Soup Can Savonius

Step 3 Cutting some wood

There are a couple options here. (1) You can put a screw in the wood and make a string round a pencil the length of your radius and make your circle on your plywood that way. (2) I used a scrap piece of 1x2 and drilled a screw clearance hole about an inch in from the end. Then measured the radius and drilled a hole centered on the radius for a pencil to fit. Then I partially screwed through the clearance hole into the plywood and traced my circle. I found it to be nicer than the pencil and string for many reasons but mainly the pencil was kept at same angle since it was sized to the hole and not able to angle it like the string method. The other thing that I really liked was that it was easier to get a more precise diameter since I didnt have to worry about string stretch or tying a perfect knot etc. You will need 3 discs of wood.

Once you have your circles drawn, cut them out with a jig saw or scroll saw or band saw etc. Draw a nice straight line across them through that nice screw hole in the middle. Mark one of each; top, bottom and middle. The middle should have a line on each side, 90deg. from each other. Draw the one line on one side. Draw transfer lines on the side of the wood and draw same line on other side. Then use that to draw another perpendicular. Cross out the transfer lines so you dont get confused.