Brettski:

As it turns out upon closer reading of the literature about the servo driver, it does indeed require a separate 4 cell battery pack to power it. I'd use 4 or maybe 5 AA or D size cells and put in an on/off switch.

The battery powered servo tester sends power and position data down our previously discussed extension cable to the servo and causes it to move, just like in your model airplane setup when you a fun-lovin' youngster.

I've flown model airplanes in -20 Celcius weather and while slow and unhappy, they did indeed operate. I've also crashed airplanes in the same temperature too. These same servos were used in the large C band satellite dishes to operate the antenna polarization controls down to -40 C. Mind you, next to zero load on the servo to just flip a small length of wire 90 degrees inside the feedhorn.

The torque rating of the standard servo is 42 ounce-inches. In other words, will push or pull 42 ounces if the servo arm is 1 inch long.

Extending the servo arm so it completes a 2.75" arc may cut that value down by more than half ... which should still be more than sufficient to move the choke if it moves as smoothly as you described. Some of those large model airplane control surfaces can have significant loads on them at high speed.

If the "standard servo" isn't enough power, bigger servos are available, or it could be run from your 12 volt gen-set battery through a voltage regulator to get down to 6 volts, which is generally considered to be the "practical max voltage" for these servos. I don't think that is needed though and the wiring becomes a little more complicated.

I suppose in its most simple form, you could just have return spring on it and run a length of binder twine up to the house, run it through a window and you pull it to bring the engine into full choke position and let out line as the engine warms up.....

Anyway, looks like you've got no shortage of suggestions, if I can be of any more help after you've made up your mind, just whistle! Happy to help.

Lee

Last edited by Lee Smith; 03/14/08 01:49 AM.