Perfecting the $5 Parabola (Part 2 of 2)

by Brad
(Las Vegas)

Now we're at the point where I tested the focal point, in the dark, with the Sun being simulated by a high powered flashlight.

The first picture shows where I was directly in front of the parabola. The next two were taken where the flashlight was at 60 degree angles to either side. The concentration point is right where I want it to be now.

Simple conclusion. Tension your parabola using the bow until the depth of the bow is just slightly less than half the length. Easy ball park numbers.

Place the parabola on a reflective bottom, like the CooKit

http://solarcooking.org/plans/cookit.htm

or make a duplicate solar bow, and form another, tighter solar cave, with that same reflective bottom.

I believe that a second, higher and angled-tier, will take this design to where I want its performance to be. As simple as the AIT Educooker

http://solarcooking.wikia.com/wiki/AIT_Educooker

but more efficient (although not foldable).



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Great Work Brad,
This is the kind of information that many of our visitors are seeking after, something that can help them achieve solar cooking results with a minimal monetary investment.
I, for one, am following the development of this cooker with great interest.

Nathan
Admin.