"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"PrecisionmachinisT" fired this
volley in news:CYGdnb8eIcfaXwzMnZ2dnUVZ_hudnZ2d@scnresearch. com:

I use a VMC with the spindle locked in oriented position but the same
can be done on a lathe...


Yup... I have a one set of indexable-insert boring bars that have been
converted with custom-ground inserts into lathe keyway cutters.


http://www.ebay.com/itm/2-SQUARE-TOO...-/360657118852

But you can also take any suitable piece of shafting you've got laying
around, drill and tap the end for a setscrew, and then cross drill it to
accept a round bit that you've made out of something like an old center
drill.

--lay your 4th axis onto it's side and you can cut splines, internal (and
external) ratchets and spurs; square, hex, and octagonal socket recesses,
etc...