Extruder Temperature Control Erratic

[christophercombo]

Hello Community,

Just wondering if anything can help me troubleshoot some problems that I've been having with my MakerGear M2 (w/ the V3b hotend). I have been printing perfectly fine for a few years and only in the last two print attempts did this issue arise.

In this image, you can see the extruder temperature set point (dotted red line) and the actually temperature measured by the temperature transmitter. I'm trying to control the extruder temperature at 215C but its bouncing all over the place.



Any help would be appreciated!

Thanks,

Chris

[ednisley]

printing perfectly fine for a few years

Over those years, the thermistor in the hot end has gradually broken down. Order a replacement, install it, and the temperature will snap right into alignment again.

It's possible there's a failing wire between the thermistor and the RAMBo, but that's not the usual problem. You can try wiggling & jiggling along the cable while watching the temperature graph: if it changes erratically, your fingers are on the problem.

Don't change anything else until you replace the thermistor, because you'll just un-change it afterward.

[christophercombo]

Thanks for the reply. I'll order it right away.

Chris

[jk42]

Try heating up your hotend to printer temperature. If the temperature is consistent, move the extruder assembly back and forth by hand. If you get those large temperature fluctuations the problem is probably your extruder harness.