For many people, the answer to the question ‘what is linear motion?’ is dead simple – motion in a straight line. Running down a track, a linear actuator in motion or anything else that goes straight from point A to point B may seem like one of the most simple tasks, but there’s much complex thought and calculations that can go into linear motion. There are forces at play that can change the direction of the motion.
Motion in a straight line is the most basic form of all motion. The calculations, although they can be made quite complex, can be done using only one dimension. If you were to send something in a single direction in the vacuum of space, it will travel in a straight line until another force acts upon it and changes the direction or speed. This is Newton’s first law about ‘net force’. When something has no resistance from any other object, it will move at a constant speed infinitely. Of course, this rarely happens, because here on Earth we have forces like gravity and friction that are constantly pushing and pulling on any object that moves.
The Forces Affecting Linear Motion
One of the many reasons you can still stand here is gravity is constantly pulling on you, keeping you as close to its core as it can. Any time you throw something, the force of gravity pulls it downward and you get that classic downward curve, like when you throw a ball. When a 12V linear actuator is used to create linear motion, the motor is the force that is used to overcome gravity. Of course, when there is nothing on the actuator, gravity is not a hard force to overcome. You can temporarily overcome gravity yourself if you jump. Once you place something on top of a 12V linear actuator, you are making it harder for the force of gravity to be resisted. As a result, the motor must work harder and the velocity, or speed, of the actuator slows down.
Thinking about friction, there are many things that can exert a friction force on a linear actuator. Even something as simple as the wind can have an effect, but most of the time unless the wind is from an airplane engine, it won’t do much. Other friction for a 12v linear actuator can include the lead screw and the nut system. These systems have been created to give the least amount of friction possible, but the nature of the systems cannot negate friction entirely. As such, it just means it’s a force to be overcome.
Way out in the vacuum of space, an object can constantly move in a single direction endlessly, until it hits something or gets drawn in by gravity. These forces of friction and gravity are much more common on Earth, because we can’t escape them. Instead, we and our technologies must overcome them. If you once asked yourself, ‘what is linear motion?’ and thought there was a simple answer – there is, but the various forces that are acting on linear motion can make the process much more complex than it seems at first.