MinnFlyer
Posts: 19353
Joined: 4/22/2002
From: Willmar,
MN, USA
Status: offline
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Noah...
I used to be a machinist for the government and considered this project for many years. I had lots of high-tech machinery to make any parts I needed, but still I scrapped the project due to the many problems involved. Some of my conclusions were:
Use a single engine mounted in the fuse: this way there's no chance of a one sided flame-out.
Next: use two, helicopter rotors. let's face it, you have to be able to hover this thing as the rotors are too big for the plane to land in a rotor forward configuration. And if you're going to hover, there's no way to balance your plane without a rotor head. If you don't believe it, consider this: You have two propellers that lift the aircraft off the ground to a height of , let's say 3 ft. And by some miraculous luck, it is balanced perfectly fore and aft so it doesn't tilt. Now, you want to transition to forward flight, so you start to rotate the nacelles forward, but there's a problem... remember those two spinning propellers? There's another scientific term for them... GYROs. That's right! Those propellers are acting like two gigantic gyros, and they don't WANT to be rotated! But! Remember that miraculous balance? That means there's no problem tilting the fuselage, so... when you try to rotate the engines forward, what will actually happen is that you will tilt the fuselage nose-up.
Let's go back to that perfect hover, now a little breeze blows and you start being blown backwards, what do you do? Rotate the nacelles forward? As you now know, that will only tilt the nose up exposing more of the fuselage to the wind, and before you can say "There goes all my money" the plane is in little pieces on the runway.
No, my friend, under NO circumstances will two propellers work. You MUST have two rotor heads.
Next: If you don't already have one, be prepared to shell out big bucks for a very sophisticated radio. Think about it... In hover mode, the collective (changing pitch on the rotors for more [or less] lift) would be controlled by the throttle (to go higher) and mixed with the aileron (for lateral balance) and the elevator servos will actuate the forward and aft rotor control. But once you transition to forward flight, the actual ailerons on the wing must now be controlled by your aileron stick, and your elevator stick must now control the elevators and not the rotors.
As I said before, this was a pet project of mine for many years, and the more I thought about it, the more bugs I encountered.
I'm not saying that modeling one of these babies is impossible, but don't forget... The military scratched this project because there were too many problems with making this thing fly. Don't think you're going to stick two engines on an airplane wing and show them up!
_____________________________
Mike B.
AMA# 42400 www.gettingairborne.com
"Those are my principles. If you don't like them, I have others." - Groucho Marx
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NEED HELP!!! Scratch-building a V-22 Osprey - 
