The motors as actuator device is very and very important to understand. There are many things need to be calculated… velocity, torque, motor voltage and motor current. There is nice post from societyofrobotics about DC Motors. The most important one is about torque… I’ve so confused about choosing DC motors for my robot and now I am figuring that DC motors must have enough torque for running smoothly…
Here the nice article about DC motors:
From the start, DC motors seem quite simple. Apply a voltage to both terminals, and weeeeeeee it spins. But what if you want to control which direction the motor spins? Correct, you reverse the wires. Now what if you want the motor to spin at half that speed? You would use less voltage. But how would you get a robot to do those things autonomously? How would you know what voltage a motor should get? Why not 50V instead of 12V? What about motor overheating? Operating motors can be much more complicated than you think.
You probably know that DC motors are non-polarized – meaning that you can reverse voltage without any bad things happening. Typical DC motors are rated from about 6V-12V. The larger ones are often 24V or more. But for the purposes of a robot, you probably will stay in the 6V-12V range. So why do motors operate at different voltages? As we all know (or should), voltage is directly related to motor torque. More voltage, higher the torque. But don