Hemera gears gripping / slipping
Got my Hemera unit installed about two weeks ago [early batch I guess, still stamped Hermes] and nicely dialed in, initially worked great for short prints. Started a longer print which started failing about 5 hours in, with the gears seemingly gripping at a regular rate producing under-extrusion and bumps. Reducing tension on the idler produces slipping with underextrusion, increasing tension increases gripping (tried adjusting the tension so that the white tab is flush with the lever as was suggested to someone with a similar issue, no improvement).
I’ve got retract at 0.25mm, 20mm/sec, so doubt it is the cause. Seems to be speed related, as first few layers and top/bottom layers (20-25mm/s) seem unaffected, whereas infill and walls higher up (50mm/s) are. Manually feeding or withdrawing filament goes easy, there does not seem to be a clog, but asking Octoprint to extrude straight filament produces the same phenomenon. Was about to disassemble the whole thing but with the current mount I have it’ll take a while so I figured I’d hit the support wiki first. Anyone has that issue and, ideally, a solution?
For reference, my printer is the following:
CR-10S, mainboard changed to SKR v1.3 running TMC2209s
Klipper firmware; pressure advance disabled to see if the problem would improve (it didn’t). Played around with extruder stepper current to no avail (but shouldn’t be the issue as the gears should not be gripping).
Is this a good question?