This is my first time posting on the Arduino forums. I am working with a group on a capstone project to turn an electric lawn mower into a lawn mowing robot. The base of our project is the Greenworks 25272 mower, which you can see here: http://www.sears.com/shc/s/p_10153_12605_07189543000P?adcell=P1_mowerfinder . My job is to figure out how to move the mower straight and make turns.
The mower comes with a setup for self-propelling which amounts to pulling a lever to control a gearbox on the back axle. Our plan at the moment is to remove the rear axle and gearbox and instead attack a motor to each wheel, allowing us to move straight or turn. So far we've purchased one DC motor (Ampflow E30-400: http://www.ampflow.com/three_inch_high_performance_motors.htm ) and an Arduino motor shield (http://arduino.cc/en/Main/ArduinoMotorShieldR3 ). According to the information on the motor shield we can drive 2 motors, but our motors require a much larger voltage than the recommended supply.
My questions at the moment are: 1. Should we be using DC motors? We also have the option of using stepper motors, which I understand are more precise because we can control the rotations. 2. Do we need to purchase a controllable power supply, or will a battery work fine? If anyone has any experience with projects like this please feel free to offer any advice you might have. At the moment I am trying to figure out exactly what parts we need to get the mower moving. Thank you!