I know this has been discussed, but I thought I remember seeing a diagram of what the trailing edge should look like to eliminate hum. Anyone have a quick reference to it?
thanks
pp

I don't know about a discussion thread but essentially all you do is bevel the inside trailing edge of each blade at 45 degrees...

I believe the current thought is to make the trailing edge asymmetric to reduce the hum. So angle one side of the trailing edge at a slightly different angle than the other and you should be okay...

I find my random sawtooth pattern on the back of all my boards eliminates all humming very effectively.

AHPC has the diagram you're looking for in the Viper tuning guide. The point behind the procedure is to make your rudders very slightly asymmetric.