Two blade, prop pitch.

[Paul Allen]

Guy's
     What is the affect of having different pitch in both blades
eg 6" pitch in one and 5.5" inthe other.
Thanks

[peabody]

Noel "We have the Technology" Drindak wrote a SNews column a couple years ago about this....blamed it on Winfred, as I recall.

[Mark Scarborough]

I think I got this info from that article actually, but to paraphrase what I understood. The theory is that when you are in level flight only one blade is actually pulling, or to think another way, the blades are actually fighting each other, when you put a load on it, as in climbing, then both blades are pulling the plane putting in power. I understand it helps with controling speed.

[Alan Hahn]

The net effect is a pitch of 5 3/4.
Remember, on most props the pitch isn't helical anyway, so the pitch varies along the length. Of course it is better if the two blades are identical, but at our rpm (middling to low), it probably doesn't really matter in terms of uneven loads etc.

[Dennis Adamisin]

Guy's
     What is the affect of having different pitch in both blades
eg 6" pitch in one and 5.5" inthe other.
Thanks

My experience with unequal pitch is that it is a REALLY bad idea.  Props like that are good for stirring paint - not much else.

[Clancy Arnold]

I was told by an old time speed modeler Ned Morris that he intentionally had props with two pitches for 1/2 A speed flying. 

His explanation was that it took off and accelerated on the low pitch and then would "shift gears" and accelerate again on the high pitch prop to its top speed.

Ask Joey about it, he used to fly his speed models.

Clancy

[phil c]

No matter how you cut it, if the prop blades do not have the same shape and pitch distribution, parts of one or all blades will always be causing more drag than need be.  If one blade is 6 pitch and the other 5 pitch, when the plane is flying one blade will be partially stalled, and the other delivering only  partial lift.  If you change the load(maneuver) one or the other blade will start producing more lift, but the other will lose some, so you end up with more drag and less lift.

Best bet is to try for equally pitched blades.

[Alan Hahn]

When you are flying, the blades are pretty far away from being stalled, since the AOA isn't large. And as I pointed out, the pitch isn't really constant along the blade anyway (for most props out there).