Torque rod on elevators
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RE: Torque rod on elevators
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.
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RE: Torque rod on elevators
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.
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RE: Torque rod on elevators
ORIGINAL: carlbecker
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.
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.
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RE: Torque rod on elevators
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
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
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RE: Torque rod on elevators
ORIGINAL: carlbecker
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 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.
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.
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RE: Torque rod on elevators
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
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
#10
RE: Torque rod on elevators
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
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
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RE: Torque rod on elevators
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
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
#12
RE: Torque rod on elevators
Look here...it may be of help. Saw it on another post. http://www.sierragiant.com/prod14.html