Quote Originally Posted by Frank S View Post
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.