What I have now will do till I get more adventurous. Should be fine with the weight of carts I have. From that site, it seems the outer tube does screw onto the brass shaft. But the collar on the gimbal housing allows the brass to turn, so the outer tube won't screw out, or tighten down. There are 2 tiny set screws bellow the collar that must hold the collar in place, but I'm kinda worried I'd strip them out.