If you are referring to the Dubro links that thread on and have a bolt going down through a ball socket into the control horn. Go right ahead. I am going to use them on my RCM Advanced Trainer that I am currently building. They are very strong and precise. If you mean a ball and socket type hook up I agree they are better off not being used. Sullivan's look ok but i still would not trust them. Good luck.

Mark Shuman

BTW go ahead and use the 4/40 stuff. It is a little heavyer yes. But much stiffer and all in all would make the plane more responsive.