spaco wrote:
> 20 thou is a lot.   I'd seriously consider getting a new one.   For
> years I fought a 6" 3 jaw chuck that was about 6 thou out.  I tried a
> couple of the solutions that you no doubt will get from this post, but
> they didn't work for me.
>   Finally, about 6 or 7 years ago I bought a brand new set-true chuck.
> Even though it cost me $350 (3 times what I paid for the whole
> (used)lathe 30 years ago,  it was and is still worth it.
>    It has 0.0004" run out.  I can simply throw stuff in there and cut
> metal.
>    You may not need a 7 or 8 inch chuck.  consider a 6" to hold the cost
> down.

>   You may be right about hurting the jaws with a drill or end mill. I'd
> also suggest getting a collet or two for holding them.  End mills in
> particular seem to pull out of the 3 jaw chuck.

> Pete Stanaitis

> ------------------------------------
> Den wrote:
>> 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.