The Big Question—What is 3D Printing? - 3D Printing: Build your Own 3D Printer and Print your own 3D Objects - page 11

A Different Type of Motor
Say the word “motor,” and a lot of people's eyes glaze over. Motors are strange,
magical things to some and intimidating and scary things to others. But motors are
important. They get your car from point A to B. They keep your fridge cold (and
everything inside). They make certain the light bulbs have power so you can finish
reading this topic. Motors are everywhere, and they come in all shapes and sizes.
And yes, 3D printers have their own versions of motors.
You don't have to be an electrical engineer to understand the motors found in a
typical 3D printer. I promised I wasn't going to get super-technical on you, so for
now I want you to know these five things about the motors found inside a standard
3D printer:
• They are used for movement.
• They can spin clockwise or counterclockwise.
• They can spin at varying speeds.
• They require electricity.
• They are controlled by a computer.
Most 3D printers have four motors. Remember when I told you that a 3D printer
could print objects that have length, width, and height? One motor each is used to
move the extruder (or the printing surface; more on that in a moment). I'll explain
how this movement occurs later in the topic, but for now all you need to know
is that the motors spin clockwise or counterclockwise to create movement. (The
fourth motor is used by the extruder to feed or push the plastic filament into the
hot end so it can be melted.)
What do these motors look like? Take a look at Figure 1.7 and you'll see a typical
3D printer motor. They don't all look like this one, but most consist of a hard shell
and a shaft that rotates clockwise and counterclockwise.