Bending Aluminum Tube/Pipe

Sooo... I need to bend some aluminum tubing. It has relatively low structural requirements (I can explain that further later). We are working with 1.25" schedule 40 with 1.66" od, 6061-T6 (open to suggestions on preferable alloy, wall thickness etc). the final piece is akin to a right triangle where the hypotenuse has three radius bends that are tangent to each other toward the center with no straight between the bends, either end bent one direction and the center bent the opposite direction. For the prototype, we used two pieces of the tubing, three formed weld on elbows to make the right part of the triangle, bent cut and welded the three bends together to make the 'wavy' hypotenuse.

I want to make a die set that will bend this in one shot. One static and one hydraulically assisted. Here's where it gets fuzzy for me. How do I calculate the over bend so that I get as close as possible to exactly what I want when it springs back. Assuming some trial and error is inevitable.

Who knows, Happy Gilmore said it's just easier to put the ball in the hole in one shot!