[adidoro]

Does every motor on your machine have it's own power supply? If not, is your X and Y on the same power supply? (If yes you may not have enough current for two motors running at the same time)
Or maybe your speed is to high for what your CNC can handle, try and lower the feed speed and acceleration.
Could be many reasons to lose steps...

[blazo]

Yes every motor have it's own supply.

Mach3 Motor tuning
x, y axis steps 320 vel.1000 acceler. 100
z axis steps 320 vel. 600 acceler 30
I check the axis travel and is correct.
Tray with exacts stop (like in youtube)

Tray change the axis on the stepper controller.
Tray change steps and acceler.
Tray change microsteps and steps/rev on stepper driver


Today I enabled the z axis in config Ports & pins and maybe you don’t believe but the circle was perfect no missing steps on circular path.
I really don’t know ….