Fixing a casement window that won't crank smoothly?

This Truth Hardware stud bracket might be what you need.

It's specifically designed for use with Truth's Maxim Dyad and Encore Dyad casement window operators (the mechanism that opens and closes the window).

This is the LEFT-HAND version, so make sure you get the correct one for your window.

The bracket mounts to the window sash, and the operator's stud fits into it, providing a solid pivot point.
It's a common replacement part used by many window manufacturers.

The bracket itself is just the metal piece; you'll need to supply three #8 x 1-inch flat head sheet metal screws for installation (not included).

A pretty straightforward fix if your old bracket is bent or stripped.

Just match it up, drill pilot holes if needed, and screw it in.
Gets your window operating like new again.