RE: Pull-Pull on throttle
 

I'd agree for sure with this. But interestingly, on a different thread regarding optical cut-offs, one veteran gasser flyer has said he plans to keep the return spring on from now on, just in case of linkage failure. Not sure if the spring can pull a 'dead' servo, but if it can perhaps he's also guarding against a failed servo.

RE: Pull-Pull on throttle
 

I fly mostly gas and have for the last twenty years. I have not lost a throttle servo to motor or circuit board burnout from pulling against the throttle return spring,
What I have had happen multiple times is failure of minature servos when being used on throttles.
The brand did not seem to matter, they just do not appear to be strong enough internally to resist the level of vibration found in gas engines.
My experience is that excess wear or outright failure will come from vibration well before current draw takes out the throttle servo.

RE: Pull-Pull on throttle
 

It could even be argued that the wire method suggested by John would reduce the vibration load on the throttle servo.
The tension on the throttle spring is absolutely minimal. Any decent 5Kg servo will handle that without any difficulty or excessive current draw

RE: Pull-Pull on throttle
 

This begs the question if it would be good practice to replace a throttle servo after "x" number of hours in service? Condsider vacuum pumps in full scale planes: even if working properly at the time, usually they get replaced after 400 hours, or whatever the manufacturer deems to be the service life, since they are failure-prone and when they fail it is with little or no warning. Should we treat throttle servos the same way? And are the flight control surface servos as vulnerable to vibration-induced failure as the throttle servo? Perhaps not, as they do not have a direct connection to the engine like the throttle servo...just thinking out loud :D

RE: Pull-Pull on throttle
 

I lost a throttle servo back in September. It locked up tight, so the spring would not have helped me at all. I am guessing the motor burnt up and froze. It was a pretty old servo. The worst part was that it stuck in a position that was too fast to land, too slow to fly.... It bunny hopped all the way down the runway to the beanfield, no damage to my 1/4 Scale Wilga other than bent axle.

I disconnect all of my springs, I leave the spring there, just unhook it.

RE: Pull-Pull on throttle
 

I have brand new servos on all controls. Best insurance I hope. Capt,n