1. Take a regular connector and cut it in half using two cuts right up against the center barbs. This leaves only the barbed ends, not the flat part in the middle. Sand the cut areas until smooth and level. The cut ends need to be able to rotate against each other without getting caught up on snags.

2. Take a brass bolt, just a little longer (1/4"?) than the two barbed connector pieces end-to-end, with the head just a little bigger than the hole in the connector, and the shaft just slightly smaller in diameter than the connector's center hole. You don't want wiggle room. Thread the bolt through one barbed connector part, then put a rounded black plastic hose/plumbing washer on the bolt shaft, then the second barbed connector part.

3. Take a dab of gorilla glue, put it on the threaded end of the bolt, and screw a cap onto the bolt that is the same size as the bolt head, being very careful not to glue the bolt to the connector itself (the bolt should hold the connector parts together very snugly, but also allow the connector parts to rotate independently of each other - this is how you get the "twist"). I tightened that as much as I could with pliers, so it would not come unscrewed while collapsing and unfolding the hoop. If it's loose or has any give, it will pinch you, and it also won't hold it's shape. That said, don't try to rotate it while the glue is drying, this will weaken the bond.

4. Let the glue dry overnight.

5. Assemble the hoop in the regular way, using the new rotating connector. I used 3/4" 160 psi tubing. This method didn't work so well with 1" tubing because its harder to coil, but it would probably work with lighter weight tubing--I haven't tried it. The smaller the hoop diameter is, the harder it will be to collapse--you'll probably want to use lighter tubing for small hoops.

6. I wrapped either side of the joint with gaffer tape, both to easily identify the twist point and to make gripping it while twisting easier.

7. To collapse it, hold the hoop upright, parallel to your body, with your hands on each side of the joint. Put your foot on the bottom of the hoop and hold it against the ground firmly for stability. Grasping the hoop tightly, rotate your grips in opposite directions, one toward your body and one away, while gently pushing down. The hoop should start to twist and fold. You may have to adjust your grip as it is collapsing. When it's in a flattened figure-8 shape but not completely flat, put one hand (or the foot that isn't stabilizing the bottom of the hoop) on the joint, pressing down gently to keep it folded, and grasp the outside of one of the outer round "wings." Then move the hand still near the joint to the outside of the other wing. Bring your hands together, as if you're closing a book. This should complete the collapse. I then hold mine closed with a velcro strap, otherwise it will pop open like a butterfly.

8. When unfolding, use the same technioque in reverse. It will take a little use or rotatin the joint in the opposite direction to fully return to a round shape.

9. Do not store folded. This will make it really hard to return to the hoop shape.