Originally Posted by
Gregor32
I have been building a cmp 140 mustang for a number of years now and finally finished it this weekend. It has a magnum 180 fs which gave me a bit of trouble initially but is running great now. During this time the motor was running very roughly and I noticed one of my ailerons was not moving smoothly and upon inspection it had stripped the gears around the neutral position.
I continued with my tunning and then noticed the same from the other aileron, so now both aileron servos have failed in the same way. and yes they where fine before, what would be a good servo to replace these HS 635hb as I don't trust them now?
thanks Greg
The problem is not with the servos' but the 4 cycle engine. If you research mounting techniques for installing this type of engine you will find they recommend soft mounting. This method is to negate the negative power stroke that induces extreme vibration level in the airframe. I found this out after numerous servo arm screws had backed out from the output shaft of the servos. Using locktite solved this problem but not the vibration. The gear train in your servos suffered from this problem.