G32 True bed Compensation Configuration issue

gbiski

Hello,

I have connected the 3 motors of the leadscrews as on the picture:
Bed Comp.jpg

I have as printing area X=280 and Y=300 and my config file is

584 X4 Y1 Z2:5:6 E0 ; set drive mapping test also E3
M671 X135:280:0 Y300:95:95 S2 ; leadscrews at rear center, left middle and right middle

My bed file is:

M561 ; clear any bed transform
G28 ; home
G30 P0 X150 Y290 Z-99999 ; probe near a leadscrew
G30 P1 X270 Y95 Z-99999 ; probe near a leadscrew
G30 P2 X50 Y95 Z-99999 S3 ; probe near a leadscrew and calibrate 3 motors

When I run G32 however the head is not moving to the correct coordinates

Home 140 150 This is correct
Rear probe 120 290 Should be 150 290
Right probe 240 95 Should be 270 95
Left probe 20 95 Should be 50 95

Why do I get always 30mm difference on X?
I tried also with M671 X135:300:-20 Y340:95:95 S2 in order to take into account the real position of the lead screws but in this case the head is smashing on -20 on the x axis.

Every time a perform G32 I get big corrections like the following : Is this normal ?
Corrections -1.521 -0.944 2.509

Thanks a lot for your help

Phaedrux

What firmware version?
What is your probe offset?
What is in your homeall.g?
Have you read this through? https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors