Extruder Motor Skipping Steps When Hot

[jluvs2ride]

Voron 2.4 R2 Built from a FormBot Kit.

This has been driving me nuts, but I think I've finally narrowed this down to the extruder.

I believe the extruder motor is skipping steps when it gets hot. I can print smaller items OK but printing a model that uses the whole bed just gets wrecked. It may or may not lay down a perfect first layer but at some subsequent point the extruder starts clicking and the print just goes to crap.

Any thoughts?

 

[5twenty]

Is that PETG?

 

[5twenty]

Sorry, meant to add more...

Is it enclosed?

Is there a clog? (you may not see it, feel it, or notice it whatsoever - it could be some foreign matter like a bug!! seriously:

https://www.reddit.com/r/3Dprinting/comments/r3v4pm/my_filament_has_a_bug_leg_in_it

<<<< just one of many I've seen out there)

Those aside, it sounds like a thermistor issue. I've had faulty ones, mostly on Revos, that will super-heat the filament, then cool off, leaving burnt residue within the column/path. When it cools after this, there is no amount of heat that the hotend can apply, that will remelt it - IME.

If this is enclosed, and the thermistor is good, which it does not sound like it is, you are getting too hot. It doesn't look as if it is, so check and make sure the thermistor is good. Search "testing 3d thermistor"