Learned something new about drill chucks today

[savarin]

I needed to transfer some holes in two pieces of stainless sheet so I placed the two disks together then to align the holes I used a length of 8mm stainless rod held in the drill chuck and set it in the top hole then clamped it all to the drill press table.
Upon rotating the drill the rod prescribed a circle, I thought there must be bend in the rod so I quickly cut another, same problem.
Argh, my reasonable new drill press is wearing already???. Possible 0.5mm out
Nope!
I tightened the chuck with the key in one hole only as I always do then for some reason I tried using all three holes and gradually tightened the chuck.
Bingo, the rod is now perfectly centred.
I guess this is how I will tighten drills in the chuck from now on.

 

[Bob Korves]

I needed to transfer some holes in two pieces of stainless sheet so I placed the two disks together then to align the holes I used a length of 8mm stainless rod held in the drill chuck and set it in the top hole then clamped it all to the drill press table.
Upon rotating the drill the rod prescribed a circle, I thought there must be bend in the rod so I quickly cut another, same problem.
Argh, my reasonable new drill press is wearing already???. Possible 0.5mm out
Nope!
I tightened the chuck with the key in one hole only as I always do then for some reason I tried using all three holes and gradually tightened the chuck.
Bingo, the rod is now perfectly centred.
I guess this is how I will tighten drills in the chuck from now on.

Al least for the holes you really care about...

 

[pacifica]

I needed to transfer some holes in two pieces of stainless sheet so I placed the two disks together then to align the holes I used a length of 8mm stainless rod held in the drill chuck and set it in the top hole then clamped it all to the drill press table.
Upon rotating the drill the rod prescribed a circle, I thought there must be bend in the rod so I quickly cut another, same problem.
Argh, my reasonable new drill press is wearing already???. Possible 0.5mm out
Nope!
I tightened the chuck with the key in one hole only as I always do then for some reason I tried using all three holes and gradually tightened the chuck.
Bingo, the rod is now perfectly centred.
I guess this is how I will tighten drills in the chuck from now on.

Also works on 3 jaw lathe chucks.

 

[dulltool17]

Yes- the use of all three does improve run-out, as well as grip on the work the tool, for about any 3-jaw chuck of any sort.

 

[chips&more]

Not so fast. The author could have a bad drill chuck? But the other comments? A good 3 jaw chuck will have an arrow or mark indicating the best chuck key hole to use, not all of the chuck key holes. And sorry, but my good drill chucks don’t need any special tightening, one hole is enough…Dave