i'm a heli pilot but i've recently built a couple of trainer planes. my latest build is an ultimate biplane. i've got everything ready to go except the aileron servos. i'm wondering the best way to mix with my radio (dx7) or mechanically set the servos up to work opposite each other. any advice is much appreciated. thanx

If you have one servo for each aileron, a Y Harness is the easiest way. As for your push rods, they both need to be on the inside of the servo wheel or the outside of the servo wheel. Install a Y Harness and plug the Y Harness into your receiver and you should be good to go. Good Luck, Dave

With a DX7 you just put one servo into ch 1 and the other in aux1 and actavate. Follow the instructions on the radio. If I don't have to I never use a Y. I have had them fail on me more then once.

Just remember, if you hook it up to 2 seperate channels in the reciever and the alerion direction is backwards, you must reverse the alerion channel and the aux (slaved) channel too, otherwise, they will bolth be moving the same direction.

I agree with DavidAgar. KISS (keep is simple silly) comes into play here. Hook up the servos to a Y-harness. Then hook up the pushrods to opposite sides of the servos for proper operation.

Ken

Try to get your total movement correct mechanically

Do not rely on a computer transmitter to correct your mechanical errors

And my question is, why would someone buy a computer radio with all these great features? Sort of like going back to wearing bow ties and high button shoes?? I bought my radio to get away from these old school set ups and have the mixes to use. The DX7 has the duel aileron set up in it's program but you have to use a Y on duel elevator servos. A Y harness is something we did before we had these nice radios with all the great features.

If you don't have your servo linkage set up mechanically with the correct maximum travel in each direction, you are destroying your resolution capability when you even it out or reduce it with the computer.

Computers are mighty nice though. I like high rates with a lot of expo. It's a real hoot at times when you are in the mood.

I like to be able to slave the second elevator servo to the first with the variable to get them to work the same or to correct aileron servo differential travel volume to allow for adverse yaw.

Slaving a little rudder in with the ailerons is nice as well as a little elevator with the flaps

thanx for all the advice guys. i'd like to do without the y harness if possible. i've setup several helis in my dx7 but never a biplane. i have everything mechanically setup but had one in the ail. channel and one in aux 2. i'll switch to aux1 and enable the dual ail. function . as it is now one servo works like i want it and the other pegs out in one direction. i just wasn't sure what channel to get it on and how to set it up. mixing the ele. in was my next question.

There are some basic principles here brought by w8ye and Gray Beard. Bassically you need to trim mecanically all of the the servos in the plane, then start with the computer adjustments, that will avoid to override any servo which easily could run out of the safe range.

flaperons is the best way i think...allows better adjust if one of your control rods is too long or too shot without having to screw the bit about. with flaperons you can just trim it with the radio. i had a y harness and about 2 flights in i got rid of them and used flaperons - plus i get the benefit of flaps from the ailerons to slow the plane down quicker

i have mechanically trimmed everything so that i don't need any subtrim in the radio. (or very little) i just wasn't sure what channels to use and how to mix them in the radio. i have everything mechanically perfect. i've setup travel by using the aileron channel for both ailerons one at a time. mechanically i'm happy. i've been reading in my dx7 manual how the best way to setup would be and i'm going to try the flaperons first. this will give me seperate trims and travel adjust for each servo. i started cleaning my shop up and haven't even touched the plane yet today. will let you guys know later on how it's working. thanx for all the tips.

I think in your radio it has to be the flaperon set up, been a couple of months sense I set up a plane with the DX7 but with duel aileron servos as I recall it was a must do thing. I set up a couple of students with the DX7 and end up doing there aircraft set up for them, there is one step I always forget to do and it bitesmybutt every time. The instructions are a little lacking in that set up or I just keep missing it? Probably just me, just too many radios, mine is a lot easier to use.

you are correct. i tried setting it up by the instructions and they are totally lacking. now i'm more confused than ever. anyone have a dx7 that might be able to walk me through a basic setup. like i said mechanically i'm good , i just need both servos working opposite when i deliver ail. input. the way they have to mount in my wings at this point i'm limited to one mounting option. thus the need to get them going opposite directions.

That's the easy part, you just go into servo reverse and change one of them.

i know how to change direction of the servos. i just don't know how to get the two channels working with the same input after plugging one in to the ail. and one into aux1. if i can get them working i can reverse them to the right direction. it's the flaperon menu i'm having trouble with.[sm=confused.gif]

i appreciate all the help guys. just wanted to update. i went ahead and figured out how to flip one of the servos in the wing. just mainly wanted to simplify. all is good now and i've also got the 4 stroke .52 magnum all tuned up and ready to go. she is ready for her maiden. i put a pic in my gallery but can't figure out how to post it in the thread.

w8ye,

That plane is just awesome looking. . . . . . . . Yeah, one of these days. . . . .

Jack

I have a couple airplanes with dual aileron servos and dual elevator servos in my DX-7.

You can use any free channel which is generally aux-1 or aux-2 or even the gear channel.

Sounds like you got it working but I'll go over how I do it.

If memory serves me right, you first have to disable the switch for the channel you are going to use. Then you turn on a one of the programmable mixes and mix the second channel with aileron. You can select the percentage of mix for both aileron stick directions, generally 100% is what you want of course. You can also fine tune the end pints to make sure both surfaces do exactly what you want.

I'm headed out to the hardware store and to grab some dinner right now but I'll go into the menu on a plane a little later and make an exact list of the steps.

I only do this on larger planes though. for .40-.60 sport planes I figure a Y-harness is good enough.

If you do it Chuck I will print it and keep it on file. That's the only radio I use then bites me every time.

Well, maybe it's the Monokote fumes or all the fun that I had in the past but my memory is just fried. I looked at both my Sukhoi and my Yak and both have Y-harnesses on the ailerons. I would have sworn that at least one used separate channels. They do use two elevator servos on separate channels though which is sorta similar.

First thing I do is go in the flap menu and make the flap switch inactive. Then I mix 100% flap to elevator in both directions. Reverse the flap channel if necessary and that's it.

Is it the right way? Probably not but it works and both planes manage to fly OK.

I'm currently putting together a 27% Extra-330 and I'll be sure to do the ailerons on separate channels. I'll post how that goes.

thanx chuckW. i appreciate the help. i'll probably experiment with the setup on the dx7 after the maiden. mainly want to learn my radio better. i haven't been using the dx7 long so i'm still playing with it. i thought the same way being a 40 size i figured the good ol' y harness would do fine. Good luck with the Extra. thanx for posting the pic w8ye, that's my newest toy. it's a magnum .52 rfs with a 12x6 , ar7000 rx, futaba 3003's all around and jr nimh batt. gotta get her in the air.