COMBAT CLINIC Number 3 from Richard Hargrave The method illustrated below is becoming more and more popular and is steady replacing Electronic Speed Control (ESC) devices, which are sometimes expensive and often burn out. There's no magic here, just a straightforward design with simple hookup.
If you follow the wiring diagram, everything should work as advertised. Many different STDP microswitches are available, so it doesn't matter which you use so long as the switch is STDP. The smaller ones have tabs that are very close together, so you will want to add shink-tube at the tabs to avoid shorting out.
Some motors have their polarity marked and some don't. If marked, follow the drawings; if not, use alligator clips to make temporary connections and when you are satisfied, solder it up. Make sure the props rotate in opposite directions, with the top blades moving out (away from center). On a three-shafted vessel, the center prop rotates opposite the outboard props. The outboard props will rotate in the same direction.
Adjusting speed: First try different voltages, then when the speed is close, adjust prop pitch or change prop size (a smaller prop with the sam pitch won't reduce your speed by much.) On the Unryu, the pitch was so flat it was almost invisible.
