"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:

Ig,

I've come up with a potential application that would require me to
syncronize three rotary motions simultaneously. Similar to what you did
with rigid tapping, but with a non-milling machine.

However, it seems EMC^2 might be the tool to do it.

Would you be willing to share the code/system configs you used to sync
your spindle with Z for tapping?
OK, there are probably two ways to do this. If what you are trying to do
can be expressed in the form of G-code, then EMC2 might be used generally
the way it is. But, that is mostly one of the threading cycles, like G33.
It pretty much wants to synch Z movement to the spindle.

Now, this assumes you are wanting to synch something to a motion that EMC
doesn't have precise control over, ie. a spindle. If you just want 3 rotary
axes to move in synch to each other, call them A, B and C and write the
required G-code to move them the way you want.

If you need to synchronize 3 rotary axes to some external motion, then EMC2
can't really do that directly right now with G-code. Underlying EMC2,
however, is a much more general system called HAL (hardware abstraction
layer). If you want to link 3 axes to move, as "electronic gearing" to
something else, with specified ratios and offsets, this can be done in HAL.

Jon