Driver overvoltage and stall

Esteban

Hello,

I've just encountered a problem on my Duet 3 mini 5+ motherboard. Unfortunately, the direction of my Y axis was reversed during standard homing. This inversion caused the platter to physically stop against the machine's chassi and the stepper motor to stall for a few seconds (the time it took for me to cut the power supply).
After powering up again, my Y axis only vibrated without really moving forward. I know that this is often a bad sign, but on principle I reinstalled all the programs and updates without succeeding in solving my problem.

So I have two questions:
Can stalling for a few seconds destroy a driver?

I'd also like to know what the best solution is for protecting my drivers (Duet 3 mini 5+ -> TCM2209). I think there's already some protection in the chip, but it's often too weak.
Could adding a zener diode (in one direction for phases A+ and B+ and in the other direction for phases A- and B-) be a solution?
If so, is the output voltage of the drivers 5V or V_in?

Thanks in advance for your help

Esteban

@Esteban
Can installing an end-of-course max stop prevent this kind of problem or will the movement be proiritory on the stop? If not, will the stops remain active when the M564 S1H0 command is sent?

dc42

@Esteban stalling a motor does not damage the driver.

if the motor just vibrates when you try to move it then the likely causes are:

Bad connection in one of the motor wires. In this case, if the motor current is set to more than 500mA by M906 then you will usually see a message such as "Driver [N] phase A[P] may be disconnected" in Duet Web Control, where N is the driver number and P s the motor phase (A or B).
Blown stepper driver. Again, you may see a message in DWC.
Blown stepper motor. This is rare. Again, you may see a message like "Driver n phase A may be disconnected" in Duet Web Control.

You can also run M122 and look at the Driver Status reports.

Esteban

@dc42
Thank you for your reply,
On my M122 order I don't get any error on my drivers. So I looked at other motors and also the continuity of my lines and everything seems correct. On the other hand, what seems strange to me is that I only had one motor connected to my Mini 2 expansion card and neither of the two drivers is working. When I damage a driver, for example by making one of my axes move too fast, should I only damage one driver?

dc42

@Esteban yes that does seem odd. When you run M122 do drivers 5 and 6 show up in the Move section, or are they flagged as not present?

In theory you could forcefully move the motors by hand so fast as to create an over-voltage condition that could blow multiple drivers both on the main board and the 2-driver daughterboard; but I doubt that you would be able to move them that fast.