at 70 fan at 40% fan off for first 3 layers.

Not getting good adhesion on the PEI bed…have tried a glue stick it helps a bit…the prints are looking and feeling underextruded…note no issues at all printing PLA.

any thoughts?

It is quite possible that you are now experiencing a jam due to the under extrusion you might need to take a closer look at your hot end

It looks to me like the z adjustment is too low.

Its printing perfectly with PLA though

do you print PLA on the same build plate? All things being equal I may try a temp tower with the PETG, See if maybe it’s a flyer and needs to print a little hotter. Most of the difference between PLA and PETG is air movement, If you have an HVAC duct close to the printer it could affect it as well more so than PLA.

The last thing I could think of is maybe the filament is wet? Have you tried a different colour in PETG and see if you get the same results? Kinda the elimination game at this point, Unfortunately, its not a fun game but its the most effective.

Same build plate. Its in an enclosure but flaps are open…in an enclosed room. There is a hvac duct in the ceiling but not close by. Just opened the filament so it SHOULD be dry i hope…I’ll try a temp tower and diff filament thanks

ok, thanks, let us know we will get it straightened out.

How did you come to those temperatures? The default PETG settings in Prusaslicer are 240/250°C nozzle and 85/90°C bed for Prusament PETG and slightly lower for Generic PETG. If you didn’t slice with those profiles and simply changed the temperatures on the PLA settings, choose the Generic PETG as the filament and reslice. The volumetric rates for PLA and PETG in the slicer are different. It’s 15mm3/s on PLA to 8mm3/s on PETG, and cooling is also setup properly in the profile too, among other settings.

I have used both PETG profiles in Prusaslicer and have great results with the few brands of PETG I have used.

I have found PLA is very forgiving. It tolerates more variations than Petg. It still looks like the nozzle is too close. I would suggest adjusting it for the petg.

Interesting update…i switched to black PETG and its printing beautifully…so odd…I think i recall a friend saying she had trouble printing white before or maybe this filament had just gotten some moisture in it or something. Printing great now!
Thanks guys!

Assume you have a leveled build bed, PETG does not like to be squeezed as much as PLA, suppose you have a z-offset of -1.50, reduce it to -1.30, try different values, every filament is different.


What are the recommended print settings?

This is for the filament I’m using on a Kingroon KP3s

Bed Temperature - 85C for first layer, 90C for all other layers
Nozzle Temperature - 230C - 250C
By Spool Fuel Seller on March 2, 2022

Hi @ve5yan

Welcome to the Forum, Glad you found us in our little corner of the internet.

Thanks for your input actually a really good point that it may change for each Filament. Be sure to post up any questions or interesting projects you have going on, We would love to see them.