A Beginner's Guide to Choosing & Using Motors, Servos and More

Summary

This video provides an insightful guide to electrical actuators, explaining their various types such as linear actuators, servos, DC motors, stepper motors, and solenoids. It covers their functions, applications, and key concepts like force, torque, and load. The video offers a clear understanding of how each actuator works, with real-world examples like adjustable desks, remote control planes, and 3D printers. The goal is to help viewers choose the most suitable actuator for their projects, with practical tips on controlling these actuators using microcontrollers and motor drivers. Perfect for anyone interested in adding motion to their creations.

Takeaways

• 😀 Actuators are devices that convert energy into motion, commonly used to add movement to projects. Common types include DC motors, servos, steppers, and solenoids.
• 😀 Linear actuators produce linear (straight-line) motion and are typically powered by a DC motor and gearbox combination. They are simple to operate with voltage control.
• 😀 Force in linear actuators is measured in Newtons or kilogram-force (kgf). For instance, 128 Newtons is approximately 13 kg of force.
• 😀 Linear actuators often feature a worm gear mechanism that prevents movement in the opposite direction when not powered, providing holding force or static load.
• 😀 Servos are actuators that produce precise rotational motion. They are commonly used for controlling angles and are equipped with internal feedback mechanisms for positional accuracy.
• 😀 Torque in servos is rotational force, often measured in kg-cm, and it helps determine the capability of the servo to move or hold weight at a distance from its axis.
• 😀 DC motors are the simplest actuators, producing smooth rotational motion but usually require gearboxes to increase torque for practical applications like RC cars or drones.
• 😀 Stepper motors are unique because they move in discrete steps, allowing precise control over rotation. They are used in applications requiring exact position control, such as 3D printers.
• 😀 A stepper motor doesn't inherently know its position but can be controlled in steps to move forward or backward. It’s often more complex to control than DC motors or servos.
• 😀 Solenoids are simple actuators that move between two positions (on/off) very quickly. They are best used in applications like pinball machines or other tasks requiring fast, limited linear motion.

Q & A

What is an actuator and what does it do?

An actuator is a device that produces motion from energy, typically converting electrical energy into either rotational or linear motion. Examples include DC motors, servos, steppers, and solenoids.

How does a linear actuator work?

A linear actuator contains a DC motor and a gearbox that converts rotational motion into linear motion. It can apply a force, with a typical example being the ability to lift or move objects in a straight line.

What is the difference between Newtons and kilogram-force?

A Newton is a unit of force in the metric system, but it can be hard to visualize. Kilogram-force (kgf) is more intuitive, where 1 kgf equals 9.8 Newtons. This is useful for understanding the force output of actuators.

What is the significance of holding force in a linear actuator?

Holding force refers to the ability of a linear actuator to maintain a position after being extended, even when not powered on. For example, a linear actuator might be able to lift a certain weight, but it can hold it without power because of its holding force.

How does a servo work and where is it commonly used?

A servo is an actuator that produces rotational motion and can be precisely controlled to reach a set angle. It is commonly used in applications where precise position control is needed, such as remote control planes.

What is torque and how is it related to servos?

Torque is a rotational force, often measured in units like kilogram-centimeters (kg cm). For servos, torque determines the force the motor can apply to rotate a load. The longer the arm attached to the servo, the less force is required to produce a certain amount of torque.

Why are DC motors typically used in applications needing constant rotational motion?

DC motors provide smooth, continuous rotational motion without the need for precise positioning. They are perfect for applications like driving propellers or other rotating devices where speed and direction control are needed, but position accuracy is not essential.

How do stepper motors differ from DC motors?

Stepper motors differ by providing precise, incremental steps in rotation, making them ideal for applications that need exact positioning. DC motors provide smooth rotation but do not have positional accuracy like stepper motors.

What is microstepping in stepper motors?

Microstepping allows a stepper motor to take smaller steps, giving it the ability to move in finer increments, such as half-steps or even smaller. This increases precision in control, commonly used in applications like 3D printers.

What are solenoids used for, and how do they operate?

Solenoids are simple actuators that produce linear motion using an electromagnet. They are often used in applications like pinball machines where quick, on-and-off movement is required. They have limited throw and are best used for tasks requiring rapid action between two positions.