I have not used ball links to date on my pushrod controls but plan to use them on my future builds or model repairs.
I recently purchased a few NIP 2-56/4-40 Dubro swivel ball links. On the first ball link package I opened, I noticed that the ball did not rotate smoothly within the link. On the second one I opened the ball did rotate freely. I guess my question is if this is a one-off poor-quality link? Have others experienced the same issues with these Dubro links? Obviously, a stiff ball link should not be used.