For my 5th plane I am assembling a P51 arf. I chose this plane for the new building and flying challenges and so far the challenge thing is working

The plane has a split elevator with dual servos, up to now I have only set-up split elevators with a single servo. Can anyone offer any set-up tips for the dual servo arrangement?

Thanks

There are a couple of ways to do it, the easiest is to use a jr. servo on one side and a futaba servo on the other. Next comes useing a "Y" connector with a built in servo reverser or a matchbox arrangement. The best way is to plug into 2channels and mix 'em together useing your radio. 'Course you didn't mention what type of radio you had.........

Ok Cstevc, you got me on that one. Tell me why a JR on one side and a Futaba on the other ? I have installed many many systems useing same same on both sides.
Hill202, if you have a computer radio I'm sure the manual will tell you how to use another channel and mix them instead on the Miracle "Y" reverser.

I am using a JR 7 channel ( xp783 )

I'll need 6 channels. There's not enough to use seperate channels and mix. I guess I'll have to use the reverse "Y". Are they reliable? Will the servos be in sync?

Thanks

sorry for replying to myself, miscounted channels

I think 7 channels is enough

elev - 2
rudder - 1
alieron - 1 (reverse Y ) ?
flaps - 1 ( reverse Y ) ?
throttle - 1
gear - 1

previously on a ultra stick with a quad flap set-up I was using 2 channels for flaps and 2 for alierons,

Will your radio mix for odd channel arrangements? Remember channel 5 is landing gear or flaps, and six is used to split your ailerons. so that would leave channel 7 for your mix. You can use just a normal y connector and place your control linkages on opossite sides, use the most distant servo on the bottom and the nearest on the top. I did the only place in the servo movement where there is any difference is at the extremes. Reversing servo set up is very easy, but you may find yourself picking up piece like I did, when it failed in flight. Have fun!!!!

C'mon now, I'm still waiting as to why you use one Futaba and one JR servo.
Don't leave us all guessing. ??????????????????

tommy s

Because they are reversed in normal throw.

I've never used Futaba servos except for retracts, but they could not possibly
travel at the same speed as the JR servos when going to instant full throw!
All JR servos don't even travel at the same speed.

tommy s

I guess matchboxes are the way to go, of course I have a few questions about them. I'll take those to the radio forum. I should just buy a 9ch radio

Your right Tommy, tell them about it.
AND woo the hoses, just for the fun of it,[sm=confused.gif] I got a JR and a Fut and set them up on a Y, like you would do for ailerons and guess what, same same ? Did the same with a JR and a Hitech, no difference, did it with a Fut and a Hitech same. Even did it with a Tower Hobbies and a Futana So whats the deal ? I allways knew my JR raido was screwed up but---------------------------???

Speed in thousandths or ten thousandths of a second, would make joined surfaces a millionth of inch out of position. So much for everyday flying, So sorry, I forgot you all are international RC champs and need the such accuracy.

Well if you want your split elevators moving at different speeds be my guest,
go ahead. I just don't see any need to use two separate servos to control split
elevators when it is so easy to hook them together with carbon fiber pushrods
especially when JR makes the 8611 servo which is standard size and puts out
almost 260 in ozs of torque and only costs $116.00 which is less than two of almost
any kind of decent servo. I don't know about you but these things are hard enough
to trim without dealing with controls that aren't moving together.

tommy s

PS: Oh, I'm not an Int'l Champion but I've won my share of pattern contests.
I even won in your fair city of Corpus Christi at the Naval Air Station , although
more than just a few years ago. Even got my picture in your newspaper.
I trim my planes to fly straight and true and do what I ask it to do , not just fly.

Servo reversing "Y" connectors, are they reliable? Well, I know of two flyers that lost an airplane due to failer of these connectors. Reversing failed and the elevators went in opposite directions. Of course they crashed. A lot of these are in use so these two could have been a fluke. Myself,I don't use them. I use two channels in the receiver.

I still have alot to learn about mixing. So the 7 channel will not work, right?

Sorry but I'm not the one to answer that question as I've never used two
servos on elevator and don't like that set up. To get the best advise you should
go to the RC Radios,Receivers,and Servos section of this forum (Forum Home)
where your questions will be answered by factory representatives from all the
major radio manufacturers.

tommy s

You will not need a reversing 'Y' for flaps, you want them to move in the same direction i.e. both down at the same time or both up at the same time.
Why 2 channels for elevator??

The reverse Y cables wouldn't be needed.

You hook up the ailerons witout the reverser every time.
The flaps can be hooked up with one side's control horn just a tad outboard of the other side's... and then no reverser is needed. the discrepancy of the control horn being out 1 to 1.5 inch will have no effect at all on a plane that is large enough to need dual servos for the flaps.
(or you have the one servo mounted a bit further outboard than the other and you need 1/4 of a penny to latterally balance the thing.)

True on the flaps and on ailerons you place the control links on opposite sides. but instead of using a y to channel one. You can split the ailerons between right aileron on channel one and left aileron on channel six and set your radio for flapperons. Elevator with two actuating servos, set up many different ways. So as follows:

Ailerons on one and six.
Elevator on two and seven or eight if slaved.
Throttle on three
Rudder on four
Gear or flaps on five

Thats 7 channels, if you are using JR the channel numbers are different for ailerons and elevator.

yes but I need gear and flaps

received the following from Dan Snyder;

Sure, the 783 will work fine with that plane. You will need to use 3 Y harnesses or matchboxes, as there are 10 servos in the plane and you have 7 channels.

_____________________________

Thanks!
Danny Snyder
Team JR
Horizon Hobby
Product Support Technical Manager
[email protected]
www.horizonhobby.com

Well Mr. Hill,

You should talk to Mr Synder, as to which JR radio can reassign channels to specific functions. Looks more and more like the 8103 radio to me one step below the 10x. JR10x will definately do that and more.

OOOOooooo somewhere I missed thinking about the 10 servos issue...

An option that should be considered with that much load... dual Recievers. You gain some significant safety from this.

In case one RX fails, there is a high probablility of being able to save the aircraft. If you can't save it... you can at least steer it so the impact is in a safer location and possibly minimize damage.

You split the RX loads and thus take load off the switch harness . (one of the weakest links in the RX power system) With just 5 servos per RX... and thus 5 per switch harness you have appx 55% the current demand on the switch.

You would automaticly be using a form of dual battery system. If the rolls became imballanced, or significant roll coupling occurred with elevator, you would KNOW one RX's power was failing and still have a good chance at successful landing. (rather than... Uh-oh, sluggish elevator... oops no control at all...[:-] SMACK! )

There was a series of tests on dual RX systems done a few years ago... the test plane wa set up such that one RX could be shut down by switched channel on the other RX. (unused on the RX being sht down) He put the sticks in the coners, and shut off the second RX disabling 1 elevator half and one aileron (among other things) at full deflection. He then safely landed the model! Choosing the surfaces to be controlled by each RX was the key to that success.

H.Wayne & Tommy, Jr servo's and Futaba servos actually rotate in opposite directions. Personally I have never used this method to do the dual elevator thing but an old friend of mine did it on his U-can-do 60 and the plane flies just fine.

I use Hitec servo's myself and have the programmer. I just set up my servos on the programmer and then use a Y connector or else use the Ailevator function in the 9C.

Here is the best way - get a smart fly equalizer. I just picked one up for my Cap X. You plug two servos into the equalizer and you can match the throws and end points of both servos. This is better than mixing it in your radio or "Y"ing them into one channel. The equalizer will exactly match the servos - it's almost as if you had one servo.

http://www.smart-fly.com/page2.html