ORIGINAL: paladin
Assuming the spoiler worked in unison with the flap to allow air through the glycol cooler and when the flaps come down it follows. To accomplish this I will probably install separate servo for spoiler. But have no idea how to work out the slaving/mixing on a seven channel rx, may have to spring for a 9 channel rx.
Joe
You can use a JR matchbox to run all 4 flaps on channel 6(if a JR radio) and then use channel 7 AUX2 for the spoilers on a normal y-harness as I believe this is the set that has the servo covers the same.
Channel 1: throttle
Channel 2: ailerons(y-harness)
Channel 3: elevator
Channel 4: rudder
Channel 5: retracts
Channel 6: flaps(matchbox controlling 4 separate servos each can be set individually)
Channel 7: spoilers(on own servos separate from flaps) regular y-harness
You can then, if you wish, use one of 6 mixes to make the spoilers move up or down in conjunction with the flap switch or leave them on their own switch.
Viola. No need for a new 9 channel tx, although its nice having one.
I had to buy one a while ago due to my B-25 and having separate engine throttle servos, etc. while still being able to have bomb drops.