hnmc20
commented
3 years ago Maybe the drivers experience brownouts during printing that reset their settings? Does it happen on all the drivers at the same time?_
- I don't know if it's a brownout issue. I'd have to monitor the power to tell if there's a power glitch.
Does it happen on all the drivers at the same time?
- The SKR mini uses UART to scale down the current from the +- 1.8A set by the Rs, and when it happens if you run the M122 you'll see that the scaling factor went all the way up, so someway something changes the register. UART glitch? If you check trinamic's layout example, BTT does not follow the VS filtering, capacitors... anyway, hard to tell what is going on.
Yes, I would have expected from a "mini" board made for ender type machines, to target a lower current range. It would yield better dynamic range for control and less burnt coils.
- I think they wanted to cover all possible uses, just pushed beyond the recommended and the PCB copper they used does not allow the necessary heat dissipation (mini v1.2) they seem to have beefed it up on the v2.0 though.
I purchased this board while it was sold out and received it in late october of the new batch 1.2s
I installed it as I followed the instructions. After a few days with the new board It sounded as if my z motor was binding. I went to work adjusting it to be as smooth as possible. 3 days later I just tried running the motor without the lead screw. Still was making the grinding/binding sounds. I swapped our my Z and my y motors. initially the swapped motor sounder better but not good. and then I tried moving X and Y and Extruder, all were making grinding type sounds. My initial research made me think that I might have unplugged the z motor while live blowing the driver (I dont recall doing this but it's possible as I kept trying different solutions. But this doesn't explain why all the motors would be making noises now. I was only making adjustments to Z.
I swapped back in the OEM board and everything moved but it wasn't smooth or quiet or accurate. Something fried the motors in the 2-3 days after installing the board.
This was confiered today when I bought 1 new motor and moved it around the printer to hear the difference on each point. sounded like a cement mixer before and the normal stepper hum after in all 4 positions.. So I THINK something fried on the board but i KNOW my stepper motors are all fried.