Edwin

My Feedback: (2)

I'm thinking about using a torque rod to connect the 2 elevator halves together on my TF giant P-47 and using a futaba S3305 (~99oz). Has anybody done this? Is 2 elevator servos really any better (piece of mind or whatever).
Edwin

js3

My Feedback: (3)

If for no other reason, two servos provide redundancy. If one servo fails and you only have one servo, you've lost 100% of your control surface. If you have two servos, you've only lost 50%. That second servo may save your plane if the unthinkable happens.

JGrc

My Feedback: (29)

Edwin,

For years I've using an 3/8" aluminum rod with steel pins on the elevators and a 6/32 or 4/40 thread rod connecting the pushrod link. You can always connect 2 servos in tandem together for redundancy regardless of the linkage you use.

JG

carlbecker

My Feedback: (3)

I am not sure you get useful redundency with two servos. If one fails anywhere but trimed neutral I would thing it would be a handful. I would guess flapping in the breeze would not be uncontrolable though.

js3

My Feedback: (3)

Indeed, I imagine it would be quite a handful even if the failed surface was trimmed neutral. That's why I said it MAY save the plane. Still, I'd rather have SOME control than none at all. Even if the crash means a total loss, having some control might allow the pilot to direct the crash away from spectators. That's always a good thing in my book.

Peter_OZ

My Feedback: (1)

Edwin,
good arguements for both cases. In my view though you would be better having each half independant of the other on it's own rod and servo. The big 3D planes seem to be set up like this so guess they know athing about these setups.

I'm building the same plane and kit as you and I will be using the splt elevator setup though I will be using bolted ball links at each end to remove any slop and provide a bit more security to the linkage.

On my P51 in the pic attached you will note the 3/8 alloy rod going down to the elevator. The ele halves are joined via torque rod. The 3/8 rod in turn connects to a disc thing you can see in the centre, it is on rails so it can slide back and forth. 2 x JR DS559 connect to the disc and if one servo failed I still get hald elevator travel which is enough to recover the bird. It is an excellent setup and I wish now I had done this for the P47.

I will most likely do it for the Corsair when I build that.

cheers
Peter

the-plumber

All the servos I ever had fail in flight had stripped gears, and in that condition represented no load whatsoever to the other servo.

OTOH if the servo motor dies then all you have is the gear train load, and the other servo can easily handle that.

I only build scale models, so most of my elevator and rudder control systems are hidden, meaning paired servos using one push-rod or pull-pull setup, and on split elevators I always use an aluminum arrow shaft to connect the elevator halves, with the horn clamped onto the shaft. Never had a failure with that layout, whereas I have had elevator failures with only one servo.

SeaHawk-RCU

Peter,

Here is a lovely pic of your P51 at the LARCS warbirds day last Sunday.

Col

Peter_OZ

My Feedback: (1)

Hey col,
thanks for that mate, wonder if that was before my nerves started making the right thumb go twitch twitch!

Got any more in high res?

cheers
Peter

SeaHawk-RCU

The piccies are from Bob J. our club imageographer. I have the following in 800 wide but Bob is going to burn the originals onto CD for me. will send when I have them.

Check the video and photo section of the LARCS site for more pics. www.larcs.com.au

Sorry I didn't get to say hello on Sunday. Caught up with the chimp though. Recognise yourself in the group shot?

Col

Peter_OZ

My Feedback: (1)

Gday Col,
thanks for that. Nice pic of the rotation.

will check out larcs website too.

sorry meant to say gday to you as well. Missed out on the group pic.

cheers
Peter

sebo

Look here...it may be of help. Saw it on another post. http://www.sierragiant.com/prod14.html