Quote Originally Posted by mklotz View Post
I took a somewhat different approach. When the chuck is mounted I didn't want to have to use one tool to speed the jaw movement, then put it down and pick up the supplied chuck wrench to tighten the jaws.

I mounted a 1" diameter aluminum cylinder to one arm of the chuck wrench. It's held in place by a setscrew bearing on a flat filed on the wrench arm. The top of the cylinder has a hemisphere turned on it.
I have a similar key to yours with the exception that the upright is welded on not held with a screw. Your larger diameter, ball ended version would be more comfortable.