I have the same problem with my edge x. I don't think it's the motor. I have a direkt motorbolt, and a spare motorbolt, both in perfect condition, and when I plugged them into the edge x, I got the same noise- likewise, the motorbolt that came with the edge x works perfect in the direkt. What I think is the problem is a design flaw in the edge series of machines themselves. The housing that the slider mechanism is chambered in is pressure fitted to also doubles at the other end as the collet vise( where you put your tube) Too much pressure while twist the collet vise tight slightly rotates the whole housing out of place, which knocks the slider out of place and out of perfect alignment with the cam.