Under extruding after switching from PLA to PETG
Hey All I am having issues going from PLA to PETG both using Prusa brand filament. I had this kind of issue around 7 months ago. I was printing fine with PLA went to PETG and printed fine with a couple prints, then went back to PLA and had the issue of under extruding around an hour into the print the extruder gears would lock up and start clicking. I changed the PTFE tube out and right as rain and continued printing with PLA since then. I now have a project that needs PETG to be used and this same issue has arisen.
I tried this suggestion from Steam Labs to push the hot end up a little more and thought that would help but it did not. I have also tried cold pulls and hot pulls to no change.
I have ordered more PTFE tubes but while I wait for them to come in, any other help would be greatly appreciated. Also sorry if this question has been answered somewhere else.
I have included pictures of the PETG print and the Benchy I just tried to run. Also when doing the first layer calibration I am getting some ripples not sure what this means either.
RE: Under extruding after switching from PLA to PETG
What has worked for me is when going from a hotter material such as ASA to a cooler material such as PETG is to load the cooler material but tell the printer you are loading the hotter material. Then extrude some filament until the color changes, then extrude some more. Unload and reload with the correct temperature. This pushes out any old high temperature filament. If you just load the low temp filament, the temperature may not be enough to push out the last of the high temperature filament.
I also change the PTFE tubes and sometimes do a cold pull similar to above, use the cooler temp material but heat it to the high temperature before the cold pull and push some of the filament through the hot end manually.
Regards,
Mark
RE: Under extruding after switching from PLA to PETG
Thanks for the reply! I have tried setting the nozzle to 270 and doing cold pulls. I have also set the nozzle to 270 and pocked the needle into it and trying to clear out anything like that. I also received the new PTFE tubes today. I replaced it and am having the same issues with what looks to be under extrusion. I have included a picture of the rippling I am seeing in the first layer calibration that transcribes into the actual print like the benchy above.
RE: Under extruding after switching from PLA to PETG
Not sure I can help much with the whole PETG side of things, but I had some under extrusion issues with different PLA brands recently. If you are interested this is the thread that fixed mine. Good luck with getting this resolved!
RE: Under extruding after switching from PLA to PETG
have you removed the ptfe tube to see if there is anything in its way
Please help me out by downloading a model it's free and easy but really helps me out https://www.printables.com/@Hello_474427/models
RE:
If you already change the PTFE tube inside the heatbreak but the issue still there, you might want to re-apply the thermal paste on the heatbreak. Here the sample at step 16