Most chucks come with hardened jaws and grinding jaws is a bitch, even after
you dissassemble the chuck, clean it all as best you can, reassemble it,
your grinding job will only be as good as your (probably well used) scroll
is, and I it's STILL going to come out bell mouthed.

As has been suggested, turn this into a paper weight and buy a new chuck.
Honestly 10 years ago my neighbor tried to fix a skanked out old 3 jaw,
after a weeks worth of work (and grinding dust all over his lathe) it was
still crap. I convinced him to buy a Bison from ENCO and he's been a happy
camper ever since. FWIW he made his own "tru-set" back for it... it's not
that hard to do, he just used an overside backing plate, turned down an
inner area for the chuck and drilled and tapped 4 #6 set screws in edge that
was left to push the chuck around.. I though it was a clever idea.

Since everyone is bragging about how they do %90 of their work I'll weigh in
on that to.

Back when I had my import lathe I got a chuck style collet closer for it,
it wouldn't mount any other kind of thru the spindle closer. Best thing I
ever did.

When I got the 5914, first thing I did was mount a Royal lever action closer
on it... I do %99 of my work with the full set of 5C's I have.. even square
and hex... Once you get a lever action closer you'll wonder how you ever
survived without one..

I brake out the genuine 8 inch Buck tru-adjust 3 jaw if I need something
bigger than 1 inch... and if I need the accuracy down to .0005 I can adjust
it.

I use my 8 inch Southbend 4 jaw for eccentric work.

Once in a blue moon I put on the 12 inch face plate for something really big
and wierd.

I'd NEVER... EVER.... grab an end mill or drill bit in a 3 jaw, you are
asking for trouble... no matter how good you think your jaws are they are no
where near parallel when it comes to grabbing a hardened tool shank... I
wouldn't think twice about sticking one in a 5C though...

--.- Dave


"Den" wrote in message
...
I looking for some advice on how to improve my lathes 3 jaw chuck.

Without going out to the workshop to measure it, it's about 7" or 8"
diameter. The jaws are worn and when small diameter work is fitted it is
a off centre by ~0.020". Looking at the jaws I can see where they are
flogged out a little, particulary the outermost 10mm or so.

I occaisionally stick a drill bit or endmill cutter in the chuck and clamp
some work in a vertical mounted vice on the cross slide. I dont know if
gripping the hardened tools has contributed to the jaw wear.

What's the best way to clean them up. The chuck jaws allow
external/outside edge clamping - can I wind the jaws out and fit a ring
and then run a boring bar across the inside clamping surfaces of the jaws
as someone here mentioned a week or so back?

Cheers.