Z_TILT_ADJUST Command Not Level Enough

General Discussion
1

Basic Information:

Printer Model: MakerTech ProForge 3.5
MCU / Printerboard: BTT v2
klippy.log Where do I find this file?

pi@mainsail:~/work_directory $ cp /tmp/klippy.log .
cp: cannot stat ‘/tmp/klippy.log’: No such file or directory

Describe your issue:

The Proforge 3.5 printer is a coreXY printer with 4 Z-motors and a 300 X 300 bed…
I have poor first layer performance. I have run the Z_TILT_ADJUST routine and the Bed_Mesh routine with 9 x 9 probe points several times but I cannot get a 1st layer to stick that is bigger than 100 X 100mm.
I have run the Z_TILT_ADJUST routine several times and the the 4 probe points never are less than 250um apart in Z.

Does anyone have an idea how to make it better?
…

2

https://www.klipper3d.org/Config_Reference.html#z_tilt
You can reduce your retry_tolerance but it is more likely that you are suffering from a location bias. This means your extrusion profiles / design have a skew / are twisted which is leading to a non linear effect between probed point and nozzle tip.
See Probe calibration - Klipper documentation

3

Hi, I have gone through all of the probe calibrations and tried to look for twist in the X-axis. I cannot find any problems that would cause 1mm of error in the Z-axis. Do you have any tests that would measure skew or twist?

4

I have removed the _Z3 stepper motor in the PRINTER.CFG file. I mechanically removed the 4th Z lead screw, nut, and mount from the Z-gantry.

Here is the Z_TILT section of my PRINTER.CFG file:

[z_tilt]
z_positions:
 -68, 7
 -68, 365
 375, 365
points:
 -10, -5
 -10, 230
 225, 110
speed: 150
horizontal_move_z: 5
retries: 0
retry_tolerance: 0.025

I heated the extruders and base for 15 minutes then:

I ran Z_TILT_ADJUST 3 times in sequence and observed the Move screen data on the Printer. I watched until the second reading of the Z axis was close to 5.00mm for each location.
Location 1 2 3
Z Height 5.00 5.00 5.09

I then manually measured the Z- height at 5 positions on the base plate. I would move Z up and down until the probe would activate then record the Z-axis position.
L-F L-R R-R R-F Center
X, Y X, Y X, Y X, Y X, Y
-10, -5 -10, 230 240, 230 240, -5 110, 115

Z 1.29 2.19 1.29 0.890 0.690

Do you have any ideas as to why these Z measurements are so far off?

5

Here is my Klippy.dat file.
logs-202334-23244.zip (98.2 KB)