The first circle CCRs were built by a fellow named Dennis Cherry (see first picture below). He made them from rectangular steel that was bent into circles. His circles were held in place using steel stakes, you can also use 1/2" or larger re-bar. He used 5 foot lengths, two per circle spaced 63" apart. To attach the circles to the stakes he used hose clamps (see second and third picture).

You can custom order hula hoops to whatever size you would like if you just google "custom hula hoop". This could be an easy option for many people instead of building your own.

I made the circles out of PVC pipe (see third, fourth, and fifth pictures). Below are instructions from Al Thompson describing how he made circles:

For each circle I used:

• 4 - 1/2" slip t's - Lowes $0.33 each #23873
• 1 - 1/2 slip cross - Lowes $1.32 #224087
• 1 - 10- 1/2" Schedule 40 PFC White Pipe $2.07 #23966
• 2 - 10' 1/2" Gray Conduit Schedule 40 $1.80 #72808

I cut the Gray Conduit into 4 pieces each 48" long.

I cut the White PVC into pieces 29 3/4" long.

I just pushed all the pieces together and it held.

I then added the Cosmic Color ribbon using 27 8" Releasable cable ties. I put the ties on every second break in the ribbon where there are no electronics. You can't pull them too tight or they will damage the ribbon. That's why I used the releasable type.

You can use two string lines to keep everything straight and level. One string line on the ground for the stakes placement in a line, the other string line is for the clamping height of the circles and goes between the first and last rebar stake.