To avoid confusion "spindles = Stair spindles", may be called other things in other countries
So as an example I want to make a round "Candle stick" with a shapely body.
Assuming ( always risky
) the "A" axis is aligned along the "X" axis
Generate the Gcode to drive "X" along the axis and "Z" axis to generate the required shape , (perhaps digitize an existing shape if you wanted a copy)
I mount the stock in the chuck of the "A" axis, load an appropriate cutter in the M/C collet, probably a 2mm tapered ball point
I start the "A" azis at a constant low speed ,( perhaps 2 rpm), run the prog. which runs the "X" axis slowly along ( perhas 200 mm/min) while the "Z" axis (aligned on the centre line) cuts the profile.
Ideally would be able to control the rotary axis similar to the M3/M4 commands, so that speeds and feeds could be controlled from within the prog, two modes selectable (normal - constant)
I have used this method but with a seperately driven rotary axis, it works very well but a built in mode would be much more convenient and controllable
I have a Luthier friend who has used this method (also wih a seperately driven axis) to cut pegs for guitars, if you dont have a CNC lathe it allows to produce identical parts