PETG Woes

I finally feel confident enough to move away from PLA and try something else, so I'm trying PETG.

I'm using Prusa MK3S and slicing in Prusa Slicer with the Prusament PETG default settings. And yes, I am using Prusament PETG.

I'm having a couple issues. The first is that it wouldn't stick to the textured sheet. No problem, I tried the smooth sheet. Stick too much to smooth sheet. No problem, tried glue stick on the smooth sheet. Solved, no I can get my prints loose. Would ideally still like to use the textured sheet with no glue.

Problem 2 is more important. Base layers are great, but randomly, further up the print, I get a glob. Then it keeps running over the glob and triggers crash detection. How do I stop getting globs?

print slower and increase retraction length and speed.
You've got a direct drive extruder so you can run retractions at up to 70mm/s quite happily.
Retraction distance wise start at about 2mm and work your way up untill you stop getting blobs.
So make sure you have retraction ON for layer changes as these are often where blobs appear.

Also try tweaking the printing temperature.

I've seen people claim everything from 225c on up to 255c for best temp for pet-g. So it pays to experiment.

Speed wise, the general consensus is 40mm/s maximum and always adjust downwards.

To get your first layer stuck - run it slightly hotter and a lot slower - say 5% of the maximum speed.
Yes that is SLOW. And frequently your first layer is 50% or more of the total print time - but if it works - who cares :-)

Actually I think I found my blob problem. I'll try your suggestions if tightening this up and changing the nozzle doesn't help. Thanks.

Attachment 14573Attachment 14573

ok, problem solved.

The globs were from a leak. I accidentally loosened the heatbreak when changing the nozzle, tightened everything up, it no longer leaks.

As far as the textured sheet, I was given the suggestion to rub the hell out of the sheet with a mr clean magic eraser. I did so, and now it works great, so I can use both sheets without issue now.