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PETG Printing Issues: Too much heat?  

Active Member
PETG Printing Issues: Too much heat?


I am having trouble getting good PETG prints in my XL.

In particular when they use the whole bed. Same prints in PLA work just fine.

With PETG, lots of different issues appear, low quality, string, deformation, under-extrusion, and sometimes clogs.

Our printer is in a little, insulated for winter, storage room....

I just noticed than a 20h prints would raise the room temperature from 21 degrees at the start to 30 at the end.

I suspect the XL with hours long, full heated bed prints, is just generating too much heat.

Anybody experiencing similar issues?


Posted : 06/11/2023 8:03 am
Trusted Member
RE: PETG Printing Issues: Too much heat?

Such large PETG Prints should usually be done in a chamber. So 30c° sounds good - 35c° might better.

I needed some time to dial in PETG. Theese things worked for me:

- My XL orints hot I needed to lower Nozzle Temperature

- To counter Warping I use 3d Lack for Prints that might warp without perfekt adhesion (not necessary)

- I noticed PETG needs to be really dry. I usually lut Filament Dryer to 50c° and let the PETg sit there for an hour or two at least and then start the print. Also I store Airtight.

- I use a 0.4mm nozzle for everything Toolchanging or anything that needs to look good. IMHO 0.6mm nozzles only work for Prints where printing fast a lot of material is important and details are not important

- Sometimes a little bit of filament can get stuck under the Nozzle. I read for others this leads to the printer reporting a failure, but for me this results in a too high z height, which later results in the Print detaching from the build plate.


I still have warping - that is just the Material. What you can do is print the parts in the right direction or split the part into subparts or even use carbon filled PETG.

Posted : 04/12/2023 1:13 am
Extra Fox
Estimable Member
RE: PETG Printing Issues: Too much heat?

Yeah, PETG is quite sensitive to drafts. If you can control the airflow around the printed part, it will be less likely to lift. I also will leverage brims for larger parts as well. To ensure everything stays true to the build surface.

I suspect because of the lower print temperature for PLA, it's not as susceptible. 

You have to play around with the variables for the environment your printer is in to figure out what works, but I'm sure you'll find the sweet spot.


Posted : 04/12/2023 5:19 am
Estimable Member
RE: PETG Printing Issues: Too much heat?

So far I have no difficulties with Prusament PETG on the textured sheet. I used 0.4 and 0.6 nozzles with the standard print profiles. All tools have the silicon socks fitted.

Even with long parts (402mm x 30mm x 40mm) I had no problems. These parts are part of the enclosure I am building. What seems to be crucial is that the PETG filament has to be really dry. The 0.6mm nozzles seems to cause more problems than the 0.4mm nozzle with the same filament. As already discussed in other threads and shown in several current YT videos, the 0.4mm nozzle can solve a lot of problems.

Posted : 05/12/2023 11:15 am