[Solved] Multiple independent Z motors and Motor current

Veti

Hi

I set up 2 z motors for the bed leveling using using
M584 X0 Y1 Z2:4 ; Two Z motors connected to driver outputs 2 and 4

However i realized that the Z4 Motor was getting a lot hotter than the Z2 Motor.
The current was configured
M906 X1200 Y1200 Z800 E1200 I30

But it seems that the Z800 only applies to Z2 and not Z4
I had to issue
M906 X1200 Y1200 Z800 E1200:800 I30
and now Z4 stays cool as well.

is this intended behaviour? as it not what i would have expected.

dc42

The entry for M584 on the GCodes wiki page states that you must put the M584 command earlier in config.g than several other commands, including M906.

Veti

thanks dc

but the command is before the others
; Drives
M584 X0 Y1 Z2:4 ; Two Z motors connected to driver outputs 2 and 4
M569 P0 S0 ; Drive 0 goes backwards
M569 P1 S0 ; Drive 1 goes backwards
M569 P2 S0 ; Drive 2 goes backwards
M569 P3 S0 ; Drive 3 goes backwards
M569 P4 S0 ; Drive 4 goes backwards (Z2 in the E1)
M569 P0 V118 ; Stealthchop2 till about 78 mm/sec
M569 P1 V118 ; Stealthchop2 till about 78 mm/sec
M569 P2 V118 ; Stealthchop2 till about 78 mm/sec
M569 P3 D2 ; Extruder in Spreadcyle
M569 P4 V118 ; Stealthchop2 till about 78 mm/sec
M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation
M92 X80 Y80 Z1600 E414 ; Set steps per mm
M566 X900 Y900 Z12 E240 ; Set maximum instantaneous speed changes (mm/min)
M203 X18000 Y18000 Z180 E3000 ; Set maximum speeds (mm/min)
M201 X3000 Y3000 Z250 E10000 ; Set accelerations (mm/s^2)
M906 X1200 Y1200 Z800 E1200 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout
M671 X-75:295 Y110:110 S0.5 ; leadscrews at mid left, and mid right

Issuing M906 Produces
Motor current (mA) - X:1200, Y:1200, Z:800, E:1200:1200:1200:1200, idle factor 30%
So the second Z is at 1200 mA.

samlogan87

Don’t you need to set the current, speeds, accelerations, jerk and steps per mm for the other axis by assigning it to a different axis. I think the next one is U. There is a section about setting up multi z axis and it explains it there. I can post an excerpt from my config file when I get back to my computer it a couple of hours. I am running 4 z motors

dc42

See the part of https://duet3d.dozuki.com/Wiki/Gcode#Section_M584_Set_drive_mapping that is emphasized in bold text.

samlogan87

@Veti

Here is an excerpt from my config. This is when I was running the three z axis motors

; Drives

M569 P0 S1 ; Drive 0 goes forwards X Axis
M569 P1 S0 ; Drive 1 goes forwards Y Axis
M569 P2 S0 ; Drive 2 goes forwards Z Axis FL
M569 P3 S1 ; Drive 3 goes forwards Z Axis RC
M569 P4 S0 ; Drive 4 goes forwards Z Axis FR
M569 P5 S1 ; Drive 5 goes forwards Extruder

; Motor remapping for dual Z

M584 X0 Y1 Z2:3:4 U3 V4 E5 P5 ; Driver 0 For X, 1 for Y, Z=2:3:4 U3 V4, Extruder 5
M350 X16 Y16 Z16:16:16 U16 V16 I1 ; Configure microstepping with interpolation
M350 E8 ; Set Extruder to 8x Microstepping with no interpolation
M92 X80 Y80 Z400:400:400 U400 V400 E1900 ; Set steps per mm 2149.14
M566 X60 Y60 Z20:20:20 U20 V20 E6 ; Set maximum instantaneous speed changes (mm/min)
M203 X10000 Y10000 Z800:800:800 U800 V800 E3600 ; Set maximum speeds (mm/min)
M201 X3000 Y3000 Z250:250:250 U250 V250 E120 ; Set accelerations (mm/s^2)
M906 X1000 Y1000 Z1850:1850:1850 U1850 V1850 E600 I75 ; Set motor currents (mA) and motor idle factor in %
M84 S30 ; Set idle timeout

You will see that I had to put the U and V values in for each axis as in theory they are another axis that is then bound with the M584 command.

Veti

@samlogan87

thanks sam.

that also looks like a workaround like mine.
what is your output of the M906 command?

Scachi

@veti Aren't you missing to explicitly assign the motor of your extruder / E:3 in your M584 command, to remove the 4 from its default assignment ?

https://duet3d.dozuki.com/Wiki/Gcode#Section_M584_Set_drive_mapping
Assigning a drive using M584 does not remove its old assignment. Therefore, if you assign a drive that defaults to being an extruder drive, you should also assign the extruder drives explicitly as in the above example. Failure to do so may result in unexpected behaviour.

samlogan87

Hi @Veti

My M906 command is there

Regards,
Sam

Veti

@scachi

thanks that was it.

dc42

@veti said in Multiple independent Z motors and Motor current:

@scachi

thanks that was it.

...which is why there is that bold text in the description of M584 on the GCodes wiki page.

Veti

yes sometimes you need another pair of eyes to double check your config