Wanted: Ivoprop inflight adjustable props information

[twistair]

Local guy who flies MTOsport with IVO noted that his props' central cylinder beats seriously. Here are some short videos of how it looks alike:
http://archive.ural-gyro.ru/4b74e4f47abd4c68bfbd592251e94d66.avi
http://archive.ural-gyro.ru/027c290b75984f1c88d1563faac3933e.avi
He's asking for any possible information for this cylinder and its contens - drawings, rigging procedures etc.
I tried to search in the Net but didn't find anything worth.
Any inputs are greatly appreciated.

Thanks in advance,

[gyroplanes]

My player wouldn't play either videos. Codec problems it says.

[twistair]

This may be Tom, if your kodek pack is outdated. You may want to try to download&install K-Lite free kodek package (available free in the Net) - it works for practically any video.

[ckurz7000]

Alex, I have a drawing somewhere that came with my Ivoprop. It is a cut through the assembly that shows how it is constructed. Is that what you're looking for?

-- Chris.

[twistair]

Yes Chris, that is. I think I had it somewhere too but failed to find. I'm also looking for any info on the assembly/maintenance/adjustment of this unit. Our local guy was too fast to touch it with his wrenches so I'd like to get as much info about this prop for him.

[bryancobb]

Hey Twist,

Her's a cutaway pic.

The standard IVO just has a stud and jam-nut in the middle. To adjust the pitch on the ground, you loosen the jam-nut and turn the threaded stud in or out to increase or decrease coarseness on all blades.

On the "in-air" adjustable one (pictured), The electric motor with planetary gearbox turns the same threaded stud in or out. You don't have the luxury of a jam-nut or locking mechanism! The friction of the system is all that holds the blades pitched. The torsion in the fiberglass blades wants to naturally put them back to their static pitch.

We removed ours off our Kitfox for 2 reasons. 1) Sport doesn't allow in-flight adjust. 2) It would not stay set after we released the switch. It would CREEP. Almost got in trouble several times on takeoff.

http://i950.photobucket.com/albums/ad350/bryancobb/electricpropsystem.jpg

[twistair]

Thanks for the info, Bryan, very interesting. I'm now shaking my brains trying to chew out how this could be - in your case - that pitch changes itself. I mean that if this would be regular thing then Ivoprop couldn't sell them long. Probably something went wrong from normal condition?
I saw this cutaway picture since it is on their website as well. But I'm looking for the information about internal structure of the servo itself. Found this poor quality pic somewhere, it makes things clearer:

[Rotor Rooter]

Just some speculation;

One possibility is that the vibration combined with force of the elasticity at the blade causes the pitch screw to rotate in respect to the hub..

Another speculative thought is that repeated accelerations and decelerations of the engine may react with the rotational inertia of the electric motor to cause the pitch screw to rotate in respect to the hub.


Dave

[bryancobb]

We tried to understand/figure out what was causing it. I agree that with a double planet, it's hard to see what would make the screw back out.
The threads was perfect and unworn.

The fact is though, we'd fly around say...30 minutes. The RPM would creep up. Then if we tried to do a touch-and-go without readjusting the prop, it wouldn't climb, and the RPM would be at redline.

[bryancobb]

... I'm looking for the information about internal structure of the servo itself...


It's simply the guts of a rechargable drill inside the housing that turns the pitch screw.

[Rotor Rooter]

I lied in post #8 above. :(

It is the Worm & Wheel that is theoretically impossible to back drive at a ratio greater than 10:1.

Error removed.


Dave

[ckurz7000]

Alex, I have the complete documentation (6 pages) on the Ivoprop, but it won't let me upload because of filesize (1,5 MB). Can you PM me with your private email so that I can send it to you?

Greetings, -- Chris.

[twistair]

Yes Chris, my e-mail is protor@yandex.ru

Thanks in advance, that would be priceless!