Adjustable chuck jaw - video

[Jon]

Adjustable chuck jaw. By Maurizio Guidi. 19:41 video:

[tonyfoale]

Post content removed.

[Frank S]

Tony I think you misunderstood what he was trying to accomplish. His goal was not to create a method of centering a workpiece but to create an excentric offset cylinder to the centerline of the main cylinder. For this you would only want a single jaw to be out of time on the scroll to the other two. By adding the grub screws to a single jaw , he can micro adjust the amount of offset desired, instead of using shims

[tonyfoale]

Tony I think you misunderstood what he was trying to accomplish. His goal was not to create a method of centering a workpiece but to create an excentric offset cylinder to the centerline of the main cylinder. For this you would only want a single jaw to be out of time on the scroll to the other two. By adding the grub screws to a single jaw , he can micro adjust the amount of offset desired, instead of using shims

That explains a lot. The forum does not allow deletion of posts so I edited it to remove the irrelevant content. My comments about using soft jaws as the basis is still valid. Thanks for pointing out my misunderstanding.

[Frank S]

That explains a lot. The forum does not allow deletion of posts so I edited it to remove the irrelevant content. My comments about using soft jaws as the basis is still valid. Thanks for pointing out my misunderstanding.

Yes, soft jaws would have been easier for him to make the modifications to. I don't recall ever seeing any for chucks which do not have removable top jaws. Maybe there are jaws available that are only have the scroll teeth hardened.
This brings up another interesting point. After annealing a hardened jaw and machining for the grub screws what guarantee the proper hardness could be returned to scroll teeth