RE: DC Motors As Servos
Using RC-car boards is a trade-off, Price vs Longevity.
I remember during my Stingray conversion, I had the WTC and boards all insulated well (I used a balloon to keep the board dry, space was a problem). However, just as everything seemed right, a transistor must have blown out and the whole board poof![:@] I'm no expert in circuitry so I've never really gotten to fixing the thing. Since then the Stingray project pretty much went belly up.[&:]
@Crunchy: I'm not sure if you can find any cheap RC-car boards that carry the 75Mhz frequency, since most hobby-grade equipment use it. Radioshack cars mostly run on 27 or 49mhz. The RC-tank boards I posted on the other thread seems to be pretty reliable, as long as you add a heatsink and cool it well. A never version is available via a dealer in the US, the transmitter should be compatible as long as you use the same crystals.
The bellows GreenAce mentioned do their job well, I bought a set myself to use in my U-boat.
Hope everything works well!