Years ago, Graupner used to market a variable-pitch propeller. This unit used a separate servo and supposedly worked just like the real thing. Whatever happened to them? Were there any problems associated with them (shedding blades or runaway RPM etc.)?

Does anybody do something similar now? I have in mind to build a turbo-prop model and it doesn't seem right to use a fixed-pitch prop.

Any suggestions welcome - thanks.

Greg

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As a matter of fact, I was talking to a fella about this very topic yesterday. I don't see why an enterprising person could not take existing helicopter rotor head technology and use it to produce a controllable pitch prop.....and maybe with some electronics, a constant speed prop.

visit

http://www.rcuniverse.com/showthread...268&forumid=59

mecc

i've been trying to figure this out myself for an electric 60" corsair, needs a big prop. i'll let you know if i come up with anything, i'm going to scavenge through the helicopeter parts at the local this weekend.
dennis

I don't know in which year it was, but I believe to remember Hanno Prettner used such a system for a little while. I think the main problem was (it was before sophisticated computer radios) to pilot it, as you had to set throttle AND pitch. A constant speed kind of system is almost required to fly an RC variable pitch prop.

Look at MEC thread, what those guys are doing is just incredible !

Bernard

BerniG, I posted the same yesterday in the 4D Forum. I heard thou that the main problem was the servo in charge of managing the propeller angle or pitch, probably due to the torque needed.

As far as I remember, Hanno used this setup for just one championship. I don't remember the brand of the VPP, but it could be Graupner (Hanno used their radios those days), or MK.

Thanks

I know for a fact that these props were made by MK and the problem was that the blade was a plastic type over a metal insert .The reason they stopped producing them was constant mechanical failure which they suffered from.