Drill Motor Speed Controller Bracket

Harbor freight drill motors are commonly used for combat robot projects due to the cheap price tag. 20$ for a motor and 18V Ni-Cd, hell yeah! The problem I had was finding a motor controller for under 100$ per motor. I managed to scrape together a 30A setup which costs about $15 per motor, plus an additional $10 for an arduino which can support up to 4 motors. The motor controller has a 0-5V analog input, then use the dual relay board to control the direction you want the motor to spin. I have included a wiring diagram and links to two board used. I originaly purchased these boards on ebay, so if you buy the ones linked it with be ~28$.

Demo video: https://youtu.be/5luJtLUHcbo

Cordless drill - http://tinyurl.com/hc5fwsq
This is the same cordless drill that harbor freight sells for 20$.

Motor Controller - http://tinyurl.com/MotorController40
One note is this controller linked does not have master and slave mode. You would have to cut off the potentiometer and run the yellow w