You could probably correct the loose/tight from one side to the other
problem, Jim.

The horizontal RT I bought used, had a couple of snug spots as the table
made a full rotation, I was able to get a completely uniform engagement by
gently scraping a couple of "gear teeth" spaces.
Then the entire rotation was silky smooth with essentially zero backlash. No
perceptible backlash can be felt by trying to force the table by hand,
anyway.

I bought a set of plates a while back, and yourself and a few others
answered my questions regarding the number of holes and the potential
applications.
I will definitely need to refer to Machinerys Handbook to be able to use
them with any degree of confidence.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Jim Wilkins" wrote in message
...
On Mar 31, 12:51 pm, "Wild_Bill" wrote:

In addition to disengaging the worm, there should also be a screw to
adjust/limit the engagement of the worm. With this adjustable stop screw,
the amount of worm engagement can be adjusted so that each time the worm
is
re-engaged, it stops just short of dragging or binding. When properly
adjusted, backlash is non-existent or at least minimal......
--
WB

It doesn't quite work on mine, when tight on one side there is
backlash on the other, as though the 40 tooth gear isn't quite
centered on its bearings.

Some have graduated degree wheels, others a set of index plates which
are more precise and easier to use when you need to index some large
number of identical spaces, like cutting a gear. I think the degree
wheel might be easier to figure out if you had to rotate by one large
angle, such as making a plate cam or a smooth curve between protruding
arms, like this:
http://picasaweb.google.com/KB1DAL/T...75471032901730
Either way, they are tricky to use unless you are comfortable with
math and geometry.

Jim Wilkins