On Mon, 13 Feb 2006 10:59:32 -0400, "jtaylor"
wrote:


"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.

Ayup..this also allows you to take out any backlash.

Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3