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Building a parabolic with mirrors.


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I can finally upload a picture of the solar death ray I made with a friend in summer '05 (see attached file). As I said, there are about 500 3"x3" mirrors on a 6'x6' wooden plate and the focal length was about 5'.

 

Yes, this is shameless bragging. ;)

"Shameless bragging" is an oxymoron.:hihi: Nonetheless, you built a nice looking setup. :) Did you use it for anything productive? Is it weatherproof? Do you still have it? :sun: :shrug: :cup:

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Did you use it for anything productive? Is it weatherproof? Do you still have it? :hihi: :shrug: :sun:

 

We didn't try to make anything productive with it since it would have required some kind of device to track the sun (the whole solar death ray weights more than 200 lbs, so moving it is not an easy task). We sheltered it under a plastic sheet and it spent the winter in a warehouse. We still have it but I haven't tested it much this summer (not at all in fact) because I was out of town. Some of the mirrors are now misaligned and I don't know what we are going to do with it for the coming winter.

 

I attached some pics of a burning cellphone.

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What kind of temperatures could to achieve with 500 3" x 3" mirrors?

 

 

It looks like you mounted the mirrors on woodblocks cut at the tangent angle of the parabolic.

 

are the mirrors adjustable?

 

Based on the diameter of our focal point (about 6"), the diameter of the parabolae (6') and the sun power (1000W/m^2), we calculated that a blackbody should have reach 1400C at the focal point. Yet we don't know if we ever reached that, since the temperature reached by an object depends strongly on its emissivity (I attached the pic of a burned beer can, it didn't melt much since it is quite reflective).

 

Indeed, we fixed the mirrors with cement glue on woodblocks cut at the tangent angle of the parabolic. Then we screwed them directly on the wooden plate, so they are not adjustable. We thought that building an adjustable parabolic mirror would take way too much time, so we didn't do it.

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  • 2 years later...

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