Improving cheap drill chuck runout.

Another approach, if you are serious about improving this chuck (and really determined) - make a new arbor. This is not my idea, but pretty straight forward:
- starting with a suitable candidate piece of bar cut the J3 taper and rough in the MT2 taper (you'll likely use tailstock support so leave it plenty long). Install this on your candidate drill chuck.
- chuck up a little scrap of bar and skim it to make a driving pin (do not remove this from the chuck). For your 5/8" chuck, I'd go with at least a 3/8" pin (sort of mid range for the chuck - of course a larger drive pin would be better, but you want mid range for the chuck). Certainly if you have a dead nuts collet chuck then just grip a dowel and use that for the drive pin.
- go back to your developing arbor - trim off that tail stock support center (hacksaw and grind/file sort of square). Leave it long enough for the drive flats.
- grip the drive pin with the drill chuck - then carefully (sharp HSS tool, lots of back rake, light cuts, not too fast) square up that outer end and pop a new center hole.
- go ahead and finish the MT2 taper (up to you whether you add the drive flats, they are a good idea, especially on a 5/8 chuck, but not absolutely necessary - depends on what machine you will be using it on).
- final step, check yourself into the "nut house".
Congratulations, you now have a reasonably accurate cheapo drill chuck. The run out will be quite a bit better - it will still be a low quality drill chuck.

Avoid all the above - buy a good drill chuck and arbor. As DeadAim pointed out, it does not need to be USA built, just good quality.

Credit to others:
http://www.chaski.org/homemachinist/viewtopic.php?t=87063
 
To all of you who have responded. Thank you! All good info and advice. I will be investing in a better chuck soon but it might just be fun to improve this cheapie or wreck it trying. I never claimed to be that bright. The great response and free sharing of ideas on this site is truly mind blowing and I wish I could work with all of you and absorb just a fraction of your knowledge. For now I'm still smiling and looking where I have a few "chuck bucks" stashed away for the replacement.


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In the radio trade back in the day when we did component level one "style" was "troubleshoot via alignment".

When you had a unit that was "almost there" and a meter panel that just plugged in you did the alignment or tune up procedure and in doing so a bad stage simply would tune funny or if it was just out of tune then the process was easy fix.

How does this apply here?

You can tune your chuck...

Get it off the spindle and tear it down.

Inspect each part for fit and finish.

Ink everything with a felt pin and assemble it then adjust from zero to full then tear it apart and compare different marks and stone things for possible better fit.

Most likely jaws are too loose but maybe can be tuned up.

Maybe not but you learn how to service the chuck and that applies to almost all so better to experiment with the "no-count" one...

If you make any changes do only ONE thing to ONE item so changes for better or worse can be clearly identified.
 
John, when faced with a similar situation I bought a new Porta drill chuck, a heavy duty model AP13J6 and a new arbor for it.
http://portachucks.com/ENGLISH/product.asp?bheight=480&bwidth=1195.
It only cost $85 CAD for what I call the Ferrari of drill chucks (although it might actually be the Fiat of drill chucks :)

That way I could work on my light duty budget drill chuck for educational purposes and not worry about mucking it up. It turned out that the chuck just needed to be cleaned and deburred. Now it is back together and working smoothly. It was a satisfying project.
 
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