I came to join the ranks of those facing rattling/scratching noises from the y-axis and - while reading a good amount of posts about the community's experiences and fixes - most of which I applied to my Mk3 Kit, it seemed to me that one particular aspect of my circumstances was not mentioned yet.
Besides bearing & little play in the carriage, main source is the vibration of the stepper and subsequent resonance of the frame structure - no news here.
What strikes me is that the y-stepper motor, when energized, vibrates a fair share more than all of its other counterparts. And, ironically it even increases when switched to stealth mode. To eliminate the driver as source of error, I switched the motor connection on the board with the x axis motor, but only the original candidate showed this strange behaviour. Essentially, holding the motor in your hand, you can feel the buzzing of the motor as mild vibrations. Again, comparing with the other motors, it seems excessive. So I suppose the stepper motor might be a bit faulty. One the other hand, I have little experience with how much a stepper motor is allowed to buzz and what is considered normal. We stud me up is that it is one of five showing this and that stealth mode makes it worse.
Did anyone experience funny behaviour of a single stepper or the fact that stealth mode led to more noise?