DIY LED reflector, how to design one?

[djozz]

Perhaps Buckets go at it three years ago is a good read?

DIY Reflector

I've had this idea for a while now and finally dug in and got it done. I have the desire to make multi-LED flashlights, but really don't like the whole process of mounting individual reflectors so I figured why not try to make a bit that will cut my own. I've seen a couple of threads in here about guys making their own reflectors, but they were not parabolic. So I did the math using y = .875x^2 as my formula. I put it into a spread sheet so I could just move the wheels a set amount at a t…