Pressure Advance + Calibration Cube = MCU Shutdown

General Discussion
1

MCU Shutdown when printing calibration cube with PA. Seen this same topic as a bug on git issues but that was in 2020.
Model is a simple cube 30x30x25 (WxLxH) in vase mode with extrusion width 0.45mm sliced in superslicer. Tried multiple times with different settings but always shuts down right after finishing first layer and about to start second.
Tried with lowering retraction and retraction speed to 0.1mm and 20mm/s. Any idea what else to change to get it to print properly?
klippy.zip (529.7 KB)
Edit: Added gcode file
Settings 4 (23m) - PETG - 0.2mm.zip (24.9 KB)

2

Just tried with no PA, but MCU Shutdown still occurs at same place
No PA klippy.log (247.9 KB)
No PA (23m) - PETG - 0.2mm.zip (23.9 KB)

3

Your attached log reveals:

Transition to shutdown state: MCU 'mcu' shutdown: Rescheduled timer in the past
This generally occurs when the micro-controller has been
requested to step at a rate higher than it is capable of
obtaining.

Since there is no further information on this printer:

  • Either you are very experienced in Klipper and know exactly what you are doing or you copy / pasted each and every macro / setting you came across
  • There are a lot of safety overrides that are not typically needed / recommended
  • Your run_current settings are very low for X and Y axis
  • All these driver_ should be carefully used as they depend on exactly the driver / stepper combination and their technical spezifications
  • The sense_resistor do not match what TMC2130 typically have
  • It has a very low end MCU, but your accel settings and microstepping should be in a sane range

My recommendation is to start with a fresh base configuration for your printer and then slowly extend it with functions / settings that are needed and understood.

4

The printer is a Prusa Mk3S with a Bondtech BMG extruder. Settings are just a patchwork frankenstein of various ones I found.
Does the log show if there is a specific G1 that is causing the error, so I can narrow it down to an axis (X,Y,E)?

5

Hard to tell. I would assume it is the extruder.
When does the error happen? During your printing setup, i.e. start gcode or already into the model?

IIRC, the printer uses an Einsy Rambo board. My reccomendation still is to start with a minimal config to avoid any interference from the other frankenstein parts.
Also see klipper/generic-einsy-rambo.cfg at master · Klipper3d/klipper · GitHub

6

Started from scratch again and found out how they got the values for the frankenstein. It was the values pulled from the prusa FW. 0.22 on sense resistor turns out to be correct according to marlin fw page.

Also solved the issue, turns out I shouldn’t have used the default prusa printer settings to build my klipper printer profile. They had M92 E0.0 before layer change that I didn’t take out, it tried to extrude a whole layers worth in 1 move. Prints fine now, but now I understand more about my frankenstein.

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