Very good indeed.
I am also in the brink of constructing one myself.
1) Did you use R2 and R3 or R1 and R2 radius ?
2) Seems like you have reached the top exit with 3 loops (assuming you are gong to stop there). What is the total height from ground zero to top exit ?
3)The thickness of the plywood you used?
4) and how on earth did you have it cut so smoothly? I can hardly see any joints where two parts meet.
5) finally the slope angle. Did you calculated it or was it a trial and error case?