Re: [CAD_CAM_EDM_DRO] Converting a rotary table

I bought a 6" Chinese rotary table with the idea of using it as the fourth
axis on my mill. What I found was that the worm wheel is not concentric with
the table's bearing. The engagement of the worm is adjustable on an
eccentric but the end result is that the table is tight to turn at one point
and has some backlash at another point. If the backlash is adjusted out the
table may be impossible to turn at the tight spot.

I made a mounting sleeve to fit the body of the rotary table and put a servo
motor on the other end of the sleeve. Joined the motor and table shafts with
a coupling. The motor drove the table OK but with backlash. If I adjusted
the backlash out the motor could not turn the table. I scrapped this
attempt. However, I think it would work with a good quality table.

If you are going to do this make sure that the table will turn smoothly
without backlash. This is hard to do in the shop becuase you will need tools
to adjust the backlash out.

Dave.

----- Original Message -----
From: "Andrey Lipavsky" <alipavsky@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Wednesday, July 27, 2005 11:05 PM
Subject: [CAD_CAM_EDM_DRO] Converting a rotary table


> Have any of you converted one of the "Little Machine Shop" rotary tables
and
> would be inclined to share your experience and/or advice? I scanned
through
> the files section but nothing jumped out at me.
>
> Thanks,
> Andrey