Hello guys,

1) When no step pulse inputs and motor is in stationary, it will have small vibration sound emitting out and small ossicalation. These occurs every time to time after a short period of time interval around 2 minute.
2) I attach a dial indicator stylus tip on the its y-axis moving block, it is set to zero. The Linux cnc screen y-axis digital output also at zero. I slightly step it forward and backward but I also use my hand to add the reaction force to the moving block prevent it from moving. After a couples of times of these actions, when stepping back the digital output to zero, the dial indicator already went to a couples of divisions away from zero (at 0.04mm). Were there already losing steps. Or, are the leadscrew axle coupler or pinion or pulley were not firmly fixed on the axles and have the slippery... As they are hidden and I have not yet checked.
3) When the machine cut a circular block, the y-axis direction has severe dimensional error, 29mm became 28.2mm.
4) I don't think there is any backlash on the leadscrew and ballnut as it is brand new and is NSK brand..
5) Voltage supply to the drive is from transform 80VDC, by DC-DC buck step down convertor to 45VDC, there is also 10000uF capacitor for smoothing the voltage ripples.
6) On the drive, the micro step is set to 1600 pulse/rev. I haven't done any factory setting inside the drive such as PID setting etc.
7) Will there is some wrong lead wires connection of servo feedback or some loosen connections?

Anyone who have idea what mistakes I commit are welcome for the recommendation, thanks