How to Make PVC Pipe Windmill Blades

Match the size of pipe you use to the scale of the project you are working on. As a rule of thumb, a pipe with a 4-inch diameter is suitable for a windmill that will stand 1 yard high while 1 foot tall windmill needs pipe around 1 inch in diameter. Use a length of pipe equal to one-quarter of the windmill's height.

Cut the pipe into four equal sections. To ensure the cuts are even, calculate one quarter of the pipes diameter. Using this figure, mark four equidistantly-spaced points around the mouth of pipe. Line up the handle of the set square with the rim of the pipe and place the metal section along the pipe's length.

Mark along the metal edge of the set square. .Continue these lines for the length of pipe. Use a ruler lined up with the marks to ensure straightness.Use a jigsaw to cut down the the length of these lines.

Take one of these quarter pieces and lay it down on its concave face with the long sides horizontal. Use the ruler to measure the short edges. Mark on the left edge, one-quarter of the way up from the bottom and on the right side one-quarter of the way down from the top. Draw a diagonal line joining the two marks.

Use the jigsaw to cut along this diagonal to produce a fin with a right-angle triangle.The hypotenuse of the triangle is the leading edge. Use sandpaper to shape this edge into a rounded curve and shape the other edge into a tapering point.