PETG problems

Hi guys,

I just started playing around with PETG. The first print came out pretty well. Now everything I try to print, the plastic gets wrapped up in the nozzle and it pulls the layers off.

Nozzle temp: 240




Any idea what is going on?

Temp seems low, what does your plastic manufacturer recommend? That is also ridiculously fast for printing, try 30mm/s and slowly try and work up from there.

What hotend are you using? If it has a Teflon tube in it, might want to check the condition of the part where it meets the hotend.

The manufacturer recommends 240 degrees. I am printing with a teflon lined tube and I believe 240 is the max you can go with teflon. I guess I need to get an all metal hot end and go to a higher temp. I’ll try slowing it down as well.

Do I need to change the retraction settings going from PLA to PETG?

PET can be really stringy. Some folks can get it to print like PLA, but I’ve not been able to, it’s still stringy for me, so I just print one part at a time. I’m running an E3d all metal hot end. 240C for the filament and 60 for the bed. 40mm/s for perimeters, 35mm/s for external perimeters, 55mm/s for infill. I have a delta printer though, so I can get away with faster speeds. Retracts are 2mm at 40mm/s. I’d go with what Ryan suggested and just slow down, you may, or may not need a new hot end, but if it has a plastic liner, check it every now and then to make sure you’re not melting it.

I changed out the roll of PETG for a roll of carbon fiber PETG form the same manufacturer with the exact same print setting and it came out amazing.

I thing the PETG had absorbed too much moisture. I will try drying it out and see if that fixes it.

Super impressed the carbon fiber PETG though. It’s very strong and ridged. It’s pretty cheap as well. I got it here.



Can you get the throat of your extruder any further in? You really want to get it as far in as you can (just don’t hit the bearing). This dissipates the heat much faster, for better prints. PETG temps also kill the PTFE sleeve really fast and with such a long higher temp zone you will be changing it out pretty often.