Actually the second. If I had a million dollars I would hire a full
time patent attorney and file.

I have an old CC lathe built in 1977 and the 3 jaw runs out about
.002. Unacceptable for gear box work. What is worse is adjusting a 4
jaw to zero the run out. So I combined some of the features of the 4
jaw and the 3 jaw. This is an adjustable backing plate adapter.

Besides that the locating bore in the back of the 3 jaw was not even
round.

This is located on the OD of the chuck which in this case 6.25
inches roughly. Probably metric. It matters not if the OD of the
chuck runs out as well. Once it is locked down you have a super
accurate 3 jaw.

There are four 10-32 set screws that do the adjusting then the chuck
is locked down with three 8 mm screws. 32 threads per inch is far
better than the adjusting barrels on the four jaw which are about 6
threads per inch.

The one inch thick CR steel round was bought from Industrial Metals
in Sun Valley for $37.

It takes days to machine this. One of the problems with my lathe is
the cross slide feed is only in one thou increments. (.001)  To build
a near zero run out  adapter one needs 1/10 th thousands feed.
(.0001)

Paul Lamar

Paul, you're too late on that one - Adjustable back plates for 3-Jaw
chucks have been around for at least 60 years and probably much
longer - I had a couple of that type of adjustable back plate chucks
back when I had my own tool and die shop -

Roland Friestad

Damn! How come I did not hear about it.  I never saw an add.

I am half done.

Another problem is I searched high and low for a new back plate
that would fit. No luck so far.

-------------------------------------------------------------------------------
Good Morning Paul,

I am not having any luck finding spindle information for your machine, even with my own IPad.  My only suggestion is to try to use that measurement guide that I sent or to see if you can find a manual.  Other than that, you may have to contact a local machine shop.  Hopefully someone can come in a measure it for you.

I wish I could have been more helpful.

Kathy ColonyImage result for patriotic clip art images


One Hardinge Drive

Elmira, NY 14903

Tel 800-228-2825

Fax 607 398-7998

info@buckchuck.com


thanks kathy

Paul

On 12/02/2016 01:45 PM, Kathryn Colony wrote:

   Hi Paul,


   I’ve done some digging and so far I’m coming up empty.  I am blocked from checking quite a few sites at work though.  I’ll bring my IPad next week and see what I can find there.


   Have a good weekend and I’ll get in touch on Monday.

   Kathy ColonyImage result for patriotic clip art images

   One Hardinge Drive

   Elmira, NY 14903

   Tel 800-228-2825

   Fax 607 398-7998

   The lathe is a King  Model  LAM350B Made in 01/11/77

   Paul

   On 12/02/2016 12:16 PM, Kathryn Colony wrote:

       Hi Paul,


       Unfortunately we have to have the full information.  On page 6 of our catalog, which I believe you have seen, there is a 2-3/8-6 option which would be 6 threads per inch but it is not available as a standard adapter plate.


       I have one more option to try.  What is the make and model of your machine and I can look up the spindle specs?
       Kathy ColonyImage result for patriotic clip art images

       It about 6 0r 7 threads per inch.

       Paul


Paul Lamar

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