Huge temperature fluctuations related to the print fan
I have a problem with temperature fluctuations while printing PETG. The temperature is very inconsistent, it fluctuates +-15°C and sometimes even spikes to 280°C. I can't ignore that, even though my prints come out well. I noticed that the temperature starts fluctuating at layer 3, which is the layer the print fan turns on. Therefore, I think the fluctuations have something to do with the print fan. I tried using a silicone sock, but that changed absolutely nothing. When printing PLA I don't experience this issue. I print PETG at 250°C and PLA at 215°C. The other difference is the speed of the print fan. For PETG it runs on 30%-50% speed. For PLA it is always running at full speed.
Is it possible that my print fan is broken or not working properly? And if not, what can I do to solve this issue?
Thank you for all your help!
Best Answer by JSchwieb:
I almost lost my mind troubleshooting this exact same issue on a brand new board, brand new thermistor, heater cart, and part cooling fan. Support told me this morning to try a beta firmware and it fixed my issue - https://github.com/prusa3d/Prusa-Firmware/releases/tag/v3.12.0-BETA1
I was printing CF Nylon which caused huge issues if the temp went up 15 degrees because it would hit max temp and my print would fail.
RE: Huge temperature fluctuations related to the print fan
I almost lost my mind troubleshooting this exact same issue on a brand new board, brand new thermistor, heater cart, and part cooling fan. Support told me this morning to try a beta firmware and it fixed my issue - https://github.com/prusa3d/Prusa-Firmware/releases/tag/v3.12.0-BETA1
I was printing CF Nylon which caused huge issues if the temp went up 15 degrees because it would hit max temp and my print would fail.
RE: Huge temperature fluctuations related to the print fan
I flashed the beta firmware and calibrated the thermal model. It seems to have fixed the problem for me too. I'm very happy I didn't have to replace any parts on the printer. Thank you very much!
RE:
Adding my own experience to this thread: On my freshly built MK3S+ I had one second or less temp spikes of +8-12C varying between every couple of minutes to 2-3 in a row 10 seconds apart when printing PETG at 245C or 250C. It did not appear to affect quality too much, except the occasional brown glob of stuck PETG released and onto the print, which may or may not be related. PETG is just a lot stickier than PLA.
Support recommended the BETA release above, which I flashed, and then connected Pronterface to run the auto temperature tuning - it does not yet have an LCD menu item. After this, all temp spikes went away. I think the amount of carbonized PETG deposits on my prints was reduced as well. Highly recommended update.
EDITED: what software is used to get a temp chart like above?
RE: Huge temperature fluctuations related to the print fan
EDITED: what software is used to get a temp chart like above?
OctoPrint
If at first you don't succeed, skydiving is not for you.
Find out why this is pinned in the general section!
RE: Huge temperature fluctuations related to the print fan
OctoPrint
I should have figured.. If only a Raspberry Pi was available for purchase anywhere.
RE: Huge temperature fluctuations related to the print fan
Im having these same exact issues printing PETG with two new builds I just put together this past week. My two older MK3s's dont have this issue at all. I didnt think the beta firmware would help but after reading this, Ill be flashing it today.
OctoPrint
I should have figured.. If only a Raspberry Pi was available for purchase anywhere.
n808 I found a super easy to follow script to install octopi on a ubuntu pc, and its working perfectly. super easy to set up and is a great way to use an old PC. we dont need no stinking overpriced pi! 🙂
RE: Huge temperature fluctuations related to the print fan
I almost lost my mind troubleshooting this exact same issue on a brand new board, brand new thermistor, heater cart, and part cooling fan. Support told me this morning to try a beta firmware and it fixed my issue - https://github.com/prusa3d/Prusa-Firmware/releases/tag/v3.12.0-BETA1
I was printing CF Nylon which caused huge issues if the temp went up 15 degrees because it would hit max temp and my print would fail.
Thank you!
I saw the same situation as OP with my brand new MK3S+. Seemed fine with PLA but when I switched to PETG I was seeing +-15 swings.
Prints seemed fine and the jumps seemed too large to be a real temp change but rather a sensor issue.
Installed the beta firmware, reran PID calibration, ran the new temp calibration, and the current print is holding so far at +1/-2.