prop pitch?

[omega blood]

1st question: How is propeler pitch measured, degrees or inches?
The second # on a prop is pitch, is that # degrees or inches. If it is inches, why? Last is there a simple device that I can build or method that I can use to measure prop pitch?

[steve lewin]

Prop pitch is specified in units of length i.e. inches or mm. E.g. 8 x 6 is 8 inch diameter (or length) and 6 inch pitch. It is the distance the propeller would theoretically screw itself forward in one revolution if there were no losses.

Pitch is measured by measuring the blade angle at various points along the blade and then coverting for the diameter. It is possible to build or buy a pitch gauge, the Control Line guys and serious pylon racers use them a lot, but I haven't seen one for ages.

Steve

[omega blood]

Thanks Steve.