So, I think I finally have the brain for the $50 robot. But it has left me wandering about choosing a battery for actually running the whole bot. I have it wired up so that it relies totally on the 9-Volt for power, even though I have a battery pack. Is it worth it to desolder and simply attach the battery pack? It says in the tutorial that your overall power 'could be several amps' and I don't know how well a 175 mAh battery is going to stand up to that.
Also, I had an alternative method for modifying servos that I strikes me slightly more robust than gluing things down. It was based on a mix of two other methods I found online. Basically, I desolder the motor to take out the board, take off the potentiometer (perhaps use polish remover, acetone, to dissolve the glue?) and find the resistance when it is equal between the two terminating pins and the middle pin - assume that this is the middle point - and then insert resistors to simulate that (or can I just insert two identical resistors around this value? Does anyone know this value?) Tuck it away and hope it works...
Or would it be more advisable just to use the method described by SOR?
The motor seems to have survived the abuse of the servo being disassembled on this one I'm working on, at least.
Either way, I know its kind of a long post, thanks for any help!