Hey Bruce,
A sear type system such as in rifle triggers would be awesome to implement, but would be prone to dirt etc making it either hard to set, or hard to release...
I am also not 100% wild about r/c servos, I bent my heli's a few times due to servo failures, it started to get quite expensive eventually, we tracked the failures down to being vibration related.... and goodness knows, theres enough shock and vibration on even a smooth running roid!
I have another idea, best described as an over center linkage... 3 or 4 links in series, the center 2 'fold back' on themselves just slightly over center... a small push at 90 degrees will release the links allowing them to straighten out and extend to length, this would slacken the governor spring and the rack would be driven closed... quite simple I think... To reset the linkage, simply fold the links back into position and away you go! What I like about this idea is that there is pretty much zero chance of failure... if it does fail, it fails safe too... The push could be anything from a gentle tug on a piece of string to a quick jab from a solenoid plunger... the release force can be set by how far over center the link rests, so it might even suffice as a type of mechanical vibration detector if set fine enough... Who knows!
Your thoughts?
Cheers
Ed