Re: [CAD_CAM_EDM_DRO] Re: Is this too nuts to consider ?

If the groove can be cut in one pass, you might consider rigging a cable
to the back side of the spindle wrapped around a drum, out and around a
pulley, then attach to the carraige.
This would be a crude adaptation of something I read in HSM years ago to
cut very long tapers. The writer fixed one end of the cable to the bed
and the other to a drum on the cross feed screw that was sized
appropriately. Under power feed, the cable would unwind and advance the
cross slide. Dia must be calculated at drum dia + cable dia, less approx
2% or so for tension on the cable reducing that slightly.
This idea would work sort of in reverse, and I think you might have
trouble getting it to repeat for a second pass. But if you could do it
with a single pass and form tool, it might work.

Jon