We have ONA EDM machine which controller has been defected, we have built a new controller for it using micro-controller, we adjust the gap for ranges from 0.3 mm to 0.02 mm, and apply voltage but there is no any sparks.
If control machine to continue till contact work-piece, there is a spark, but the output product is very rough.
we are using copper as electrode and kerosene as dielectric.
Thanks in advance.