Quote Originally Posted by Kitwn View Post
The VFD cable is screened, earthed at the VFD and connected to the spindle body. Just writing that makes me wonder if there's an earth-loop because of that. Must try removing the spindle from it's bracket.
That would be my first move. It's a much debated thing but I never ground both ends and I never have issues with these cheap sensors. Thou like voice coil mentions I cut the shitty cable off close to the sensor and use screened back to the board and ground it.