oh man...das an old trick
i did this but replaced the pot with fixed resisters to convert a servo into a sail winch servo.
this is a bigtime mod for the battlebot RC's and i also used it as a horn switch on the revo.
E-revo 3.3 conversion, 249kv outrunner, 6s, MMM
the porthole from the noob world an here has been opened!! that's how i got in.