Heli's motor take up very high current. So, a motor driver that supports less than 4 or 5 Amps was out of the question. We did not have FET's to make a H-Bridge, so we hacked upon the radio box of the heli and connected a cable to the FET bridge already there. We also [...]

A Hokuyo Range sensor costs you $2000 and a cheapo SHARP IR sensor with a servo is $20, max!.  The difference between them is probably only that the range sensor is more mechanically stable and hence faster. The range sensor that we hacked is actually an IR sensor pasted over a servo. And a servo [...]