The Wood 103 | Otherpower This page is all about a rather silly, quick project where in about 1 day I built a small wind generator using the following items, and nothing else.... (1) Wood (2) Copper wire (3) Surplus Neodymium magnets (4) Dirt (5) 10" piece of 3/8" steel shaft (6) Two bolts, but these are optional. ...and that's all, unless we count glue, and linseed oil which I used for finishing. Pictured above is one of the magnets I used. Above you can see the armature for the alternator. Pictured above you see the wooden pillow block bearings. The stator, on which the coils are wound was cut from two pieces of 2" X 4" lumber. I dragged a magnet around in the dirt of my driveway, so that it would attract the magnetite sand. The dirt was mixed with epoxy, so that I had a thick paste. The completed alternator! To stay with the "style" of the project I decided to build the whole windmill out of wood, it's a fairly simple design and should be self explanatory. The prop is wooden, made from 1" X 4" lumber.
Parabolic solar oven The idea is that if the parabola is cut symmetrically along 8 radial directions and flattened out, then it would appear like an 16-petalled flower. So once you have the petals made of any flexible material you can bend them in the shape of a parabola. I used 5 mm thick plywood. I think you can use a thinner plywood, but then you'll need to add a stronger structure to stiffen the parabola. I used this publication to calculate the dimensions of the petals. Here is a google spreadsheet with everything you need (you can download it to modify it). modify the focal length of the parabola modify the number of petals choose the length of the petals I've also included a petal in svg that I created using Inkscape. Once you've cut the petals, drill holes every 20 cm along the sides of the petals so that you attach them together with the plastic cable ties.