Error: motor phase A and phase B disconnected on drivers 2

Reckham

@dc42
the problem has been solved. - at least for me.

I had the same issue today:
It has been caused by wiring. I have seen that 1-2 of the 4 cables have been a little unloosen and the cable diameter had been reduced. This is why the motor hadn't had enough voltage and this caused the problem.

Check your wiring guys

madmattco

Got a single line of motor failure just now.

https://puu.sh/CrHOD/b8e12dd972.png

https://puu.sh/CrHQa/96b01477be.png

https://puu.sh/CrHRb/4b31e2f123.g

jckray

@dc42

I have also been getting this error for both phase A and B on driver 2. Please let me know if there is any information I can provide to help get this bug fixed. The exact same message is present on all 4 of our printers with the same hardware running Firmware 2.02

dc42

@madmattco and @jckray, please let me know:

Which Duet you are using;
What M906 motor current you are using on the motor(s) affected;
What motor(s) you are using;
@madmattco, please confirm that you are using firmware 2.02 release, not a RC version.

jckray

@dc42

I am using Duet WiFi V1.04
Motor current is 320
Two Z motors in series rated at .4A (https://www.omc-stepperonline.com/linear-motor/nema-17-external-34mm-stack-04a-lead-8mm031496-length-300mm-17ls13-0404e-300g.html?mfp=181-lead-screw-length-mm[300])

Could this be an issue with low current motors, especially when in series? I plan to switch to 1A Z motors eventually.

dc42

Yes, I think it's caused by using 2 low current motors in series. Try connecting them in parallel to just one of the Z motor connectors (put the 2 jumpers back in the other) and double the current.

madmattco

@dc42
I'm running a maestro.

All motors are set to 1 amp.

The motors are on an anycubic kossel linear plus. to my knowledge the specs are as follows.
Motor Type: Bipolar Stepper
Voltage Rating:3.3V DC
Rated Current/phase: 1.5A
Phase Resistance:2.2ohms ± 10% (20 C)
Step Angle: 1.8 deg.
Phase Inductance:3.8mH ± 20%(1kHz 1V rms)

I am running the 2.02beta2(RTOS) (2018-08-30b3)

dc42

Upgrade your firmware to the 2.02 release.

JohnnyBeeGood

Two weeks ago I had a shaft of a nema 17 break, so had to do some maintenance to my CoreXY.
Was finished powered the Duet Maestro on and got this message:

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

Gives it on all drivers.

So had to find where this problems was coming from, config? firmware?, wiring?, nothing worked...

So I have quite a few Maestro's had 3 from the fitforlauch campaign and had 2 whose U3 burnt out... still need to get the warranty on them.

Hooked up a new Maestro and it worked.

Two days ago on the same machine I had to rebuild the extruder, finished today and getting the same bloody error.

I am running 2.02(RTOS) Motor Currents, M906 X1200.00 Y1200.00 Z1200.00 E1200.00 I70;

dc42

I see that you've created another thread about this, so I will close this one.