The project began in the summer of 2008 when Chris began experimenting with a large fresnel lens he purchased on Edmunds Scientific. Of course the most fun thing to do with large lenses is to go outside, face it to the sun and burn things with it. The lens was able to focus to about a 1/2" spot, which would get hot enough to melt a penny. (approximately 700 degrees farenheit.) Visit the development blog
Time to get ready for spring
Winter isn't eager to leave Tahoe. We got blanketed with 6-8" of fresh snow last night. Fortunately our materials were already safe and dry in my car.
I am getting tired of looking for buried projects in the yard.
We finished up cutting the openings in the inner box today. We started out with the oxy-acetlyne torch, attempting to "cut" holes in the stovepipe. It was fun, heating the metal into a molten pool and blasting through it with a blast of oxygen. We intended to clean up the holes with a metal file or mini-hacksaw however that was painstakingly slow. Instead we chose to use the angle-grinder. It made short work of the thin sheet metal, making 48 plunge-cut slots about 1/4" wide and 3" long, resulting in 12-3" squares.