Quote Originally Posted by malcolmd View Post
Hi Clive. Of course your right. Ok. I built it myself, it has an mdf and timber table and has no earth, never thought of that, the rest is steel and aluminium, ball screws and hiwin rails. 4 nema 34 motors, 2 on x-axis and 1-y, 1-z, all motors are belt to ball screw driven, my break out board is an HG08 and stepper drivers CW8060 all from cnc4you, i get ''external ratio requested even when I reference all home, spindle or not, last night it said limit switch triggered but it hadn't, very frustrating, not sure what else to tell you
What does this mean (external ratio requested)? What controller are you using? Have you tried cutting in air above the table with out the spindle on?

Your symptom sound like EMF (noise) have you use a star point for all your grounds? some good pictures of the inside of the control box would help.

Please be specific with what you have done and give answers to the above.