4 motors on one axis homing
I building a laser engraver with Duet3 + Duet 3 Expansion board 3HC
I have 2 motors on X (both motors moves one X belt), 4 Motors on Y (two motors moves left Y belt, two motors moves right Y belt) and 2 on Z (8mm lead screw).
Can I use sensorless homing in case of 2 motor moving same belt?
what will the Homeall file look like in this case?
Do I need to change motors mapping?
M569 P0.0 S1 ; physical drive 0.0 goes forwards
M569 P0.1 S1 ; physical drive 0.1 goes forwards
M569 P0.4 S1 ; physical drive 0.5 goes forwards
M569 P0.2 S1 ; physical drive 0.2 goes forwards
M569 P0.3 S1 ; physical drive 0.3 goes forwards
M569 P1.0 S1 ; physical drive 1.0 goes forwards
M569 P1.1 S1 ; physical drive 1.1 goes forwards
M569 P1.2 S1 ; physical drive 1.2 goes forwards
M584 X0.2:1.2 Y0.0:0.3:0.4:1.0 Z0.1:1.1 ; set drive mapping
M350 X16 Y16 Z16 I1 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z400.00 ; set steps per mm
M566 X600.00 Y600.00 Z100 set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z200.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z60.00 ; set accelerations (mm/s^2)
M906 X1200 Y2400 Z1200 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout
; Axis Limits
M208 X0 Y0 Z0 S1 ; set axis minima
M208 X300 Y680 Z120 S0 ; set axis maxima
Using endstops to home is pretty easy in RRF3.
Using sensorless homing is also straightforward. Just define the sensorless endstop type and it will take care of the rest. Home the axis as normal. Though you will have to tune the stall detection settings, and long belt runs and multiple motors might make that a bit harder.
Endstop switches really not an option?
I probably can place endstops for the Y axis. But for X and Z it will be almost impossible.
For sensorless homing should I use both motors pulling one belt or just one of them?
@phaedrux any idea if sensorless homing should use both motors pulling one belt or just one of them?
o_lampe last edited by
How would you use only one motor? Turning down the motorcurrent works per axis and is the same for all motors AFAIK.
fcwilt last edited by
Why multiple motors on a single belt?
in this case endstop detection will be considered at a stall detection from the first of the two motors if they do not stall simultaneously? Or do both motors need stall detection to trigger the endstop?
Heavy X axis with Z axis mounted on it.
taking into account the low cost of the steppers, and 6+3 driver on Duet3 + 3HC I decide to put 2 motors for 1 belt and thereby reduce the backlash and increase the torque. Which is especially important for high accelerations of a heavy head. And I plan to put a spindle in addition to the print head to be able to finish the surface after printing and drilling holes
o_lampe last edited by o_lampe