The top bars are 24″ long and all of the supports and legs are 6″ long. There is a very tight fit so I did not use PVC cement, instead I put a small mark on the top bars at the elbows so I can see if they begin to back out.
I used 1 1/4″ schedule 40 PVC and they are very strong (a little less flex than I wanted). If you weigh much more than me (I am about 165 lbs) or want much longer top bars then you will want schedule 80 PVC.
These are a bit thicker than I would want so I may buy 1″ PVC pipe and 1 1/4″ to 1″ elbows so that I can put them on top of the same base. This will give extra flex while still being strong enough.