Best way to fit a drill chuck arbor?

[Mr Ron]

What if any effect has the small amount of air trapped inside the taper bore?

[BadDog]

None that I've noticed.

Side note on using keyless to drive hole saws and the like. I generally avoid driving anything that is going to either hammer (interrupted) or require substantial torque using a keyless chuck. That "self tightening" feature can be a real problem, and I've read of folks having to use a pipe wrench to loosen afterward. That and driving taps is where the ball bearing chucks really shine.

[liveaboard]

I once saw mt2 + 3 holesaw arbors in a shop; wanted one but the price was beyond my idea of reasonable.

So my holesaw goes into the keyless chuck, and yes, I have a pipewrench handy if required.

[whateg0]

I am going to have to work at it too get it loosened up, for sure. It would be great to have an r8 shank on a hole saw and use the holes in the top to drive it like the one arbor I have does. This particular hole saw has an integral shank so I can only use it in a drill chuck.

[pete]

I've never had an issue with compressing the small amount of air between the two tapers. Morse and Jacob tapers are classed as self holding tapers. They hold by mechanical friction and a slight wedging action. From slightly loose to fully tight and how little distance that requires might be why there isn't much or any air compression problem.

Just like Badog has said, if a pipe wrench is ever needed to tighten or loosen a decent well engineered key less it means you already have or are distorting the chucks internals due to it's built in self tightening design. There was an older thread over on PM some years ago where some mentioned they had permanently locked up there key less by mistakenly using over sized S & D reduced shank drills in them. Nothing they tried would get them apart and the chucks were scrap. I've never once needed to use a strap or pipe wrench on any of mine. If the cutting tool diameter is larger than tool shank I use a collet instead. With the key type chucks and since there not designed to self tighten, then over sized drills, hole saws etc can be used. That doesn't mean you might not see tool shanks spinning in the jaws, but you won't ruin the chuck right away.

[liveaboard]

I put the new cheapo (presumably) Chinese arbor in a holder in the mill, and I could not measure any runout.
A center drill in the chuck, stuck lightly onto the arbor, showed 0.2mm runout, that I got down to 0.08mm. It's hard to tell if there was a sweet spot, or it just wasn't fully seated the first time.

[John Evans]

At least one chuck maker furnishes their chuck with a pin spanner wrench ,I think it was Rohm ? I had a correct size pin spanner laying around and made a small recess in the chuck body to suit, worked a treat ! My grip ain't what it used to be anymore !!

[Harold_V]

So my holesaw goes into the keyless chuck, and yes, I have a pipewrench handy if required.

I was gifted a 1/8"-5/8" Albrecht chuck, in new condition. It had been used to drive an overload, resulting in the cracking of the hood. A replacement was reasonably priced, so I now have a very expensive chuck that cost but a small fraction of a new one.

I make mention because over tightening offers the risk of cracking self tightening chucks. Just sayin'

H

[Steggy]

I generally avoid driving anything that is going to either hammer (interrupted) or require substantial torque using a keyless chuck. That "self tightening" feature can be a real problem, and I've read of folks having to use a pipe wrench to loosen afterward.

There should be a law against keyless chucks.

[liveaboard]

Or you can just have a pipe wrench named "Key".

[whateg0]

I'm going to have to make a spammer to get this one opened. I wasn't aware of the self tightening until it was too late. Then I decided that it was stuck so I was finishing the job. It'll either open up or it will be my r8 2" hole saw

[Bob D.]

The important point on keyless chucks is not to use drills beyond their rated range. Using a 1” Deming drill with a 1/2” shank is a no no in a 1/2” keyless chuck. Same for hole saws. Larger then specified diameters really up the torque applied to the self tightening feature.