Based on the limited information you provided, I'd say you have a wiring issue. Please have a look at the info here: docs:blackbox:faq-identify-motor-coils [OpenBuilds Documentation]
well I have all the wiring correct , it runs the axis smooth, I'm using the post processor GRBL Plasma, the axis when free from stepper drag are smooth, with stepper drag are smooth only jerks when runs the g code file the art is from corel and sent to sheetcam in the shape of a 3in hart then post processed.
the jerk happens along the long side of the heart and the same at the top and just as it finishes the cut, and the relay will not fire by it self i have to fire it first the it will fire the relay when i run the program
Does it happen when cutting a square (or anything that doesnt have an arc)? If not, then its probably how sheetcam converts arcs into a lot of line segments. In Fusion, there is a option for "smoothing". Not sure about sheetcam but it might be worth asking on their forums. There are others on here with more experience on plasma machines that will probably chime in. It Friday night though so might not here anything right away.
sounds like backlash to me, nothing wrong with the Gcode so if the machine is not moving smoothly is is probably a mechanical problem.