DC Motors vs. Servo Motors

Motors vs. Servos

So wait, there's more than just motors?

​Rotates 360° very quickly. Best for movement. Not good for precision.

DC Motor

Unless otherwise specified, does not rotate 360°. Slow. Best for precision controlling of parts.

Servo Motor

Specialty motor that is used for highly precise movements that can be repeated over and over. We will not use stepper motors in this class.

Stepper Motor

DC motors take electricity and convert that into magnetic energy. This magnetic energy turns a shaft in the middle of the motor.

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​DC Motors

• Inaccurate

• Weak without a gear system

Cons

• Speed

• Good for continuous rotation

• Reduce voltage, reduce speed

• Can run for a long time without damage

Pros

DC Motor Pros and Cons

Servos have a DC motor, but also a device called a position potentiometer. This reads exactly where the shaft has turned, and sends the data back to the computer.

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Servo Motors

• Most only rotate 180°

• Can only be turned electrically (NO PLAYING WITH THEM)

Cons

• Precision

• Higher torque (stronger)

• Great for highly accurate movements (grabbers!)

Pros

Servo Motors Pros and Cons

So Which is better?

Neither. They're both needed to make robots. Each has its own use.

Multiple Choice

You're making a robot that needs to get up a hill as fast as possible. Which motor should you use?

• DC Motor

• Servo Motor

• Neither

Multiple Choice

You're making a robot that has to extend an arm, grab something, flip it 180°, and put it back down. Which motors would you want?

• DC Motors

• Servo Motors

• Neither

Drag and Drop

A pro of a servo motor is ​

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. A con is ​

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Drag these tiles and drop them in the correct blank above

precision

lack of rotation

inaccuracy

wide range of motion

continuous rotation

speed