So, me and my Senior Design professor were talking about coming up with ways to use some sort of parabolic mirror to focus solar energy for various energy savings applications. One of the things he brought up was something about being about to take a flat, circular piece of sheet metal and cut a spiral into it and then bending/stretching it into a bowl shape so that the surface of the spirals focuses the light into the same spot.

Anyone familiar with doing/figuring out how to do stuff like this? assuming it's even possible.

Does this kind of problem even fall under Topology.
Some recommended key search terms or just a basic explanation too get me started would be much appreciated.

Thanks in advance!


This is the basic gist of what I'm going after: "For camping trips and other activities it is useful to have a solar reflector for cooking or electricity generation. It can be made form a flat piece of material and folded into a three dimensional parabolic dish for concentrating solar radiation. The flat disk has a plurality of spirally cut segments, which can overlap when the segments are made to stand extending in a parabolic shape from their central circular base. The segments will overlap on their edges and can be fastened together near the circumference to form a parabolic dish for reflecting solar rays toward a central area used for cooking. The parabolic reflective dish can be disassembled and stored flat by removing the fasteners and urging the spiral side segments to lie flat. The number of spiral side segments and their size may vary. The parabolic reflector is easy to assemble and disassemble and easy to carry."

Here's a guy that did it but he just tinkered around with it til he got it right, I want to know the exact way to calculate it. http://www.ae-zone.org/Designs/altNRG/Parab_reflect.html

Double thread...

Double thread...This is the right thread. Idk how I ended up double posting, I must have hit enter or something when I went back and changed the title.

It's not economical/practical to use a piece of metal cut into a spiral to make a parabolic dish....The idea i suggested is 10x easier, probably the same cost, and can be focused/re focused with ease. The metal would probably rust, or it will oxidize reducing it's reflectiveness. A mirror moulded into that shape would be better, but it would have to be perfect or it's a waste of glass, stuff on the back on the mirror(aluminium? mercury? silver?), etc.

It's not economical/practical to use a piece of metal cut into a spiral to make a parabolic dish....The idea i suggested is 10x easier, probably the same cost, and can be focused/re focused with ease. The metal would probably rust, or it will oxidize reducing it's reflectiveness. A mirror moulded into that shape would be better, but it would have to be perfect or it's a waste of glass, stuff on the back on the mirror(aluminium? mercury? silver?), etc.I really appreciate your help, but apparently you seem to think we're in DIY; this is Mad Scientists, and the point of this thread is to learn the science behind this. I'm not actually trying to make one, I already have a big Fresnel lens for solar heating projects ;)

Go back and read the very last part of my OP and check out the link (http://www.ae-zone.org/Designs/altNRG/Parab_reflect.html).
On that site, the guy says: Figuring precisely how much to distort each strip took some hairy trigonometric calculations, accurate to six figures, which I undermined by hand-measuring and hand-drilling the mounting holes. I want to know what those calculations are.


It's not economical/practical to use a piece of metal cut into a spiral to make a parabolic dish....Actually, it can be both practical and economical in certain situations. Go back and read the second-to-last part of my OP. It could be practical in the sense that you can have a compact & collapsible dish, and economical in that it's cheaper to ship a flat sheet than a big bowl.