Steadicam Improvement (II)

This is the following of my previous design (www.thingiverse.com/thing:2843443).
It applies to a widespread steadicam sold under different brand names (Roxant, Viltrox, Easttowest, Afunta, Andoer . . . ). I found that the ball head was not so smooth, even oiled as adviced in many forums.So I decided to replace it by a combination cardan/ball bearing (see pictures).The cardan I use is a RC model found on Ebay (6mm int./11mm ext.)