MK3S+ Temperature calibration is way off.
I've been having a heck of a time printing PETG properly. Always seems to have problems that seem temperature related, even though I've been print hotter than recommended. I've noticed that my printer just seems to print a little better when run higher. The problem is really apparent when using pre-sliced code. If I don't stand there and manually adjust the temperature and keep an eye on it, PETG prints will just fail. Trying to solve a bridging issue, I printed the PETG smart temp tower, and it broke down at 225*, blobbed and knocked over the print. That should not have happened, so I figured there must be something wrong with the temp reading.
I got the thermal probe for my Klein Tools multimeter (so not some rinky-dink amazon special) and checked the nozzle and the bed. The thermal probe is rated max 230*C. so I set the nozzle to 215 & the bed to 100. When I checked the readings, I could not believe my eyes. The heatblock & nozzle were reading between 185-190 depending on location, and the bed read 90* in the center and 70* on the edge. This is ridiculous. 20-30* off? No wonder nothing sticks to the bed and I can't get my prints to work.
Looked through the calibration and settings menu, and there are no correction factors for the thermal probes. I imagine the error is probably a curve rather than linear, but if I could at least bump the hotend up 25* and the bed 10* that should get me close enough that my prints will start working.
Is there any means of correcting the readings inside the printer?