PETG vs PLA printing

RAGII

Member
I printed some "hinges" for FPV racing gates that we found on thingiverse. The first couple I printed out of PLA just to test them out. They worked great. I decided PETG might be better as the gates will sit out in the sun most of the summer. The PETG did not print as well. The PLA was a perfect fit over the 3/4" PVC pipe, the PETG is too tight. I can't even force it on the PVC. I am also able to peel of some of the bottom strands of PETG where it was on the bed. Almost like it did not adhere well.

Any thoughts on how to correct (I was using the recommended nozzle temps and had 55C on the bed)
 

jhitesma

Some guy in the desert
Mentor
PETG is a lot trickier to get dialed in - but once you get it dialed in it tends to print just as well if not better than PLA for me.

Different brands of PETG can be wildly different in my experience so it's hard to give exact tips. PETG likes to string and swell more than PLA but with the right temp and speed it should print nice. I've had some that liked hot and slow and some that liked hot and fast. You may also have to adjust your extrusion multiplier. I like to do single wall tests for that and make sure the wall is the thickness I have my slider setup to generate based on the nozzle size I'm using. With PETG I find even if I have an accurate filament size set I usually have to have a very small extrusion multiplier dialing things back just a bit.

My first spool of PETG print quality was all over the place as I learned what I was doing. Higher quality PETG helps too. I've mostly used MakerGeeks and Atomic. The MakerGeeks works well but is fussier to get dialed in, the Atomic printed great with a wider range of settings.

I printed my whole MPCNC in a mix of the MG and Atomic filaments. This was the Atomic Gunmetal grey:
20160403_203619.jpg


Not my best print quality ever - but I only did 2 quick test prints dialing the filament in before letting it rip. And the MPCNC is now getting close to 3 years old and I haven't had any failed parts despite fairly regular usage and occasional exposure to high temperatures when I forget to leave the AC on low in my shop when I'm not in it.