What is a Linear Actuator?
What is a Linear Actuator?
Getting started with mechanics can be fun and rewarding, but whether you’re building simple bike mechanisms, putting together robotics, or even getting started with building moving parts in cosplay, there’s a lot to learn. For example, the linear actuator.
If you’re not accustomed to working with parts, you probably have a lot of questions like what is it, how does it work, and what do you do with it.
While most of us who don’t work with robotics and moving parts have never heard of an actuator, the simple linear actuator is found in a surprisingly large numbers of things. For example, in printers, braking cylinders, wheelchair mechanisms, your smartphone, robotic arms, and much more.
So, what is a linear actuator? Let’s get started.
What is a Linear Actuator
An actuator is a type of motor. You probably know that a traditional motor creates circular motion, typically using a series of gears and belts. A linear actuator creates movement in a straight line, typically using a cylindrical valve that can slide in and out to create motion and sometimes energy.
You can typically see linear actuators in a variety of different applications such as in optical drives and printers, but the mode of actuation, or movement, can vary a great deal.
- Mechanical – Uses a simple mechanical process such as a wedge, wheel and axe, or screw to turn or slide
- Hydraulic – Uses hydraulic pressure (liquid) to actuate
- Pneumatic – Uses pneumatic pressure (gas or air) to actuate
- Piezoelectric – Uses piezoelectricity to move. Not typically available on the market
- Electric/Electro-mechanical – Uses electricity to move a mechanical element to actuate the motor.
What About Feedback Actuators?
Feedback actuators are linear actuators with positioning control, which allows them to offer feedback regarding motion. These actuators feature potentiometers to read the position of the screw or spindle in the feedback actuator as it moves, allowing you to improve the control of the actuator.
When combined with a control system, a feedback actuator can be used to create smooth and steady movement, because you can set start and endpoints for the mechanical part of the device, so that the movement starts and ends where desired, rather than going all the way up and all the way down. This makes them much more valuable for projects that need control and smooth motion. They’re also ideal for projects where you need to know what is happening and when, because you can track movements as well as program them.
A feedback linear actuator is also known as actuators with potentiometer or potentiometer actuators.
Choosing an Actuator
Choosing an electric actuator for your needs should depend on your project, however, most choose electric actuators. A simple 12v feedback actuator gives you the benefits of linear actuated motion with more control, which is beneficial for delicate projects as well as those which you need to track or control to create specific ranges of motion. This makes it most ideal for beginners who want a multi-purpose tool they can use for a variety of applications.
However, you can consider the following when choosing an actuator.
- Mechanical – Cheap and no power source required. Every movement is identical. However, automatic operation is not possible.
- Electric – Cheap and self-contained. Can be battery powered and automated. Available with feedback.
- Piezoelectric – Very small, fast movements. Typically electric allowing feedback and automation. However, they require high voltages and are very expensive.
- Hydraulic – Very high force enabling a lot of movement, but requires feedback and an external pump. These actuators are too strong for most at-home projects.
- Pneumatic – Strong, simple, and fast, but not precise enough for robotics.
Now that you know what a linear actuator is and how it works, hopefully you can pick a great one for your project. Good luck!