Left and Right Motors with additional Rudder

Hi there, so this is my first venture onto the forum and my first venture into ardupilot. I admit it’s not a great combination, please be gentle.

I can almost hear myself asking, “Why are you trying to do it that way?” as I write this but here goes…

If I have two motors, a left and a right, and two esc’s (one for each motor), and a rudder running from a servo, can I allocate an output for each esc and maintain a rudder?

If throttle is on RC3, can that drive two outputs on the board, for example 2 and 3 at the same time?

PS, I know I can wire the esc’s together and run from one output.

I’m looking more as something to do to start looking at customization / development, having a flight mode or similar to allow me to switch between skid steer and rudder or limp home on just one motor should it start to get to hot as clogged with weeds, lose a prop etc.

ServoN_function param will let you set any output pin (servoN) to any output function.
http://ardupilot.org/plane/docs/channel-output-functions.html

Thanks James. I tried that previously and found that I still have to output two channels from my tx for that to work in manual mode. for example, if i set rc6_function to 70 (in addition to rc3 being already set to 70 by default) my tx sends throttle on only channel 3.

So only the esc connected to channel 3 will have output when in manual mode unless i do something with my tx to output 3 and 6 from the left stick input.

What firmware and autopilot are you using?
ServoN_function is different from rcN_function - there’s been a significant rewrite of input/output mapping in the latest releases.