Core XY, Dual Z, Move One Motor?

Dizzwold

FIRMWARE_NAME: RepRapFirmware for Duet 3 MB6HC FIRMWARE_VERSION: 3.4.5 ELECTRONICS: Duet 3 MB6HC v1.01 FIRMWARE_DATE: 2022-11-30 19:35:23

Hi Guys,

I have a Modded Tronxy X5SA Pro CoreXY currently with dual Z axis motors with Duet 3 6HC.

Most often when I switch the printer On, the right hand side has dropped by around 0.2mm.

I have a macro fro when levelling the bed to raise or lower by 0.2, but is there a gcode command I can use or create a macro to move only the One motor, i.e the right motor?

In my conifg.g I have the motors setup as follows;
M584 X0.0 Y0.1 Z0.2:0.3 E121.0 ; set drive mapping

Is there G1 command I can use to move only the One Z axis motor?

As always grateful for your advice.

Dizzwold.

droftarts

@Dizzwold Split the Z into two separate axes, and move the one that needs to move. First, define the second Z axis (U) in M584 in config.g and set it to hide this additional axis using the P parameter. You will need to add parameters for the U axis (set them the same as the Z axis) for M350, M92, M566, M203, M201 and M906, eg:

M584 X0.0 Y0.1 Z0.2:0.3 U0.3 E121.0 P3          ; set drive mapping

M350 X16 Y16 Z16 U16 E16 I1                     ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z400.00 U400.00 E420.00       ; set steps per mm
M566 X900.00 Y900.00 Z60.00 U60.00 E120.00      ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z180.00 U180.00 E1200.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 U20.00 E250.00      ; set accelerations (mm/s^2)
M906 X800 Y800 Z800 U800 E800 I30               ; set motor currents (mA) and motor idle factor in per cent

To move the one axis, unhide the U axis, move it, then hide it again.

M584 P4         ; make U axis visible
G91             ; relative movements
G1 H2 U0.2 F500 ; adjust U axis
G90             ; absolute movements
M584 P3         ; Hide U axis

I think that should work. The hiding and unhiding of the U axis is important, so it doesn't accidentally get moved, and shouldn't mess with your Z homing.

Ian

Dizzwold

@droftarts

Hi Ian,

Okay, that make sense.

I'll give it a go when I tinker some more.

Thank you for the detailed reply.

Dizzwold.