On a kit, such as the BTE Venture 60, that has the option of a single servo operating the ailerons via torque rods, would it be better to use a servo in each wing or two servos in the center, each operating only a single torque rod if i were to convert it to a two servo setup? Boy, what a run-on sentence.

BCP

use the one servo in each wing. saves the servo from over stress.

It's really up to you. For many years we always flew with one servo in the center. The trend now is to use two, but that doesn't mean that one doesn't work.

To answer your question, I'd place the servos further out on the wings and use a direct rod to the horn. Using the torque rods only introduces a couple of extra joints where slop or failure can occur.
Dennis-

Another really cool thing you can do, is to add the torque rods, but cut the ailerons about 5 or 6" from the inboard end. Use the torque rods to operate Flaps while a servo in each wing works the outboard ailerons.

Another really cool thing you can do, is to add the torque rods, but cut the ailerons about 5 or 6" from the inboard end. Use the torque rods to operate Flaps while a servo in each wing works the outboard ailerons.

That sounds like a great idea. Which would work better, flaperons, or separate ailerons and flaps? If I used separate flaps, would I need two servos? Or is there a way for a single servo to drive two flaps like that? Thanks for the idea.
BCP

BCP:

If you make the flaps and ailerons separate you can use a single servoto drive the flaps, but if you go for flaperons you'll have to use four servos on the wing.

Bill.

Well, if he decides on flaperons, there'd be no reason to cut the existing ailerons.

If you decide on seperate flaps, just tie both torque rods to the same side of the center servo with a "Y" shaped pushrod. (You may have to play around a little so that one flap doesn't drop more than the other.)
Dennis-

What are the pros and cons to each setup? With separate flaps and ailerons, there would be an extra servo, but it doesn't sound like that much more weight will affect the plane. Would any performance be lost if the ailerons were that much shorter? Thanks for all the help so far.

BCP

BCP:

First, generalities.

When at speed flying on the wing, the outer portion of the ailerons do 90% of the roll control. At lower speeds using engine thrust to hold the plane up, or doing 3D, the inner part of the ailerons exposed to the prop blast, does the job.

With a four channel radio you have no flap option, and a single aileron servo operating through torque rods works fine.

With a five channel radio the 5th channel is usually just a switch, normally for retracts. If this is what you are using, a single flap servo is fine, the flaps will be either zero or full travel. No 3D since you wont have inboard ailerons.

A six channel radio, non computer, can have either proportional control of channel six, or a switch, often 3 position. If your tx has just the switch, or no mixing capability, again, one servo. But this time you will have either one or two extended flap positions, or with propo, flaps at whatever extension you want. But still no 3D.

With six or more channels and mix capability, your options are greatly expanded, The first, and most commonly used, is flaperons. Now you are back to having full span ailerons, and 3D is again a possibility if you use a separate servo for each 1/2 flap, four wing servos total. And the inner parts will still work as flaps. Another popular set up is "Quad" flaps, the normal flap portion is deflected full down, and both ailerons are deflected full up. This is also referred to as "Crow," and vertical dives can be spectacular. Very few six and seven channel radios are capable of doing crow, but flaps and flaperons are available. Most eight channel radios will do it.

The simplest is a single servo for the ailerons, next is still just two servos, one operating the flaps through torque rods and the other operating the ailerons through linkage. And on up to the use of four servos, one for each moving surface. You have to decide how complex or simple you want it.

But it would be foolish to do a four servo install if your radio can't handle it.

Hope this helps.

Bill.

Aside from 3-D flying, seperate flaps/ailerons are much better. I have used this configuration on several planes, it works great, and the amount of aileron loss is not noticable.