I know someone has been over this before elsewhere, but slicing curved ribs from a template is much much much easier and more accurate than curving it by soaking/drying.mrsteven wrote:definitely use curved ribs, airfoils are extremely more efficent. if you soak the balsa in hot water for a few minutes than stroke the balsa across a light bulb (60 watt etc) until its at desired curve. Let it dry, I know that works but if you have the money and the time I'd order them from someone with a lazer cutter
Here's what you do. Get a sheet of metal that is thin enough to cut with scissors but still thick enough to retain strength. Home Depot and other hardware stores sell sheet metal like this for relatively little. Aluminum cans would work but they are usually not tall enough (perhaps one of those tall energy drinks or an arizona iced tea can would be fine). Cut a sheet of the metal out such that the one direction (probably your long one) is the same length as the longest rib you need to cut and the other is a couple inches long, just enough for you to be able to hold it down firmly on your board. Draw whatever shape rib you want along one side. Straight circular arcs are fine, but if you want to get fancy and have a taller leading edge on one side that's fine too, experiment, see what works best. Cut this shape out with scissors. You now have a template.
Cut a sheet of wood (probably 1/16", maybe 1/32") as long as your longest rib (the same size as your template). Make sure the grain is running the same direction as your ribs will be. Lay the template on top of the sheet and make a slice in the wood using the template as a guide with a sharp razor blade. Slide the template down 1/16" and repeat. You now have a curved rib. Repeat along the entire length of the sheet and you will get a number of ribs.
