With each discrete step that a stepper motor makes, the inertia of the system causes the motor to slightly overshoot (or undershoot) the intended step angle. The motor then oscillates, or “rings,” until it finally settles at the commanded position. If the frequency of these step-by-step oscillations is at or near the motor’s natural frequency, […]
When is the application of overvoltage safe (and common) for stepper motors?
For most types of motors, operating with a supply voltage that is higher than the rated voltage — referred to as overvoltage — can cause an increase in current, and heat, high enough to damage the coils and other motor components. But in some cases, a stepper motor can be operated at a voltage higher than rated […]
Which types of DC motors can be used as servo motors? (And a refresher on DC motor technologies)
Servo motors are used in applications where precise control of position, speed, or torque is required. But many different types of motors can be considered servo motors — the defining feature of a servo motor is that it incorporates or reads feedback in a closed-loop system. In fact, although many servo applications use synchronous AC motors, […]
The top 10 motion control articles of 2021
We cover a wide variety of topics here at motioncontroltips.com — from Industrial Ethernet and networking to springs and shock absorbers. So, naturally, our most-read articles typically span a wide range of subjects. But 2021 was a bit different, with all but one article being related to motors, and more than half of the articles […]
What determines worm gear efficiency, and is it really that low?
Worm gears are often used for their ability to provide very high reduction ratios (and high torque multiplication) in a compact, single-stage design. But traditional thinking says that these benefits come at the expense of efficiency. Here, we’ll look at the factors that determine worm gear efficiency and how to get the benefits they provide […]
What is cyclic synchronous control (position, velocity, and torque)?
Cyclic synchronous control modes — cyclic synchronous position, cyclic synchronous velocity, and cyclic synchronous torque — are standardized operation modes of drives, defined in the CiA 402 profile specification, CANopen device profile for drives and motion control and included in the IEC 61800-7 standard, Adjustable speed electrical power drive systems — Part 7: Generic interface and use of […]
Why is RMS current important in stepper motor applications?
Most precision stepper motor applications — especially those in automation and motion control — use a control method referred to as microstepping, which creates a sinusoidal (or nearly sinusoidal) current waveform, rather than the square wave of current produced with typical full-step control. The current rating of a stepper motor depends on the amount of […]
What is the CANopen over EtherCAT (CoE) protocol?
The CANopen over EtherCAT (CoE) protocol allows devices equipped with CANopen to be used on EtherCAT-based Industrial Ethernet networks. CANopen: Simple and low-cost CANopen is a communication protocol based on the CAN (Controller Area Network) physical communication standard. In the OSI communication model, CAN specifies the physical and data link layers, while CANopen addresses the […]
How do wave springs eliminate problems associated with traditional coil springs?
Coil springs and wave springs are both types of compression springs, meaning the spring’s force increases as its axial length decreases (as the spring is compressed). But coil springs and wave springs react differently to applied loads, especially in terms of how stresses are created in the material, which in turn, affects their working load […]
What are interferometric laser encoders and where are they used?
Optical encoders such as glass scales are often used for linear position measurements that require micron-level resolution. But applications in industries such as semiconductor and aerospace — especially those that involve optics — require measuring capabilities in the nanometer and even picometer ranges, beyond the resolution of most scale-based optical encoders. For these applications, direct, non-contact […]
