An Introduction to the Parabolic Solar Cooker
The Paraboloid Shape
The paraboloid is an interesting shape with some amazing qualities. It has the power to concentrate light, electronic waves, sound, etc. to its focus at the center. To find the focal point of a paraboloid, one must use the formula, . To find y, measure the depth of the dish, and to find x, measure the length from the center to the outer brim. You have to pretend that there is an x,y axis going through the center of the dish. The two numbers represent a point on the paraboloid, and from that, you are able to determine where the focus is.
A Brief History
Parabolic cookers have been used for centuries now. The idea to concentrate light using curved mirrors was developed by the Greeks, Aztecs, Incas, Romans and Chinese. The Incas used bronze and gold for their mirrors and they built structures that were several stories high. This technology seems to have appeared around the same time for each of the civilizations. It is thought that {{WP p|Archimedes|Archimedes harnassed the technology]] to defend Syracuse from invading Roman fleets in 212 BC.
My Parabolic Solar Cooker
A Brief Description
At first, I was open to anything to construct the solar cooker. I was thinking about constructing my paraboloid out of cobb and then sticking small pieces of glass into it as I've seen others do. However, it takes a lot of time to collect the cobb materials and build a paraboloid out of it, let alone one whose focus was accurate. But while rummaging around Arcata Scrap and Salvage one day, I came across an old mesh satellite dish and I knew I had found my cooker. Bart and I hauled it to the Bike Library where my cooker began to take shape.
Location and Help
Most of the construction and testing took place at the Arcata Bike Library with the help of Bart Orlando. However, I did most of the cutting of the sheet metal at the HSU sculpture lab. We also used the tools there to construct the mount hot plate grill.
Materials Used
- Satellite dish (6 ft. in diameter)
- Sheet aluminum
- Conduit piping
- A bike rim
- Aluminum rivets and washers
- Nuts