"Grant Erwin" wrote in message
...
jtaylor wrote:

In my head I have a kind of picture how a rotary table might be made.

You have a base, with a central pivot (could be bored for a taper).
Around
the pivot is a gear & the table, driven by a worm.

Some of these tables are advertised to have a method by which the table
can
be decoupled from the gear, to allow quick rotation without turning the
worm. I have been turning this picture around and around in my head and
cannot figure out how they do this.

Someone tell me or point to a drawing, please...



The worm is mounted on a shaft which is cammed so that rotating the shaft
causes
the worm's center to move away from the gear's center, effectively
disengaging
it. This is a very desirable feature on RTs and in my opinion a must have.

GWE

Aha.

There'd have to be some method of adjusting the position of the worm in the
cam (or the bearing surfaces of the worm) then.