Helical wave spring

The wave spring has the same travel and force as a normal helical spring but only needs half the space(height). I thought I'd give it a go with SW, maybe not the most elegant modelling methodology but I think it turned out okay, there is some adjustment in the equations but it sometimes falls over maybe someone else could refine it further. Oh and thanks to http://grabcad.com/w.wolf for the right answer from Q & A :)