First you must have full size cross sections (about 10, from root to tip) of your propeller. There are tools online for designing propellers, but you will need some CAD software to create the drawings and 2-D cross sections. I used CATIA, but any 3-D modeling software will do. (I also have a detailed instructions on design of propellers here (www.aerodyndesign.com) Of course you will have to print out the cross sections of the propeller on to paper, at full scale size. Because you will need to cut them out and glue them to thin peice of aluminum or tin.