I have an aircraft that I support that needs a lot of propellers. The aircraft is called a Pixy Drone, an RC parasail(foil) controlled unit powered by a 23cc (1.4cu In) Bergonzini Boss Tech engine. It is made by ABS Aerolight. The unit is used in a rough environment, and anything that hits the prop (grass, corn cobs, small stuff, almost exclusivly on take off) nicks or breaks the prop, leaving them a problem to use. So far, we replace, but this is really starting to hurt cash wise. The engine can spin up to 17000 RPM, but with this style prop, its known to spin between 7600 - 8200 RPM.

The props are listed as 17X4, and have a 3/4" bore for the drive shaft. The actual prop length is 16 and 5/8 inches, with squared off tips. Its a wood laminate (5 ply) and looks to be Maple and Black Walnut. The maker tells me its made on a computer driven lathe from CAD CAM drawings and design of his own.

The props are a huge expense, even more now that the company that makes it is European, and the rate is today 1.17 USD for each Euro. I see several makers of props, glass and carbon fiber, and attactive prices, but non with the same pitch. Also, nobody seems to list the bore either, and I'm thinking of a drill press to adjust. I am aware of changing the size and pitch tradeoffs, and am thinking its worth the try to go with a smaller diameter prop (better ground clearance) and a greater pitch (only 6 and 8's are in the US market that I can see) and still get comparable RPM's and perhaps the thrust needed to basically work this thing. Does anyone have any pointers for making this change? Any suggestions for good props in US for better prices than $141.00 USD?