[pdsherathia]

i have a 3 axis cnc wood router
when i start spindle motor the step motor also start random rotation and axis moves unnecessarily with large noise and vibration
probably this may be due to loading effect of spindle motor on stepper drive
or may be loading on driver controller card.
but what is probable solution of this problem??
pls help

[Al_The_Man]

Most often grounding and/or bonding problem, make sure the spindle frame is grounded properly.
http://www.cnczone.com/forums/phase-...se-issues.html
http://www.automation.siemens.com/do.../emv_r.pdf?p=1
Al.

[James Newton]

EMF. As Al says, grounding is key. Also make sure your step and direction cable is good quality (fat wires), short, and away from everything else. Shielding, even rapping a ground wire around the step-direction wires, is a last resort.