[Hdogg81]

Hello all,

I have been having issues with my Mk3/4 (4 axis). Every time I turn the spindle on the controller disconnects. Any suggestions?

[tantemay]

Bad USB cable.

[PlanetCNC]

All symptoms that you described earlier are indicating problems caused by a electromagnetic interference:
https://en.wikipedia.org/wiki/Electromagnetic_interference


This occurrence interferes with the USB communication, which as a results drops and communication between controller and PC is terminated.


You see, electro motors, VFDs etc...are sources of EMI and therefore your wiring and other devices should be properly shielded and filtered. You would need to use shielded cables and use line filters for VFD. Also controller needs to use external power supply for its stable operation.
http://planet-cnc.com/wp-content/uploads/2016/03/CNCUSBControllerMk3.pdf (page 32)