Bed leveling issue

Basic Information:

Printer Model: custom Creality Ender 3 v2 - Creality S1 direct extruder, dual Z axis (just belt driven pullyes
MCU / Printerboard: BIGTREETECH SKR Mini E3 v3.0

Describe your issue:

I have been using Klipper via KIUAH instalation on Debian Rpi 4 for two printers. I do onw Ender 3 v2 and v2 Neo. Both were running creality 1.4.4 silent MCU flawlesly. The issue starterd when I purchased the Creality S1 direct extruder and the Bigtreetech SKR Mini E3 MCU. I found the new setigns for the SKR MCU for printer.cfg update it to connect to the new board. Went over the steps for new klipper printer. Everything checked out it prints, but.
The issue is that I am unable to use G29 auto levelig tool. For some reason there is a difference between the Z-ofsett for G28 and G29. If i paper align the ofset for G28, and then run G29 the printer stratrs the print with the nozel diging through my printer bed. Then I found “probe_calibrate” I did it which changes the ofset for the result of G29 but G28 has -2,240 mm ofset from the printer bed. -

  • Aditionaly the bed mesh test cant run 2 samples becase for some reason the second test starts lower then specified 15mm in the test and thus fails.
  • Aditional problem there seems to be some memory of the mesh. Becase the bed mesh test gives me impossible results it says there is a max of -2.212 mm and min of -4.130 mm differenc of the height of the bed. If i go to Z 0mm and release the steper motors. I can move the extruder around and the height is prety much constatnt paper height. No such difference as the bed level says. I noticed while it was testing the probe that the Z axes went lover in some areas than in the others thus the difference.

Please advise, I was able to print small part with disabled G29 just with G28 in the middle of the printer bed. But at this point it is impossible for me to print anything larger .
klippy_printer3.log (1.3 MB)

Hello @Evilblack !

It appears, that the run_current for tmc2209 stepper_z is way too low.:

run_current = 0.580  # reccomended at least 800

Also max_z_accel is way too high:

max_z_accel = 1000 # recommended less than 50

Previous are the reason for:

I do appreciate the reply. I wrote this post after a month of research and trying to correct the problem. It appears that I soleved it 30 minutes ago.
The issue was in the BLtouch. I am using the original BLtouch not a copy. But for some reason it did not work properly after the change so I had to add the line “pin_up_reports_not_triggered: false”. This coused all the wird behaviour of the bed mesh discrepency and the offset of G28 Z0 and G29 Z0 offset. The root case was bad documentation from Bigtreetech for the sensor_pin: I was missing “^” infront of the pin number. After correction of the sensor pin and deleting of the pin up false it works flawlesly.

The correct setup for original BLtouch and Bigtreetech SKR E3 v3.0 is:
sensor_pin: ^PC14
control_pin: PA1

You can close the topic, hope it helps somebody with the same issue.

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  • will test the printer with the current, and change it to your recommended 800 for the next print
  • not sure why i put the 1000 for the acceleration. I probably tried to test if it manages to compensate for the height difference of the printer bed. Case I print with speed modifier 300%. But I do not need to have it that fast it worked with the slower speed as well.
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