New to Forum 3 jaw chuck troubles

[gaston]

I cured a minor run out on a 3 jaw by moving all 3 jaws around the chuck by 1 position ( keep them in order #1,2,3 as they need to go on the scroll in order

[SteveM]

I cured a minor run out on a 3 jaw by moving all 3 jaws around the chuck by 1 position ( keep them in order #1,2,3 as they need to go on the scroll in order

Interesting. That would cause the jaws to engage a different part of the scroll at the often-used diameters where the wear would be the most.

Steve

[BadDog]

Actually, that wouldn't generally be the case. It would just be that the scroll would be clocked different. To get the same jaw offset the same difference from the axis, the scroll would necessarily be at the same point. However, if the scroll register (right term? race? bearing surface?) were a tiny bit off, you would see a difference.

[Harold_V]

Actually, that wouldn't generally be the case. It would just be that the scroll would be clocked different. To get the same jaw offset the same difference from the axis, the scroll would necessarily be at the same point. However, if the scroll register (right term? race? bearing surface?) were a tiny bit off, you would see a difference.

Give that man a cigar!

Harold

[juiceclone]

Two Cigars
I was getting a headache trying to come up with the variables in that.

[Harold_V]

Two Cigars
I was getting a headache trying to come up with the variables in that.

You see the same changes by simply using a different socket when tightening the chuck. The scroll shifts on its mounting point, so the more clearance it has, the greater can be the variations. That's but one of the reasons old chucks don't run well, although they often can be restored to virtual perfection simply by using soft jaws, which require that one use the same socket at all times, otherwise the jaws don't run true.

Harold