The only time I have ever had a problem with Karbonite gears is when I did not know any better and used blue loctite on the screw. Thank god it was on the choke servo. The loctite took about 10 minutes to eat through the gear set.

I use the Hitec 6965 Karbonite servos on all of my throttles using the included metal arm, but on the throttle there is really no load. They are a .08msec servo on 6v so they are very close to real time and I learned a long time ago a fast servo on the throttle is a real pleasure.

I have used Karbonite servos on larger glow planes with no bad problems. I wonder if using a metal servo arm could strip the gear??? HHMMM????