Quote Originally Posted by diycnc View Post
Not at all! Just the sticky grease they come with at he moment. Pretty sure the noise is just the motor vibration on the metal frame, not the screw. Might try taking the belt off tonight to test without any load.
This vibration could be causing resonance which will affect the performance.

However, at 5Mtr/min your close to reaching the limit and other factors will come into play so resonance could be clipping your wings a little.
Also depending on the controller then you might be better off dropping the micro-stepping. When reaching limits the controller and quality of pulses starts to play its part.

With 68V and digital drives on a machine with decent rails, aligned and set up correctly with average gantry weight of 30-50kg then I'd expect to top out around 7mtr/min with 5mm pitch. I would tune to run at 5mtr/min.