A friend requested fittings to make a pyramid topper for a pvc cube, so I made these. They are designed to work with my series of 1/2" PVC fittings. You can build a box with a pyramid top by using the 3-way elbow for the bottom joints (http://www.thingiverse.com/thing:533492) and these pyramid elbows and topper for the top joints.
The angle is 45 degrees, so it is scalable to any pvc length AS LONG AS YOUR HORIZONTAL AND DIAGONAL PIPES ARE OF EQUAL LENGTH.
I will continue to add new fittings to the series and share them as a derivative of my original 3-Way Elbow.
I am not currently able to respond to requests to make these in different angles, but you are welcome to make your own using the provided Sketchup files. Please tag your new creations with #HalfInchPVCFittings.