RE: LOGO-10 servos
I have HS 85 servos and these are what I use on mine in my Logo 10.
[link]http://www.servocity.com/ServoCity/Products/Servo_Horns_Arms/Hitec_Aluminum_Arms/hitec_aluminum_arms.html[/link]
The HS 81's are a little weak for the cyclic though. The 85's are about as low as is recommended.
See ya,