I have a Vortech CNC Router and am running Mach 3 my problem is when I'm cutting curves or large radius I get a lot of chatter, it's almost as if the steppers are fighting each other. Not sure  if that makes any senses. If anyone as had a problem like this or has any ideas I'm open for suggestions
 

Show us a bit of the gcode that is giving you problems.  Is it a million little segments that make up the arc? That's been trouble for me before.

This is a file we attempted on Saturday, code created by Vectric VCarve.  Just a simple circle in box.

It is not only slow, but the gantry trembles like the steppers are fighting.

Steve.

It looks that your postprocessor is spitting zilion lines for simulating arcs.
Change your post to "Mach2/3 Arcs (inch)"

Second, Switch off Exact Stop mode.

Thanks, I'll try that and let you know if it works.