What goes wrong when inertias aren't right
I've been told that motor and load inertias should match as closely as possible. But now I understand this doesn't apply to servomotors. True? What exactly should the ratio be in this case? ...
What to look for in a servocoupling
Servocouplings are typified by their ability to transmit torque with zero backlash. There are several different coupling designs with this property, so which one should you choose? Here are some basic guidelines to help decide. ...
What's a mechatronics technician?
When Keith Campbell muses about industrial education, his thoughts go back to his uncle Ralph. After graduating first in his high-school class, Ralph got a job as a machinist. He spent a long and satisfying career working in factories with no regrets....
What machine vision is best for your design?
With some help from machine vision systems, automated mechanical systems can align components, read barcodes, guide manipulators, and inspect their own work. Vision and mechanical systems can share the same sensor to measure, find, and orient objects. Without machine vision, engineers must employ additional components such as encoders, proximity sensors, limit switches, and keyways....
The many uses of slip clutches
Most engineers associate slip clutches with their most common application, that of overload protection. But slip clutches also let motors upstream run at a constant rate, to both act as simple drive control and protect motors from excessive wear. ...
How to go green in China: Explain the benefits
Intelligent use of resources, improving the quality of life of workers, and lessening the environmental impact from business operations are key tenets of such initiatives...
Stepmotors: Preventing missed steps
In a perfect motion system, motor turns a certain predetermined amount for every unit of electricity it is given. But if the load on the motor becomes too big, it doesn't matter how much power you try to feed it. Beyond a certain limit — maximum torque rating — motors can no longer turn. Motions become erratic, severely compromising accuracy....
Hot stuff
Turbocharging makes it possible to use smaller engines to get a given amount of power output. This makes fuel combustion more efficient and puts less unburned fuel in the exhaust system...
Hollow-shaft mechanical encoder
The TSE mechanical encoder from CUI Stack Inc., Beaverton, Oreg., features a hollow shaft, eliminating the need to place the encoder directly behind the front panel...
Overcoming vector control challenges
The past few decades have seen a rise in the use of field-oriented control in induction motor applications. One advantage of field-oriented control - or as some call it, vector control - is that it increases efficiency, letting smaller motors replace larger ones without sacrificing torque and speed. Another advantage is that it offers higher, more dynamic performance in the case of speed and torquecontrolled ac drives. ...
Optimizing precision and accuracy
Remember the dartboard analogy? Darts landing near the bull's eye mean accuracy, whereas misfires landing close together, but far from the bull's eye, are more indicative of precision or repeatability. Today's motion systems, of course, usually demand both. Consider these tactics and tools for hitting the mark each and every time....
Guidelines for handling contact in simulations
But simulating contact is not always simple, even with cutting-edge software. Many parameters must be specified to properly simulate contact including the type of contact, stiffness, tolerance, interaction distance, time-step size, and more...
Go for a walk?
At the Robotics Institute on the campus of Carnegie Mellon, grad student Jonathan Hurst is following the age-old engineering principle, "Keep it simple," as he explores two-legged motion systems. His initial prototype, for example, is so simple it only has a single leg and is constrained to two dimensions: up and down, and forward and back...
Managing shock and vibration
Call it what you will — resonance, looseness, vibration, shock load, backlash, imbalance, noise, or strain cycles — none of it is good for machinery and equipment, leading to premature aging, unsafe operating conditions, and errors. Consider the following expert tips and tools for dealing with vibration and its noisy cousins....
Integrating connectivity into systems
Connectivity is the ability to connect to a machine from anywhere in the world and monitor every aspect of the control and motion system. The connection could be via a VPN tunnel over the Internet or Web browser, via a modem, remote view of the machine's visualization terminal, or locally within the factory network to perform the same functions....
