If you measure center of GoPro lens from the base of the tripod mount it is ~2.5 inches x 2 gives 5 inches for height that centers the lens equidistance top to bottom. Then 1.7777 x 5 inches = ~8.8 inches for the width. Handles are 4 PVC SCH40 1/2", 4 flat top PVC 1/2" plugs and a little 1/2" PVC pipe to make the 8.8 inch height. Use a #8 or #10 screw in the center drilled plug so you can get a socket and lock washer and lock nut inside with the aluminium strip on top with a drilled (use the drilled plug to get exact center on strip) appropriate hole size. Used bike handlebar grip and cut to fit length of 1/2" pipe. The balls are standard but used a #10 screw so could tighten with socket inside plug. Glued everything but top strip and lubed the plugs a little and hammered home and sunk in a small screw to hold in place in case wanted to open it up later.
Also can get my JVC Picsio + Ikelite case with adapter mounted on this tray and put the GoPro on top if I wanted.
You probably will have $20 to $25 in parts without the balls unless you have a lot of PVC, aluminum, and stainless screws around, but you will have some left over PVC and aluminium. The balls are probably around $35 for two.
Ah, but the PVC Rig took some nice video so don't dis the ghetto gear
