Easy Servo Drive?

[JAZZCNC]

One reason I like the idea of servo steppers is because I find the machine sometimes loose steps when pocketing circles. When it goes to the centre it needs to change direction really fast to keep constant velocity. It then loses position slightly. My current solution is to slow the feed part way through the operation as it nears the centre, but at the moment that means manual g-code edit for me. I might also want to machine a whole sheet of detailed nested parts and then finish off with the through cuts so vacuum is maintained until the final cuts, but doing so much work across the sheet and then eventually coming back to the first part I find I may be out of position very slightly.

Well you have under powered steppers or are overtuned if loosing steps or position.(or some mechanical issue) The closed loop system won't help in this case all it will do is fault rather than carry on out of position. Under powered or Overtuned it will be just same closed loop or not and Only way around this is correctly sized steppers or tune motors correctly.

My machine cuts Ali for 10hrs + with deep DOC at High feeds and still comes exactly back to where it started.
Like today it did a 4hr job with multiple tool changes and straight after a 2.5hr job with 5 tool changes. The last operation was a Finish pass on some pocket walls with smaller dia tool to clear out the corners etc. If I'd lost just few micro steps this would have shown on the pocket floors. And this was after 6.5hrs straight cutting Ali with at times high feed trochoidal toolpaths with 20mm DOC using 8mm cutter, 15 toolchanges and 200+ drilled holes.

So what I'm saying is Closed loop won't help a badly setup or under powered machine.! Or make it anymore accurate than a correctly setup plain vanilla stepper machine.