First P-51 and would like to finish her off right... So here's my problem. She takes 9 servos.
1- Throttle
1- Gear
1- Stab
2- Elevator
2- Flaps
2- Ailerons

I have a 7CAP, and plan on Y-ing the Elevators (Yeah I know trim on one channel only).
I also wanted to tie the flaps together, but don't like the idea of having the horn offset on one side of the wing for that flap.
Then there is the question of CROW, Do I need it. The plane is a Black Horse and plan on throwing a .75/2c at her for some authority. (.61/2c-.91/4c) with a pitts.

So, do I lose seperate ailerons or flaps (and have one of the flap servos -100% so I don't have to offset the control horn)?

Thanks

Ok, first, get the crow idea completely out of your head.

Second, don't worry about the horns on the flap servos. You will never see them. They are on the bottom of the wing, and once airborne, they'll be too small to see.

I can relate to everything you're worried about - I go through the same thing with every plane I build. But something I have learned to deal with is...

Don't sweat the small stuff!!!

It seems like every time I jump through hoops to make something complicated out of something that should be easy, I wind up getting bit in the end.

So do it the simplest way possible - that way there's less to go wrong.

Someone correct me if I'm wrong here but I beleive the elevator and flaps will require the much more expensive reversing Y harness to operate correctly. If you have the 7th channel I would recomend NOT Y-ing the elevator so you can trim each elevator half seperately and get them perfect. Any roll tendancy from applying up elevator on this plane could be the death of it at slow speeds... Like landing[:@]

I have a FuntanaX 100 but only have a 6 channel TX so I had to use the reversing Y on my elevator and mechanically adjust it. It works well but the manufacturer does not recomend this. They recomend a 7 channel computerized system.

You can just put the servo arm on the other side of the servo to mechanically reverse it. If the placement for the elevator servos makes this difficult, then it's probably best to use the extra channel there, and then use a Y-harness for the aileron or flaps, since flipping the arm to the other side on those servos is usually quite simple.

Instead of a reversing Y, you could also use a futaba (or clone) servo on one side, and a JR (or clone) on the other. Since your flaps only go down, your servo arm's neutral would be at either 100% or -100% depending on your configuration.

You don't even know WHICH P-51 he has or how the servos can or should be connected or even where they are mounted. A lot of assumptions here. I assembled a Seagull CAP the other day and the way the servos were laid out they required nothing more than a simple Y-cable. And both elev servos trim identically of course since Y'd.

Lots of WAG's in most of these replies since the details are unknown.

Oh yeah, NO Crow.

Yes Bruce you are correct. I am assuming it is set up similar to something I have or have had. It very well may be designed differently.

To the original poster: Perhaps you should take this question to the warbirds forum and tell them which P-51 you have and ask them this qestion. Odds are pretty good someone has had the same plane.

Thanks for all the advise... I'm going to check out what's up in the warbirds forum with this. The P-51 is a Black Horse which I mentioned in the original post. I will be trying the two elevator servors together. That will leave me with 3 channels for flaps AND ailerons. I've run into this problem before on a 4 channel and 2 servos on the tail, y-ing them was just fine. I had to take few runs to get them to be sync'd 100% but they were OK on the maiden.

BTW, Black Horse's instructions suck moose balls, but the quality of the builds are really good. FWIW!

http://www.philshobbyshop.com/tek9.a...fic=jmppipini0

I just found this post. Your P51 and my P51 are similar in regards to servo requirements. Mine has x2 ailerons, x2 flaps, x2 elevator, x1 rudder, x1 throttle, and well x2 for gear. I'm running it from a 6 channel radio. For ailerons since the servos are physically installed reversed from each other a standard servo y-connector works well. However for the flaps, elevator, and gear I needed a reverser. Instead of using the reversing y-connector, I used a Futaba SR-10 servo reverser one for each of the flaps and elevator. And a servo synchronizer for the gear with its own power input. This allowed me to trim each half using only a 6-channel radio. After I finished the installation, I realized how much more simplier this would have been if I had a radio with more channels. But it works and it works well.