# How To True A Drill Chuck On R8 Arbor?



## TORQUIN (Aug 9, 2016)

I have an Albrecht 1/2" chuck I bought without an arbor and installed it on a Shars R8 arbor for use in my Bridgeport. While it does what I need, I do notice that it has a bit more run out than I'd like. I mean, if I can see the run out, that's kind of much.
Is there anything I can do to get it closer, or zero?

Thanks,
Chris


----------



## Gerritt (Aug 9, 2016)

You would need to determine which of the parts has the runout. Use an indicator on the JT taper (without the chuck mounted). If that is out you know what to true up.


----------



## Bob Korves (Aug 9, 2016)

Buy an Albrecht arbor and install it properly.  But, really, what did the taper in the chuck look like before you installed the Shars arbor?  If an arbor had spun in there or if there was other damage, the only fix is by precision re-grinding the taper.  The new arbor may now be damaged as well if it was pressed into a damaged bore.  Albrecht arbors are the best, hardened, and the most accurate that I have found, but you will certainly get sticker shock when you see the pricing.  Jacobs arbors now come from China, the only thing the same as the old USA Jacobs arbors is the price...


----------



## mikey (Aug 9, 2016)

Chris, gerrity is right - you have to figure out where the runout is coming from. It can be a poorly made  or damaged arbor, a damaged spindle taper, a damaged chuck taper, or the chuck may just have been installed improperly on the Jacobs taper. You spindle may also have excessive runout all by itself.

Bottom line is that you have to sort out where the runout is coming from.

The first step is to get the chuck back off the arbor. They sell wedges that may help but Albrecht also sells a tool to do this specific job. If you prefer not to use a tool, you can always disassemble the chuck and press the arbor out from inside the body of the chuck but that going a bit far.


----------



## Tony Wells (Aug 9, 2016)

Mark your high spot and change to a different radial location in the spindle and see if the high spot moves. If so, it's not a bad spindle. If is stays the same, look at the spindle/bore. Take a collet and pin (or 2 or 3) and check their runout. If they are good, the machine itself is fine. Then proceed on to the arbor and chuck. Check different sizes pin in the chuck, from small to large, marking the high spot on the hood. This will tell you something about the jaws and scroll. Do all of this before you dismount the chuck. That should be last. These steps will help you know what to look for.

Offhand, I'd suspect the arbor, almost with certainty if this was a new chuck.


----------



## Sandia (Aug 9, 2016)

Had the very same thing happen to me. Bought a new Albrecht and cheaped out on the arbor. Broke down and bought  an Albrecht arbor and problem solved.


----------



## TORQUIN (Aug 24, 2016)

Thanks for the advice. I will check everything to determine the problem.

Chris


----------



## chips&more (Aug 24, 2016)

Get an Albrecht drill chuck with an integral shank.


----------



## Sandia (Aug 24, 2016)

Chris, another thought, if you change shanks get a 5/8" staight shank instead of an R8, even on a Bridgeport style knee mill, you run out of room often.
Just a suggestion.


----------



## TORQUIN (Sep 27, 2016)

I put an indicator on the arbor in the spindle, in two places. TIR .0005". Put a drill in the chuck and indicator on the drill shank just below the chuck jaws, TIR 0ver .015" (full travel of indicator). I would not expect this from an albrecht chuck. Next I'm gonna take the chuck apart to see if I can identify and smooth out any burrs inside it.

Chris


----------



## DoogieB (Sep 27, 2016)

Sounds like it's had a rough life but luckily Albrecht does sell parts.  This might help:


----------



## Surprman (Sep 27, 2016)

I bought and refurbished an Albrecht chuck.  When I was done it still has some run-out it thought was too much (around 0.004")  A couple (real) machinist friends said you simply indicate it and then give it a slight rap or two with a rubber dead-blow mallet.  I didn't believe it was kosher, but it brought it within 0.001".


----------

