Upload & Sell: Off
I use a bunch of superclamps, electrical conduit, and a couple of autopoles for mine. Here's an image in a couple of different configurations (don't have one with a sweep on it handy, but you get the idea):
At the time it was cheap (I put it together during the financial crisis when you could buy used superclamps all day for $5 each and autopoles for not a whole lot more) - those days seem to be gone but you can do something similar with structural tube connectors (look at tek supply) fairly cheaply. for larger shooting structures I actually prefer the electrical conduit to a pvc solution - the larger diameters are really stiff, surprisingly light, easy to cut, and pretty cheep, but that's just me...