Yeah, so ahm doin a fixture that requires soft jaws on the back of the moveable jaw, so I said, Hmmm, what's this middle screw doin here? and took it out. Yeah, hilarious.
So I discovered that hemisphere ditty, which presumably is how Kurt generates that downward force.
So I blew everything out with air, put shit back together, and the Q is: How tight should that set screw be? Very tight, and the jaw is difficult to move. So how tight? "Smooth" action? "Firm"?
Odd design, that moveable jaw, imo. I would have expected that hemisphere ditty on the rear of the moveable jaw, as well, or some kind of incline on the back to force the back of the jaw down, as well.