OK. Issue is on my end. I can only see one pic. See
I can't view your huge pics with my craptacularly slow middle of nowhere internet.
I finally saw them after a wait.
Your issue is the whole set up.
You have no leverage. That bar. Umm ain't gonna work. Your pulling close to the pivot, and the work is at the far end.
Is there any way to make the cable pull on the actual caliper lever?
The caliper also needs some more bracket to hold on to. As is, it looks like it will twist out of place.
Maybe these other guys can see something I don't but I don't see a way to make what you have work. I'd remake the bracket and cable setup.
Tighten the set screw like mentioned above and just see if that helps any.