Burned Z axis pin on board.
As the title says, a pin on my z motor connector on the board burned a bit today and let some delish smoke out right by my face.
The board has been working. Just after i jogged the z axis up the motor powered off. Kinda hard not to notice 8 inches away. Good thing i have thermal camera for my phone.
So this is what it looks like warmed up doing some print moves for 8 or so hours
This is just less than 3 minutes of being on, as you can see the board is cold except where the z axis drive is, no other drivers were warm yet.
So all in all not sure if the board is safe to use anymore.
With the Z motor disconnected, does the Z driver chip get hot?
The motor was always plugged in, the thermal image shows its much warmer than the cold board that was maybe on for a few minutes max.
I suspect one of the following:
1. A bad crimp connection to the pin that got burned. This would account for why only one pin shows signs of overheating. It may also have led to failure of the Z driver.
2. A short in either the motor or the wiring to it, either between the phases, or a short to ground from the wire that of burned. A short to ground would explain why only one of the pins burned.
3. It's possible that root cause was a faulty Z driver; but that doesn't explain why only one of the pins burned.
I don't see an issue with the crimped wire shown in the picture, but you can see there is some burning from a arc. The driver does'nt have a blow hole like the others did.
I'm still in the testing and setup phase on the printer so that could be it, but its been working for a few weeks with no problem.
I'll have a look at the wires from the board to the motor, The motor is a nema23 running on 1050Ma any lower it loses steps.
Would a thermal video of the board powering on help? ill try to get the motor wires and board in the shot
I don't think a thermal video would help. I think the most important things for you to do now are:
1. Check for a short to ground or to the stepper motor casing from the wire that got burned.
2. Check whether the Z driver gets hot, when Z movement is commanded but no Z motor is connected. If so then the Z driver has failed. Assuming you are running either current stable firmware (1.19.2) or a 1.20 beta, you should also get error messages if the driver is overheating or has a shorted mosfet
Which M code gets the error codes again?
M122 produces a diagnostic report. However, if you are running firmware 1.19.2 or later, you don't need to run M122 because error messages will be generated if overheating or a short to ground is detected.
alright sounds good im running 1.20Beta11 so it should be good
So if the Z driver remains cool when you command Z movement (to enable the driver and set the current) with no Z motor connected, then the driver chip may still be OK. Check the Z motor and wiring for shorts, re-make that connection, and try again.
Everything thing checks out, no grounding of any coils, the driver stays cool.
No shorts found I had a electrical engineer look over it he came up the same thing.
Thermal made it obvious that it's not warming up at all.
So I'll re-pin the wires and test some more
Ok after all that. It turns out the driver doesn't drive the Z properly skips steps and has no tourqe . Swapping in the x axis driver it works great at a lower current.
Also hooked up a scope she's a noisy one.
I dont think the fault was my doing, but ive been wrong before. So what to do?
David what can we do about this?
If your Duet is still under warranty, email your supplier.
It's probably not as this will be the second time a driver has failed and the third board to shit it self.
Overall this is giving me a bad taste, what are my options if my warranty is over? I haven't even done a single print with the thing.
I received my replacement in September so does that mean its under warranty ?