Re: [CAD_CAM_EDM_DRO] 4th axis rotary table - suggestions?

David,

The turntable you reference there is not designed for machining, though
it would likely work well for light machining.
If you get a rotary table, find one that allows you to disengage the
worm. For manual use, this allows large rotary movement very quickly.
For you, with some tinkering, this will allow adjustment of the lash, to
some extent. These have the worm shaft in a cartridge that is eccentric
to the hole. I've taken a couple apart, and while I don't recall how
they were adjusted, I recall that I could adjust them to the point they
got tight. Ideally you want to be able to play with this adjustment
before buying. What you would like to be able to do is get as tight as
possible while making full turns, and check for runout in the worm wheel
which shows up as a tight spot. If you can find one that doesn't display
a tight spot, grab it!

A decent choice is a Hardinge dividing head. I lucked out and bought one
when a local mold shop was closed by it's absentee owners. They charged
the sole remaining employee with selling off the shop. He wasn't happy
about it, and knew me, so I bagged a $1000 dividing head for $100. It's
a rare score, but I can mount a 6" chuck and run stock through the
spindle, or use 5C collets. You can also set it at an angle, something
that would be more difficult with the traditional rotary table setup.
Mine is going to be the basis of the 4th axis on my mill.