Solar reflector mounted on part of an office chair, might give people some ideas.

http://www.youtube.com/watch?v=VhpwOD2gZLA is a video that shows a solar reflector that I made from mylar and an 8 by 4 sheet of corrugated plastic. I approximated a parabolic dish by cutting it to  make cones.
I used bamboo to make it more sturdy. (Still needs more bamboo).
It is on a stand made from an old office chair.  I intend to line up the mount properly and put it on equatorial mount but that will take a while.
It might be weeks before I have time to test the thing so here it is for now.   I am slow at the experiment stuff. The dish started last september! And it took me that long to figure out how to keep the shape resonably tight.
So here it is at this moment. It will change a lot before it is finished but no reason not to show the current state of the project.
Brian

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gaiatechnician (author) 6 years ago
The next stage of the experiment is putting the dish on "equatorial axis" .Equatorial axis is just an axis that is parallel to the axis of the earth. (it is easy, your latitude pointing at the north star (in the northern hemisphere) I did it a few years ago and there is a problem. You can never be sure if it is a bit off and if it is, you can go to correct it but you cannot be sure you are anyway right! So I did something different. I put in something flat for the axes to sit on. And in this case, you can check if something is a bit off kilter and you can adjust and improve this! So here is the  video explanation of what I did.  I have to state that I wiggled and leaned the pallet to get the bulseye level at the same time as the spoke made the tiny shadow on the piece of paper.
gaiatechnician (author) 6 years ago
I am going to try to embed the latest video.  It is
rimar20006 years ago
Gaiatechnician, I told you the mylar, acetate and other thin films, if aren't well stick on a firm surface, make innumerable wrinkles that dramatically reduce efficiency.

In the video that is seen clearly.
gaiatechnician (author)  rimar20006 years ago
Thanks Rimar. I goofed with the wheat paste. I put it on slightly askew and then had to twist the entire sheet of half stuck mylar on the 8 by 4 sheet of corrugated plastic. but the "cone solar" should generally work to have fewer wrinkles. (Because each cone is curved in just one direction). So the lesson is, use a different glue on plastic. (wheat paste cannot dry as a layer between mylar and plastic) It was definitely easier to do than the last dish that I did. I had to do many tiny cuts on that one because it curved in all planes. The "cone method" for makeing a dish is hardly ever used but it means a lot less cutting than the petal method.
I think the bamboo (or light plastic tubing) might be an option for holding backpack solar cookers together. I hope to change this setup to equatorial mount, which means a 7 pound (3kg) counterweight going on somewhere.
It is a work in progress. People can also subtitute square mirrors on a sheet of plywood for the dish. Don't get hung up on any part of the thing. Use the parts that you like in your design. Thanks, Brian
Kiteman6 years ago

Better to embed the video here:


gaiatechnician (author)  Kiteman6 years ago
Thanks. I just put this video up to show people some of the experimental options. I have not cooked or concentrated heat with it because this is not a finished product and I am extremely busy on sunny days.
However maybe it will spark people to try different things.