I have built my own cnc router. I am using Nema 23 425oz stepper motors run from mach 3. My issue is I can not get the axis's to move smoothly. Every thing jogs nice and smooth but as soon as I run the roadrunner program that is sent with the mach 3 software. The machine jerks and the motors have like a humming sound. I know that I can tune the motor in mach 3 but there is something that is not right. Anyone with any Ideas?