David, Everybody,
thank-you for the interest in the RF CNC project.
I've shamelessly copied a design from YouTube driving the axes leaving the handwheels in place. With the stepper drivers switched on – you can't move them by hand. Drivers off – you feel the steppers cogging over giving slight resistance to motion. The X&Y leadscrews are replaced with ballscrews which would rotate under axial load without that resistance. I'm told that the steppers probably generate backEMF which may not be good for drivers , i haven't had problems.
photos are probably self-explanatory
The Z acts on the quill. The original quill rack-and-pinion mechanism gives more backlash than i'm happy with.
Controller is GRBL running on Arduino – works very reliably – I am impressed.
Arduino step-and-direction output goes to hefty drivers bought with the stepper motors from cnc4you – works fine – photo shows all the bits – subsequently moved to proper enclosure-
In use for 5 years for shape-simple and shape-complex machining.
hope that's helpful,
johns




Edited By John Scott 13 on 27/09/2021 12:39:06