Been brainstorming ways to reduce/eliminate the inertia from moving two servos.... here are a couple ideas... each has its own set of issues... a couple vids show failure mode with one servo locked up....
http://www.giantcircus.com/Videos/Ru...-02-run-03.mpg
http://www.giantcircus.com/Videos/Ru...s/broke-20.mpg
http://www.giantcircus.com/Videos/Ru...e_servo-01.mpg
http://www.giantcircus.com/Videos/Ru.../direct-01.mpg
http://www.giantcircus.com/Videos/Ru...oke-20-deg.mpg
both systems feature 120 degree servo throw.
the big grey bellcrank is the rudder tillar arm