Warning: motor phase A may be disconnected reported by driver(s

rogerz79

I have a duet 2 wifi board. I lost my sd card and had to start over. During the process of starting over there was a miscommunication between DWC and my board for the heaters and the way that was resolved was by upgrading to firmware 3.3. I also have a dual Z setup with each one connected to its own driver. Before I added the M671 command to my config file I was not getting any warnings and was able to home my system. No prints since yet since upgrading to 3.3. Once I added he M67 command I began to get warnings when ever the Z axis was used.

12/9/2021, 3:56:47 PM G28
Warning: motor phase A may be disconnected reported by driver(s) 2 4
Warning: motor phase B may be disconnected reported by driver(s) 2 4

12/9/2021, 3:57:00 PM Warning: motor phase A may be disconnected reported by driver(s) 4
Warning: motor phase B may be disconnected reported by driver(s) 4

12/9/2021, 3:57:05 PM Warning: motor phase A may be disconnected reported by driver(s) 4
Warning: motor phase B may be disconnected reported by driver(s) 4

Everything moves as I would expected to move. The z axis still works but I get the warning. Before I lost my SD card and was running on 2.03 firmware I was able to use dual Z axis Just fine with out an warning. I have checked the wiring and everything looks good. Left Z motor is on Z1 and right z motor is on Z2. What do the warnings mean?

; Configuration file for Duet WiFi (firmware version 3.3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.3.10 on Sun Dec 05 2021 22:24:46 GMT-0500 (Eastern Standard Time)

; General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"Ender 3XL" ; set printer name
M918 P1 E4 F2000000 ; configure direct-connect display

; Network
M552 S1 ; enable network
M586 P0 S1 ; enable HTTP
M586 P1 S1 ; enable FTP
M586 P2 S1 ; enable Telnet

; Drives
M569 P0 S0 ; physical drive 0 goes backwards
M569 P1 S0 ; physical drive 1 goes backwards
M569 P2 S1 ; physical drive 2 goes forwards
M569 P3 S1 ; physical drive 3 goes FOWARDS
M584 X0 Y1 Z2:4 E3 ; set drive mapping
M671 X-16:390 Y0:0 ; leadscrews at left (connected to Z) and right (connected to E1) of X axis
M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z400.00 E394.79 ; set steps per mm
M566 X1200.00 Y1200.00 Z24.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X9000.00 Y9000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
M201 X200.00 Y200.00 Z100.00 E250.00 ; set accelerations (mm/s^2)
M906 X800 Y800 Z800 E800 I50 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Axis Limits
M208 X-16 Y-1 Z0 S1 ; set axis minima
M208 X390 Y405 Z450 S0 ; set axis maxima

; Endstops
M574 X1 S1 P"xstop" ; configure switch-type (e.g. microswitch) endstop for low end on X via pin xstop
M574 Y1 S1 P"ystop" ; configure switch-type (e.g. microswitch) endstop for low end on Y via pin ystop
M574 Z1 S2 ; configure Z-probe endstop for low end on Z

; Z-Probe
M950 S0 C"exp.heater3" ; create servo pin 0 for BLTouch
M558 P9 C"^zprobe.in" H5 F120 T6000 ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-32 Y-36 Z2.5 ; set Z probe trigger value, offset and trigger height
M557 X50:350 Y50:350 S70 ; define mesh grid

; Heaters
M308 S0 P"bedtemp" Y"thermistor" T100000 B4092 ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0
M307 H0 B0 S1.00 ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0 ; map heated bed to heater 0
M143 H0 S150 ; set temperature limit for heater 0 to 150C
M308 S1 P"e0temp" Y"thermistor" T100000 B4725 C7.06e-8 ; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1
M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
M143 H1 S275 ; set temperature limit for heater 1 to 275C

; Fans
M950 F0 C"fan0" Q500 ; create fan 0 on pin fan0 and set its frequency
M106 P0 S0 ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"fan1" Q500 ; create fan 1 on pin fan1 and set its frequency
M106 P1 S1 H1 T45 ; set fan 1 value. Thermostatic control is turned on
M950 F2 C"fan2" Q500 ; create fan 2 on pin fan2 and set its frequency
M106 P2 S1 H1:0 T45 ; set fan 2 value. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 F0 ; define tool 0
G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets
G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C

; Custom settings
M501

dc42

@rogerz79 can you identify the type of the Z motors? Is it the same as the type of the X and Y motors? Do the Z motors get hot?

Some 3D printers use low current high inductance Z motors so that two can be driven in parallel from a single driver. If that's the case then you need to reduce the Z motor current in the M906 command, and perhaps also the max Z speed in the M203 command.

rogerz79

@dc42 both are "Creality 42-34(Z)" motors. They do not get hot. Their specs are
SPECIFICATIONS:
Step angle: 1.8 degrees
Steps: 200
Nominal Voltage: 4.83V
Current Rating: 1.5A
Rated speed: 1-1000rpm
Rated torque: 0.4NM
Ambient Temperature: -20 - 50℃
Length: 34mm

dc42

@rogerz79 I suggest you plug those numbers along with the phase inductance (if you can find it) into the EMF calculator at https://www.reprapfirmware.org/emf.html to see whether your 180mm/sec Z speed exceeds the full-torque speed.

rogerz79

@dc42 I have plug those numbers in to the tool. I used 8.4mh for the inductance and 5.75 for the resistance. As far as I can tell it states that anything above a 20 mm/sec will cause it to loose torque and slip. Doesn't that sound too low? Or should I be getting different motors to drive my two lead screws that are 500mm long?

Phaedrux

@rogerz79 said in Warning: motor phase A may be disconnected reported by driver(s:

20 mm/sec

20mm/sec is quite fast for a z axis. Keep in mind the difference between mm/sec and mm/min.

The creality motors aren't the greatest and don't tend to perform well outside of their intended configuration that Creality has chosen them for. There are better motors to choose from.

rogerz79

@phaedrux dropping it down to 20mm /sec does get rid of the warning