Introduction: Solar Design T-square for Designing Solar Cooker Reflectors
I tried this on a small scale model and then scaled up.
It can better be used on a larger scale. You could also design flat parabolic "plates" with mirrors on a sheet of plywood to make powerful mock parabolic dishes. (In that case only one laser shining straight down is needed)
This shows how I used it to design the shapes of reflectors for unattended solar cooking.
(I did not know what the shape would be before I began.)
The design process is done by "Claymation". Little adjustments of one area at a time until the design is complete.
The clam shape has never been repeated even though it has great potential to help people in Dafur or Haiti.
The license is attribution sharealike so you can produce commercial versions too.