Kirk:
I agree, mine is a hybrid, a rotary flat table from ebay with a chuck pressfit into the center hole.
Almost anything will work since there is very little torque demand form a rotary table..
That particula
r module was a necessity as its about the only way to really make a timing pulley of any depth.
While its possible to come up with a strategy to do timing pulleys with normal bits.. its a bit of a bitch so Id rather
have the freedom to tell someone, " just make a toolbit..
the pulley is simple to make after that.. "

I have more modules in planning, we'll see what comes next. The good thing for me about GM, is that it does what
its supposed to do, so I dont feel pressure on any particula
r idea, their all gravy to users, so I can work on what interests me
and go at my own pace.
Ill let you all know what it is I decide for the next module to be done..but it wont require a 4th axis.

Art