I had an idea using a continuous rotation servo mod as a cheap DC motor driver with pwm input. 

It works but not very well, maybe for an rc hotwheel but not enough power to fly and most small servos don't really like going about 5v.. so 2s 7.2v would probably not help.

The mod also requires some expensive tiny high precision resistors, without them the noise on the signal becomes another problem..

This should be on my other project page but whatever they are all the same to me...

Micro + NRF PCB

1. pwm out on 5/6 originally meant for just wireless synced RGB (Coming soon...)
2. v2 added a tip120 for an extra Lamp output with rgb
3. v3 became the controller board.
4. v4 (mocked up with v2) + l293D breakout board will become the main control board RX

• 2 dc output at 600ma each >16v input range..
• 2 servo output
• a couple free digitals/softservos
• ordered the pcb so testing in a week or 2...

if it works I've already thought about linking multiple l293D ic's in to a single I2c controled micro with 4 1.2A motor channels...

But the scorpion need to be brushless i think...