I've bought a batch of 42BYGHM810 steppers a while ago and I was pretty happy with their behavior.
But over a few working hours they seem to cause problems. It feels, like they've lost the permanent magnetism which causes missing steps. I even blamed my diamond hotend to be partially clogged, but now I think it's the steppers.
I have one unused stepper and compared it with the used ones:
When I shortcut black/green and red/blue coils and turn the shaft by hand, I can feel much more resistance with the new one.
But over a few working hours they seem to cause problems. It feels, like they've lost the permanent magnetism which causes missing steps. I even blamed my diamond hotend to be partially clogged, but now I think it's the steppers.
I have one unused stepper and compared it with the used ones:
When I shortcut black/green and red/blue coils and turn the shaft by hand, I can feel much more resistance with the new one.