Feed Back on Drill Chucks

[Sandia]

I was wondering if you guys could give me some guidance on this issue. Please excuse the long post.

1. New Albrecht 1/2" chuck with integral jacob shank - .001 runout. No issues.
2. Older Albrecht 1/2" chuck bought off ebay, looks nice has 5/8" Rigid brand shank. Use on mill. Always has .009 runout.
3. New Jacobs Super Chuck 5/8". R8 shank. Use on mill. Has .007 runout.

Is the runout on the last two chucks excessive especially the new Jacobs. Also would it be advisable to rebuild the Albrecht or send it in for rebuild?

Thanks

 

[Ray C]

Where are you measuring the RO from, the chuck body or a precision rod mounted in the chuck? The only place it matters is how true the bit spins. I have probably 4-5 different chucks (all cheap to mid-level) and all of them are about +/- 0.0015 (total 3 thou runout).

BTW: If you measure with a rod, don't use a drill bit. Upon heavy use, they tend to get bends at the intersection of the heat-treated fluts and the soft end where the chuck jaws grab. Use something trustworthy. Finally, it's not uncommon at all for chuck bodies to wiggle all over the place while the bit is spinning dead on.

I was wondering if you guys could give me some guidance on this issue. Please excuse the long post.

1. New Albrecht 1/2" chuck with integral jacob shank - .001 runout. No issues.
2. Older Albrecht 1/2" chuck bought off ebay, looks nice has 5/8" Rigid brand shank. Use on mill. Always has .009 runout.
3. New Jacobs Super Chuck 5/8". R8 shank. Use on mill. Has .007 runout.

Is the runout on the last two chucks excessive especially the new Jacobs. Also would it be advisable to rebuild the Albrecht or send it in for rebuild?

Thanks

 

[Ray C]

A couple more things...

To really know the RO, check with known round shafts at the minimum, medium and maximum diameters for the chuck. It can vary. Also, a few thou total RO is acceptable for normal drilling. If you want dead on precision, use a dedicated endmill mounted in a dedicated endmill holder or suitable endmill chuck (ER-type etc). Avoid at all cost using drill chucks or collets for holding endmills as that's a recipe for ruining them. Also, the triangular shaft (Silver-Demming) type drill bits are notorius for putting a quick end to a drill chuck if they happen to catch on the workpiece and do a partial spin that wedges the jaws (ask me how I know). And finally, fully insert (as much as possible) the drill into the chuck close up to the flutes. If the bit is barely inserted, the jaws get uneven pressure on them when you tighten the chuck.

Ray

 

[mikey]

Might be the chuck, might be the arbor, might be the way the chuck is mounted on the arbor, and I agree with Ray on everything he said. Personally, I replace any arbor I find on a used chuck, especially a chuck from ebay.

I suggest you rebuild the Albrecht yourself if you determine that the chuck needs it. Albrecht can rebuild it but it is an expensive service. These chucks are simple to rebuild at home and instructions are easy to find on the net.

My Jacobs Super Chuck is a fine chuck but it is an older, USA-made one with minimal run out. I just learned in another thread here that the newer ones are made in China and all bets are off with those. Is it possible to return it and buy an older super chuck in nice condition off ebay?

 

[Ray C]

...And (another) final note -until the next one.... The spindle in your drill press is probably not ultra-precision. Most of them are very simple designs with a lot of clearance. If you really want to check the accuracy of the chuck, mount it in a precision mill with rock solid bearings.

And finally, don't get too hung-up on drill chuck accuracy for home-shop work. Yes, it good to know where your equipment stands but general-purpose drilling does not require precision much beyond a few thou (unless you're making clock screws of some ridiculously small diameter). Anything from #4 on up... life goes on if you're off a couple thou.

Ray

 

[Sandia]

A couple more things...

To really know the RO, check with known round shafts at the minimum, medium and maximum diameters for the chuck. It can vary. Also, a few thou total RO is acceptable for normal drilling. If you want dead on precision, use a dedicated endmill mounted in a dedicated endmill holder or suitable endmill chuck (ER-type etc). Avoid at all cost using drill chucks or collets for holding endmills as that's a recipe for ruining them. Also, the triangular shaft (Silver-Demming) type drill bits are notorius for putting a quick end to a drill chuck if they happen to catch on the workpiece and do a partial spin that wedges the jaws (ask me how I know). And finally, fully insert (as much as possible) the drill into the chuck close up to the flutes. If the bit is barely inserted, the jaws get uneven pressure on them when you tighten the chuck.

Ray

Thanks Ray, I checked the RO on my mill, which has no RO. I checked the chuck at the shank, no RO, on the chuck body, top and bottom, no RO. Checked RO with new Cleveland drill bits (not used) and thats where the RO shows up. Also checked it with new center drills, same thing ???

 

[Sandia]

Might be the chuck, might be the arbor, might be the way the chuck is mounted on the arbor, and I agree with Ray on everything he said. Personally, I replace any arbor I find on a used chuck, especially a chuck from ebay.

I suggest you rebuild the Albrecht yourself if you determine that the chuck needs it. Albrecht can rebuild it but it is an expensive service. These chucks are simple to rebuild at home and instructions are easy to find on the net.

My Jacobs Super Chuck is a fine chuck but it is an older, USA-made one with minimal run out. I just learned in another thread here that the newer ones are made in China and all bets are off with those. Is it possible to return it and buy an older super chuck in nice condition off ebay?

Yes, I found out after the fact, the new Jacobs are foreign made. Too late, I had used it several times. I am going to order the rebuild kit for the Albrecht and change the arbor to an R8, maybe that will help.

 

[Ray C]

Gotcha... Yeah, seems fishy. 2-3 thou I can live with. 7-9... Nope.

Thanks Ray, I checked the RO on my mill, which has no RO. I checked the chuck at the shank, no RO, on the chuck body, top and bottom, no RO. Checked RO with new Cleveland drill bits (not used) and thats where the RO shows up. Also checked it with new center drills, same thing ???

 

[mikey]

May I suggest tearing down the Albrecht first and check the condition of the jaws? There really isn't a whole lot that can go wrong with these chucks aside from worn jaws and oil in the spindle threads. I suppose the slots in the jaw guide can be worn but I haven't seen that in the seven chucks that I've rebuilt. If I had to guess, it would be the jaws or the arbor/taper having a burr or possibly a bent arbor. Albrecht jaws cost about $50.00 retail.

 

[Sandia]

May I suggest tearing down the Albrecht first and check the condition of the jaws? There really isn't a whole lot that can go wrong with these chucks aside from worn jaws and oil in the spindle threads. I suppose the slots in the jaw guide can be worn but I haven't seen that in the seven chucks that I've rebuilt. If I had to guess, it would be the jaws or the arbor/taper having a burr or possibly a bent arbor. Albrecht jaws cost about $50.00 retail.

Thanks Mikey, that is what I am going to do. Where can you order the jaws for the Albrecht chuck?