Dual Z Setup - Single Motor Movement Headache
jch last edited by
I'm fairly new to Duet, so to say this was a steep learning curve, is a small understatement... . Very frustrating, but sticking with it!
Anyhow, after some exsessive reading, and trial and error (and some head banging, cause I can do it myself, yeah right), I now have succesfully homed X, and Y, and partly Z....
A little context...
My setup is a CoreXY dual Z, setup using drives 2 & 4 for independant homing, with independant endstops for both. The plan is to use the DC42 IR Probe for Auto Bed COmpensation eventually, but I need to get the homing sorted first.
I'm runing of the latest Duet Wifi with the latest firmware (2.03 (2019-06-13b2)), and have a 24v PSU to drive the lot. After the initial RRF config, I started changing the config to fit my setup, and so far so good, or so I thought.
Just for reference, this is what my config.g file looks like (so-far)
; Motor remapping for dual Z M584 X0 Y1 Z2:4 U4 E3 P3 ; Driver 0 For X, 1 for Y, Z=2:4 U=4, Extruder 3, P3=Don't show Virtual drive ; Physical Drive connection M569 P0 S1 ; Drive 0 X M569 P1 S1 ; Drive 1 Y M569 P2 S1 ; 1st z-motor (original Z) M569 P3 S1 ; Extruder0 M569 P4 S1 ; 2nd Z-motor - Normally used as Extruder 1 M350 X16 Y16 Z16:16 U16 E16 I1 ; Configure microstepping with interpolation M92 X80.00 Y80.00 Z2560.00:2560.00 U2560.00 ; Steps per mm for XY and Z2:4 +U4 M92 E420.00 ; Set steps per mm for extruder M566 X900.00 Y900.00 Z12.00:12.00 U12.00 E120.00 ; Set maximum instantaneous speed changes (mm/min) M203 X6000.00 Y6000.00 Z180.00:180.00 U180.00 E1200.00 ; Set maximum speeds (mm/min) M201 X500.00 Y500.00 Z200.00:200.00 U200.00 E250.00 ; Set accelerations (mm/s^2) M906 X1920.00 Y1920.00 Z1200.00:1200.00 U1200.00 I0 ; Motor currents (mA) and motor idle factor % for XYZ M906 E800.00 I50 ; Set extruder current (mA) and motor idle factor in % M84 S30 ; Set idle timeout ; Axis Limits M208 X0 Y0 Z0 S1 ; Set axis minima M208 X300 Y300 Z290 U290 S0 ; Set axis maxima ; Endstops M574 X1 Y2 Z2 U2 S0 ; 1=Min, 2=Max, S0=NO, S1=NC
As mentioned, homing X&Y is no great issue (although I need to sort the motor hum, which I will do later). With the inclusion of the Z axis moving when homing X & Y (move Z up/down), all appears to be ok, this is till I home Z.... this is my current homez.g file
G91 ; Relative mode;M584 Z2 ; Split Z into 2 (Z+U) G1 Z250 U250 F2000 S1 ; Move up to 250mm in the +Z direction. S1 to stop if endstop is triggered G1 Z-2 U-2 F600 S2 ; Move 2mm in the -Z direction - S2 = If containing axis letters: offset will be added to the pause coordinates G1 Z3 U3 F100 S1 ; Move slowly 3mm in the +Z direction, stopping at the homing switch M584 Z2:4 ; Join U to Z again (pay attention to drive numbers used) G1 Z-5 F3000 ; Move back again 5mm in the -Z direction G90 ; Back to absolute mode
When I come to home Z, for some strange reason, only one of the Z motors with move. Now, this is not a big deal when the the bed is close to the endstops, but when they're not, this skews the bed, and binds the motors. So much so, that I have to restart the Duet. I've swapped the motors, the cables, everythign I can think of (I think), but nothing seems to have any impact.
I must be missing something trivial somewhere, but like anything else, the more I look at it, the less I see....
ANY help would be greatly appreaciated (before I have to go off to A&E for concussion damage )
Near the start of your homez.g file you need to unhide the U axis, or else the U parameter in the G1 S1 command won't be recognised. Do this using M584 P4. Hide the U axis afterwards by adding the P3 parameter to the M584 command later on in homez.g.
jch last edited by
OMG, DC42, thank you so much!! Tired it, and ureka. Homing Z!!