Solved 4 independent z axis tilt

[bilsch]

I'm trying to understand how to configure for my voron 2.4. This is using duet3 vs klipper

So I'm having an odd issue. Its easiest to explain via https://youtu.be/-1k2hf2g6po. The config is sorta stolen / tweaked. The last bit really is this

The gist of the video is that the 4 corners are not equal distance from the frame extrusion its all crooked ;(

When following https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors#Section_Example_for_3_motors its not clear to me how to draw the visual in my head for what each of the coordinates means. Where, if anywhere, does order come into play?

For example in my configuration:

; Drives for Z - verified locations
M569 P0.2 S1                                       	; Front left 
M569 P0.1 S0                                       	; Back left
M569 P0.0 S1                                       	; Back right
M569 P0.3 S1                                       	; Front right
(...)
M584 X0.4 Y0.5 Z0.0:0.1:0.2:0.3 E1.0               	; set drive mapping
(...)
M671 X354:354:-53:-53 Y0:370:370:0 S20        	 	; Define Z belts locations (Front_Left, Back_Left, Back_Right, Front_Right)

I don't understand what those numbers mean and how I need to make the measurements / fill it in. Am I just measuring the distance from the belt center to the corner or something? I'm just not following what the doc is trying to tell me to do!

[fcwilt]

@bilsch

Consider your M584 command:

M584 ..... Z0:1:2:3

That specifies your four steppers. Those fours steppers are presumably positioned near the four corners of the bed.

Now consider this M671 command:

M671 X a; b; c; d; Y e; f; g; h (I had to use ; instead of : because the : triggers special characters such as which is a colon followed by a b - don't ask me why it does this.)

The a and the e specify the XY "position" of the first Z stepper in the M584. The position is relative to X=0, Y=0 where ever that may be, perhaps the front left corner of the bed or, in my case, the center of the bed.

Likewise the b and the f specify the XY "position" of the second Z stepper.

And so forth.

This way the firmware knows which Z stepper to adjust to move a given corner of the bed.

Strictly speaking you want to specify the XY positions where the bed is actually being lifted by the steppers.

So let's say X = 0, Y = 0 is the left front corner of the bed. And that the Z stepper is located at X = -50, Y = -50 but the part that is moved by the stepper to lift the bed actually touches the bed at X = 20, Y = 20.

So in the M671 you would use the 20, 20 not the -50, -50.

Make sense?

Frederick

[bilsch]

@fcwilt said in 4 independent z axis tilt:

M671

Ok yea I think I'm getting this now thanks! I also found https://www.mrappz.com/voron-electronics-setup-i/ - going to let this churn a bit and see where it goes thanks!

Bill

[bilsch]

@fcwilt Ok confirmed yea this is exactly what I needed thanks!