R/C aeroplanes use ailerons to roll just like real aeroplanes. Sometimes the design of the plane forces the builder to use two aileron servos. These designs usually have the ailerons out towards the wing tips, making it impossible to use a single servo mounted in the centre of the wing. On larger models it is better to have two servos to maximise the amount of torque being transferred from the servo to the aileron. The two servo installation gives the modeler some interesting options that a single servo design does not.
Use a “Y” cable to connect the two servos. The “Y” cable will plug into channel 1 on the receiver. This is the only option for a four-channel receiver.
Center the servo by turning on the transmitter and then the receiver. Now mount the servo arms and adjust the linkage so the ailerons are both level. This will reduce the amount of trim you need to add in flight.
Make sure the linkage between the servos and the ailerons move in opposite directions when you move the right-hand stick on the transmitter. When you look at the plane from the rear, the right aileron should rise up when you push the stick to the right, and the left-hand aileron drops down. (This type of installation can be used with any three channel or more receiver.)
Use a servo extension cable if needed and plug the right wing aileron servo into channel 1 on the receiver.
Plug the left wing servo into channel 5 on the receiver. Use a servo extension cable if needed.
Use your transmitter and enable the aileron differential function. Move the right-hand stick left and right to actuate the ailerons. Use the servo reversing setting, if needed, to get the ailerons moving in the correct direction.
Plug the right wing servo cable into channel 1 on the receiver. Use an extension cable if needed.
Plug the left wing servo into channel 6 on the receiver. Again use an extension cable if needed.
Use your transmitter to centre and trim the aileron controls as mentioned in the four channel installation section. This type of installation will allow you to program in flaperon control. Flaperon control allows the ailerons to work like flaps where both sides move in unison, downward, to create drag. This is used to slow the plane down for landing or give scale planes a more realistic flight speed.
Most computerised transmitters have preset functions that make flaperons easy to program. Read your transmitter manual before enabling this function.
Pay close attention to which aileron is plugged into each channel of the receiver. Installing them backwards will cause your plane to roll in the opposite direction than you expected.