(John Flanagan) wrote in
:

Dear All:

I've got a part I need to machine (repeatedly) and was wondering if
anyone might make a suggestion for an effective and inexpensive
method. A photo of the cut that needs to be made can be found he

http://vulcan.blacksburg.net/~flanag...al%20Sleeve%20
RFS.jpg

You can see the collar on the upper right part has been cut ~90°.
I've been thinking of using a 5C collect in one of those cheap spin
indexers you can get at ENCO for ~$30. The collar is less than .250"
thick by ~ 1" wide, material is silicon bronze. I'm a little
concerned about controlling the part as I spin it by hand since the
spin of the indexer is direct without gears and can (I think) move
freely front to back while spinning). A photo of the spin indexer can
be seen here;

http://www.use-enco.com/CGI/INSRIT?PMAKA=235-6011

The only other solution the I can think of, for a professional looking
finish at least, would be to use a $$$ super spacer or to buy a chuck
to mount on my rotary table with the 3MT center (which has it's own
problems of set up time and PITA factor).

John,

I've machine loads of parts using a spin indexer in just that way. I used
to work at a company that made bayonette lock connectors. I used to
hollow mill the posts then mill the remaining material away using a 5C
indexer. The forces are low, and if you go slow and controlled it's quite
safe.

We had a Hardinge indexer and you could set it so it would stop at the
right degree. Plus it has a lever for indexing which probably would have
a better "feel" than the handle on the back. But there is no reason the
Enco one won't work.

Using this method you will still get a radius in the surface of the part
where you are milling the shoulder away.

If you want a nice blended surface, consider making or buying a form
cutter with the radius of the part ground into it. Think of a key cutter
with the radius of the part ground into the teeth.


--

Dan