@Robert de Groot My mistake xD. I think it should be a centrifugal clutch. So that the yoyo comes back. I wanted it to have a freewheel, i.e. with ball bearings so that it can spin freely before you pull it back. However, since I only installed the ball bearings, nothing works, of course. I could remove them and insert another center piece so that it works like a really simple yoyo, but that wouldn't be my goal. Something like that in the Pic I would also need to use a longer screw because this one is much too short. However, since I haven't got the mechanism right yet, I haven't felt like cutting a screw to the right length. But that might actually solve the problem XD I would also have to grind the screw head to make it flatter or use one with a flat head instead.