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 i