I have a Bridgeport J Head mill that I converted to a cnc. Installed ball screws on the x, y and z. I doubled checked my calibration on all axis and all is good.

I am using the Masso G3 Touch with these stepper motors, https://www.automationtechnologiesin...sbridgeportkit

Well every time I try to bore a hole in aluminum or steel it does not come out as a circle more like a freehand circle.

Since then I replaced my spindle bearings, shimmed my x and y gibs. I haven't looked at my knee gib yet.
I tried just doing hole boring after I did all the above with no luck.

I am running the spindle at 2720 rpm with a 8mm end mill and using a mister for lube and air.

Is there anything I could try or look at?

Thank you for the help, Nathan