Propeller pitch

[kmpillai]

Hi Friends,
In the propeller specification the diameter and pitch is given. What is the pitch of a propeller? and how it can be measured?

KMP

 

[rcass]

kmpillai,

The "design" pitch is based on the angle-of-attack of the airfoil section at a given station from the propeller rotational axis (centerline of propeller hub). Having worked for a propeller manufacturer once-upon-a-time I think ours, if I remember correctly, were measured from the blade face (opposite the camber side) to a plane parallel to the prop mounting flange at the 30" station. We made mostly variable pitch & constant speed propellers. There were variations (sometimes 10-20) on a given blade design that might have a slightly different twist resulting in a slightly different pitch. The pitch could also vary according to the blade's required position in the hub and the settings for a given application. It could be different for other manufacturers. So Check with the manufacturer to determine the actual location for the spec given.

 

[reidh]

kmpillai,

What rcass said is correct, but in simpler terms it is the distance that a propeller would travel if turned one full rotation assuming no losses or slippage.

Being an automotive guy, it was explained to me that increasing your pitch is like a higher gear. A low pitch prop will give you better acceleration but a lower top speed on a given engine.

There are alot of pitch gauges out there, below is a link to a picture of a hobby type gauge.

http://www.darrolcady.com/Propellers/propellers.htm