Z_TILT for 4 stepper_z

[DrumClock]

@Sineos

Have you tried reducing the number of probed points to 3, e.g. first one at Z1, 2nd one at Z2 and third one between Z3 and Z4?
Not sure but from looking at the function it seems to try calculating a plane and then determining the adjustment needed for “balancing” this plane.
Calculating a plane from 4 points seems like a bad idea.

Do you mean to use 4 steppers_z but scan only 3 points?

[DrumClock]

I tried it now and it works.

[z_tilt]
z_positions:
 17.23
 17,263
 257,263
 257.23

points:
 63.70
 63,265
 263,195

[DrumClock]

That doesn’t work either, if the difference between the steppers is greater, it will also be interrupted by the error “Retries aborting: Probed points range is increasing.”

[LifeOfBrian]

I have 4 Z steppers on my Micron+ and it works fine using QGL.
For testing purposes you can use set_kinematic_position and then change whole Z to check whether all Z steppers drive into the same direction.
Furthermore my own experience shows that wrong coordinates of joint and probing points can/will cause increasing tolerances.

@Sineos has a nice drawing and article regarding to those understanding and measurements.

[DrumClock]

@LifeOfBrian

For testing purposes you can use set_kinematic_position and then change whole Z to check whether all Z steppers drive into the same direction.

Hi, I keep repeating here that the position and direction of rotation of the Z stepper is correct.

I see that 4 Z steppers are complicated, so I will go to 3.
This will be sufficient to level the ground BED 8mm thick with flatness tolerance ± 0.100 mm.

Let me know if there is anything else I should try. Otherwise I will definitely redo it.

Thanks to all.

[LifeOfBrian]

My triple-Z CoreXY mostly needs one tilting round to get below the set tolerance but if everything is correct even 4 Z motors work fine.
As I wrote it is essential for the algorithm to have correct positions of the respective joints and probing points.
Even the probe itself can influence that when it is too much at the edge of the bed or after homing its position does not really match the declared probing points…
But this applies to triple-Z as well.

[DrumClock]

Hi, I precisely measured the psition for [z_tilt] and made the adjust.

Configuration of 4 stepper Z and 3 measuring points.

I noticed that when probing there are positive and negative measurements
in the same position.

What does that mean?

Retries: 2/5 Probed points range: 0.001250 tolerance: 0.010000

Making the following Z adjustments:
stepper_z =  -0.000888
stepper_z1 = -0.001773
stepper_z2 = -0.000361
stepper_z3 =  0.000525

probe at 250.000,70.000  is z=  0.000877
probe at 250.000,70.000  is z= -0.000373

probe at 160.000,265.000 is z= -0.000373
probe at 160.000,265.000 is z= -0.001623

probe at 40.000,70.000   is z=  0.003377
probe at 40.000,70.000   is z= -0.005373

-------------------------------------------------------------------------

Retries: 3/5 Probed points range: 0.005000 tolerance: 0.010000

Making the following Z adjustments:
stepper_z =  -0.000266
stepper_z1 = -0.001360
stepper_z2 = -0.007080
stepper_z3 = -0.005986

probe at 250.000,70.000 is z= -0.005328
probe at 250.000,70.000 is z= -0.005328

probe at 160.000,265.000 is z= -0.002828
probe at 160.000,265.000 is z= -0.005328

probe at 40.000,70.000 is z=  0.003422
probe at 40.000,70.000 is z= -0.004078

-------------------------------------------------------------------------

Retries: 2/5 Probed points range: 0.012500 tolerance: 0.010000

Making the following Z adjustments:
stepper_z =  -0.004139
stepper_z1 =  0.006964
stepper_z2 = -0.002318
stepper_z3 = -0.013422

probe at 250.000,70.000 is z= -0.011023
probe at 250.000,70.000 is z= -0.011023

probe at 160.000,265.000 is z= 0.002727
probe at 160.000,265.000 is z= 0.000227

probe at 40.000,70.000 is z=  0.001477
probe at 40.000,70.000 is z= -0.007273

-------------------------------------------------------------------------

Retries: 1/5 Probed points range: 0.011250 tolerance: 0.010000

Making the following Z adjustments:
stepper_z =  -0.011477
stepper_z1 = -0.005116
stepper_z2 =  0.007023
stepper_z3 =  0.000662

probe at 250.000,70.000 is z=  0.000331
probe at 250.000,70.000 is z= -0.000919

probe at 160.000,265.000 is z=  0.001581
probe at 160.000,265.000 is z= -0.000919

probe at 40.000,70.000 is z= -0.005919
probe at 40.000,70.000 is z= -0.015919

-------------------------------------------------------------------------

Retries: 0/5 Probed points range: 0.014375 tolerance: 0.010000

Making the following Z adjustments:
stepper_z =  -0.114689
stepper_z1 = -0.129081
stepper_z2 = -0.121937
stepper_z3 = -0.107545

probe at 250.000,70.000 is z= -0.110000
probe at 250.000,70.000 is z= -0.110000

probe at 160.000,265.000 is z= -0.123750
probe at 160.000,265.000 is z= -0.125000

probe at 40.000,70.000 is z= -0.115000
probe at 40.000,70.000 is z= -0.117500

[EddyMI3D]

@DrumClock

What does that mean?

This is within the accuracy of the probe.

[DrumClock]

@LifeOfBrian

@Sineos has a nice drawing and article regarding to those understanding and measurements.

Hi @Sineos can you please send it to me?

Thanks

[LifeOfBrian]

Check this:

Understanding X and Y Axes Limits and Homing

The X and Y Axis Klipper needs to know from its printer.cfg settings how far the X and Y axes can safely move without hitting the printer’s frame. It also needs to know where the origin (X=0 / Y=0) is. This origin is the beginning of the usable printer bed. In the following, we assume a Cartesian printer that follows the conventions of a Cartesian Coordinate System. This is also the reason why it is a quasi-standard to define the origin as the left-front corner of the bed. This way, all logic…

[DrumClock]

Hi, just a question. Is it better if there is a probe or a nozzle above the “pivot point”? Because the probe has an XY offset from the nozzle