The advantage of steppers over DC motors is that you can achieve much higher precision and control over the movement. Servos though, are usually limited to a 0-180 degree range, while a stepper motor can rotate continuously, similar to a regular DC motor. For practical purposes, a stepper motor is a bit like a servo: you can tell it to move to a pre-defined position and can count on getting fairly consistent results with multiple repetitions.
One thing that you cannot tell from the video is how quiet these little steppers run: StepperBot is very stealthy! Eventually, small errors add up over time and the bot falls off the table, but it typically runs for 10-15 minutes, before that: good enough for me! What is so special about steppersĪ stepper motor can move in accurate, fixed angle increments known as steps. The motors are running at approximately 8 volts DC and 15 RPM in this example.
Movement is controlled only by the number of pre-defined steps in each direction hard-coded in the sketch. The robot has no sensors for positioning, orientation, or a way to detect the edges of the table. Turning exactly at the right time and by the right angle is critical avoid falling off and crashing on the floor in an embarrassing pile of messy wires. First, lets see the little steppers in action! Our main character, StepperBot, is “instructed” to move in a square path on my coffee table, making 90 degree turns at the corners.
