Deciding what motor to use and how to power them can be one of the hardest decisions you make when you start building robots because there are so many choices. The following photograph shows some of the motors that I have used in my projects:
It can save you a lot of money to get used motors, and there are a number of ways that you can acquire them. I have bought numerous used remote-controlled cars and other electronics like old DVD players and removed the motors from them. That is where the two smallest motors shown in the preceding photograph came from; however, if you want more powerful motors, look at removing the motors from power drills. The largest motor in the preceding photograph came from an old Ryobi 12V drill.
When you first start building robots, I would recommend starting with the Arduino car motor. They are very easy to use and are designed to...