Has any one made a motor that will turn a ductaed fan and a prop.

[canadian_bacon]

I would like to try make an v-22 model with some make shift turbo porps. I was thinking that I could modify an edf 40 and make some custom cowling. I was thinking that i could use two small brushless outrunners with a prop on one end and a shaft comming out the other turning an edf.

[fhhuber506771]

Well... the point of a turboprop is to use the power of a turbine engine to turn a prop. The exhaust of the turbine provides insignificant thrust.

so a "sort-of-scale" application that mimics this with electric drive would be to gear drive the big prop... and have a direct drive very small cooling fan for the motor.

Or better yet... just drive the big props (geared or direct depending on motors used, prop size and weight of the model) and use more conventional methods to cool the motors.

*************

Driving the props for the scale Osprey is not the problem... its figuring out the control system to keep it under control through the transition from hover to FF mode and back, rotating the motors 90 deg. The full scale one uses a computer with more power than your desktop machine to keep it from falling out of the sky.

The Raptor would have similar issues... probably not quite as bad... but again... you would be better off direct driving the forward fan SEPARATELY from the rear DF

[rdresch]

The problem is indeed with the props. They need to be a compromise between a heli blade for hover and a prop for forward speed. That said , Tech model products makes a mixer specially designed for VTOL. That will solve all the control issues.
Rudy

[canadian_bacon]

I was thinking of using a makeshift turbo prop mostly for the cool factor, i am not too worried about controll isues yet.