Right, to end all my issues with my heavy throttle, I have designed a servo to drive the governer.
It ridiculously over engineered, but it now means that my throttle can be tweaked for travel and sensitivity. Its also very very light.
It required a very very powerful servo, as it essentially being stalled. I ended up using a Tone PS050 designed for very large model aircraft - 4-6meter wing span.
a 12v - 8.6v regulator supplies power to the servo, and a servo tester interfaces a sliding Potentiometer with the servo itself.
Took a bit of testing. Firstly, I measured the force required to pull the gov lever to 100% with some luggage scales. 3.2kg/cm
Then I bought a much smaller servo, rated at 20kg/cm. Turns out, this is the max amount of weight they can move, they cannot hold this weight without going pop, as I found out pretty quickly.
Bought another one with all metal gears, ball bearing drive support and that one also went pop. Luckily this happened during testing.
Then I pushed the boat out and bought this PS050 - Max torque at 8.4 volts, 104kg/CM. It has a rated constant torque at 100% duty cycle, of 15kg/cm. More than enough to sit at full throttle the whole time.
The linear pot was the most time consuming part of the install. I spent aaaaaaages trying to get a rotating pot to work with the cable, in the end I just went to maplin and got the linear pot and stuck it in a old plastic screw driver bit holder.
I am going to setup the left hand lever to the decomp lever just in case it gets stuck on full throttle for whatever reason.
