I did some more work on my servo controls for the Protothrottle over the holidays. I wanted to fine tune the live steam mode a bit more and clean up a few bugs. There are three servo modes- couplers, ESC and Steam. In the Steam Mode, Channel 0 is the throttle, Channel 1 is the direction. Both of these follow the direction and throttle controls on the PT. You can adjust high and low limits and reverse each servo. Here is a screen shot of my programmer:
The electronics are very simple, one board and a 3.7v lipo.
Here is a quick video of the servos on the bench:
Here it is fired up and running outside:
And a video of a complete run around the layout loop: