Linear Actuators – Keeping Industry in Line
It’s easy to conceptualize a linear actuator being put to use in an automotive, automation or assembly application. Automotive linear actuators are found in car jacks and retractable truck bed covers. Other actuator varieties are used to create and control the motion of robotic assembly equipment. Still others are used to push open automatic doors. These applications seem like normal, sort of garden-variety industrial processes, which they are. But linear actuators can also be put to use in some comparatively exotic applications.
Take the film industry, for example. Linear actuators are valuable in the film industry for the same reasons that they are valuable to other industries; they generate carefully controlled, fluid linear motion. Humans are limited in terms of their ability to move fluidly. Take a look at your hand. Hold it out, parallel to the ground, right in front of your eyes, and see how still you can hold it. Now, try moving your hand back and forth in a perfectly straight line, without any shaking. Imagine trying that with five, ten or even a hundred pounds of camera weighing you down!
Even the most disciplined human body isn’t capable of the kind of rigid motion control that is required to keep a camera perfectly steady. Linear actuators are among a short list of devices that make possible the kind of rock-solid camera movement required in many films. Especially in high-budget movies, cameras are often mounted on linear actuators, which in this context are sometimes called slides, and which allow the camera to be moved back and forth as it follows the action. Their motion can be powered by pneumatics, hydraulics, an electric motor or a combination of one or more of those power sources.
While smooth linear motion may not be exciting on its own, when you consider how many different ways it is put to use throughout industry, it can be easier to appreciate.