Mill with auxilarry spindle

PCW wrote:

To combine both position mode (for A Axis use) and velocity mode (for spindle use)
is fairly complicated. I think it can be done with one stepgen in velocity mode
but requires a PID component and a bunch of signal re-routing depending on mode.

Here is a picture:

wiki.linuxcnc.org/cgi-bin/wiki.pl?SpindleOrient

Note that is showing the config for a VFD, but the principle is very similar for a velocity-mode stepgen.