Bed leveling with 3 independent z screws

mundsen

2 z screws on the left side and one on the right side + BlTouch running Duet3

Anyone want to share settings for this?

Status today (railcore inspired printer) :
All axis ok
X and y limit switch ok

Waiting for the tool board for the extruder.. wires

BlTouch ok

PaulHew

Hi.
Sounds like this is similar to a RailCore.

This what we use for levelling.
M140 S75 ; Raise bed temp to profile requested bed temp
M104 S150 T0 ; Raise hot-end temp to 150C for G32 auto-calibration
M190 S75 ; Wait for bed temp to rise
M109 S150 T0 ; Wait for hot-end temp to rise to 150C
G28 ; home all axes
G32 ; Autocalibrate bed
G32 ; Autocalibrate bed a second time
G32 ; And a third time ( for 4 point probe)

HTH
Paul.

PaulHew

You also need to make sure your leadscrew locations are defined.
P.

PaulHew

My Bad! Forgot to say we use this in our slicer config!
If you look at https://railcore.org/software/ there are base configs for the Duet2.

P.

Danal

I have a very slightly different setup, two "in front" and one in "Center back". I believe you can update this fairly easily.

Relevant statements extracted from config.g:

; Driver to axis mapping
M584 X0 Y1 U2 Z3:4:5        ; X and Y for CoreXY.  U for toolchanger lock. Z has three drivers for kinematic bed suspension. 
M569 P3 S0                  ; Drive 3 direction | Front Left Z
M569 P4 S0                  ; Drive 4 direction | Front Right Z
M569 P5 S0                  ; Drive 5 direction | Back Z
; Leadscrew locations (really, kinematic coupling locations) extracted from CAD model assuming back right build plate corner is (0, 0)
M671 X300:5:152.5 Y316:316:-14 S10 ; Front Left: (300, 316) | Front Right: (5, 316) | Back: (-14, 152.5)
M350 Z16 I1                       ; Set 16x microstepping for axes. Use interpolation.
M906 X2500 Y2500 Z1000 E1250 I30        ; Motor currents (mA) and Idle percentage
M201 X600 Y600 Z10 E1000 U1000          ; Accelerations (mm/s^2)
M203 X25000 Y25000 Z400 E4000 U10000    ; Maximum speeds (mm/min)
M566 X700 Y700 Z2 E3000 U200          ; Maximum jerk speeds mm/minute
M92 Z3200                               ; Steps/mm for Z - TR8*4 / 0.9 deg stepper

And bed.g (note that front left is a little offset in Y because of a temporary thing that blocks that corner of the bed):

G0     X152.5 Y40 H1 F10000
G30 P0 X152.5 Y40 Z-99999       ; probe near back leadscrew
G0     X275   Y260 H1 F10000
G30 P1 X275   Y260 Z-99999      ; probe near front left leadscrew
G0     X25    Y315 H1 F10000
G30 P2 X25    Y315 Z-99999 S3   ; probe near front right leadscrew and calibrate 3 motors
G1     X0     Y0 F10000