Sir Thank you for the response, I have said I believe my problem is motor vs mass vs velocity, I counterbalanced mass which helped, I played with accel and vel settings and it helped however my 20 min job went to 40 min, not acceptable. I accept that motor control with encoder is not a option and have moved on to plan B of building a new Z axis that can be removed quickly allowing me to use mill in as designed and the new Z can be attached to a dedicated machine I designed just for these projects. I have asked about encoder control only as a possible band aid to the real problem. Since I have had a crash course about steppers, drivers, Gcode, Mach 3 and retroing my machine in the last 5 months, all responses have reaffirmed my confidence in my basic skills. I still would like to see a screen with stepper Dro and encoder Dro on same page as I am a visual person and am always going to play and push the limits I would like to see a problem when a job might be salvageable, this brings me to a point, at 55 I know that I do not understand everything I know, so I have a question for you. You state watch my bandwidth, now I am lost. Sir if you would please expand on where I would watch my bandwidth in Mach3 ? JD