Found this on Ebay Beech Roby prop

[cvavon]

http://www.ebay.com/itm/230916265325...=p5197.c0.m619

[RyanShort1]

Re: Found this on Ebay Beech Roby prop

Deleted.

Ryan

[TimHicks]

Re: Found this on Ebay Beech Roby prop

These props work with an A-65? How do they work? How do you get manifold pressure to the prop? They work with tapered shaft engines?

[Hank Jarrett]

Re: Found this on Ebay Beech Roby prop

1) Yes they work on a Continental 65 with a tapered shaft and I think they were certified up to about 90 hp on a Taylorcraft.
2) They are mechanical controlled pitch using a planetary gear system to change the pitch through a hand crank in the cockpit.
3) The manifold pressure is NOT to move the pitch, it is to see how much you are loading the engine.

No engine oil or electrical power is needed to change the pitch, you just turn the little window winder or knob on the panel. They actually work very well but are a little "fiddly". You also can't fly a plane with one with a Sport Pilot ticket.

Hank

[Hank Jarrett]

Re: Found this on Ebay Beech Roby prop

Here is a picture of a 45 Taylorcraft with a Beech Roby prop. They are especially nice for planes on floats since you can have a take off prop with a flat pitch for maximum efficiency and then go to a coarse pitch for cruise.
The flat pitch would be a joke for cruise and you couldn't get off the ground in cruise pitch. Controlling pitch is like significantly increasing your HP.
Hank

[Robert Lees]

Re: Found this on Ebay Beech Roby prop

An aircraft repair shop that I work at occasionally has several Grob 109 motorgliders that come in for annuals.

The mechanical prop pitch change mechanism is quite rudimentary (cables and rods) but it appears to work quite effectively (it is German, after all).