The Correct Wood Propeller

pkrankow wrote:In inch measure 5x3, 5x4, 6x3, 6x4 are acceptable propellers for general use.  These engines will turn up to an 8 inch diameter, 4 pitch prop, but your shouldn't go below a 5 inch diameter.  People have run 2 inch pitch, and greater than 4 inch pitch across these diameters successfully.

so that is , in metric...

127x76 = 5x3
127x101 = 5x4

152x76 = 6x3
152x101 = 6x4

203x76 = 8x3
202x101 = 8x4


The first number is diameter, the second is pitch.  Pitch is the theoretical travel distance of the prop in 1 revolution.

Now...wood is a difficult thing.  These motors turn such high RPM that finding a wood prop is going to be difficult.  If nylon is OK coxengines.ca and exmodelengines.com have props (and parts) for these engines.  There are other retailers who will carry props in this size range too.

Please don't be tempted to put an electric motor prop on, the plastic is too thin and the prop will break very quickly throwing bits of plastic and allowing the engine to over-rev.  

Phil