When an application requires pure thrust forces, the best type of linear actuator is often a rod-style actuator. Also referred to as thrust actuators and (when a motor is integrated) electric actuators, these electromechanical devices excel at providing axial, or thrust, forces for pushing, pulling, or holding loads. Although their function is straightforward, thrust actuators […]
FAQs + basics
What’s the difference between a servo drive and a motion controller?
Servo systems are made up of four key parts: a motor, a feedback device, a servo drive, and a motion controller. The servo drive and motion controller work together (supported by information from the feedback device) to provide the correct power to the motor so that it executes the intended movement or produces the desired […]
When to consider Kevlar reinforced belts for linear motion applications
Both types of belts commonly used in linear positioning applications — V-belts and synchronous designs — have internal tensile cords that serve as the primary load-carrying component. Or, as one engineer from Gates Mectrol put it, the tensile cords are the “muscle” of the belt. V-belts and synchronous belts are offered with tensile cords of various materials, including polyester, […]
Do IP ratings for ingress protection apply to linear motion components?
When designing, selecting, or assembling a linear system, you may have noticed that some components have an IP rating — IP54 or IP65, for example — while others don’t. Here we explain why that is, and what the IP ratings mean. IP: International Protection (or Ingress Protection) The “IP” acronym stands for “International Protection,” although […]
What are draw-wire sensors and where are they used?
Options abound for tracking or measuring the position of a linear system — from magnetic and optical linear encoders that read changes in magnetism or light, to linear variable differential transformers that operate on the principle of mutual induction, to magnetostrictive sensors that rely on torsional strain induced by magnetic fields. But each of these technologies requires […]
How to use a torque-speed curve to select a servo motor
Servo motors are typically used for dynamic applications, where quick acceleration rates necessitate high torque production. In fact, one of the defining characteristics of a servo system is its ability to precisely control torque across a wide speed range, and the various speeds and torques required during the application’s move profile are a key parameter […]
How to calculate motor drive torque for belt and pulley systems
Belt driven linear systems are common in applications that require long travel and high speed, such as gantry robots and material handling and transport. The motors of choice for these systems are often servo motors, for their ability to accurately control position, speed, and torque. Sizing and selecting the servo motor requires determining both the continuous […]
When should you use microstepping control for stepper motors?
Stepper motor operation is relatively straightforward. The drive sends pulses of current to the motor, and each pulse advances the motor by one step, or fraction of a revolution. The amount of movement per current pulse depends on the design of the stator and rotor. For permanent magnet stepper motors, a full step angle of […]
Why use linear guides and ball screws with ball chains?
One of the differences between radial ball bearings and recirculating ball linear guides has historically been that radial bearings typically use a cage to separate the balls and control their movement, whereas profiled rail guides did not. But in the early 2000’s, manufacturers of profiled rail bearings began introducing versions with ball cages (also referred […]
What are planar errors and how do they affect the accuracy of a linear motion system?
In an ideal world, a linear motion system would exhibit perfectly flat, straight motion and reach the intended position with zero error every time. But even the highest precision linear guides and drives (screws, rack and pinions, belts, linear motors) have some errors due to machining tolerances, handling, mounting, and even the manner in which […]