Whether in the classic church setting or in modern rock music: the organ is the queen among musical instruments. It remains unequaled in its variety of sounds. While the sound is generated electronically on modern organs, air still sets the tone on the classic instruments. Instead of relying on human muscle, however, the arduous work […]
FAQ: What is microstepping?
Microstepping is driving a stepper motor at less the one full step per movement. Under usual operating conditions, a stepper motor operates by turning one full step with every pulse of current. Microstepping allows a motor to make far finer steps. This done by having the controller and drive send the proper kinds of current […]
FAQ: What drive conditions make stepper motors run poorly?
When selecting a drive for a stepper motor, remember that certain drive setups and may cause the stepper motor to run poorly. These include improperly sized motors, incorrect drive types and incompatible wiring schemes. Having a correctly sized stepper drive is vital. If this is not done, then there is the risk that the motor […]
FAQ: How do stepper drives work with stepper controls based on PLCs?
Programmable logic controllers, or PLCs, are computers that control automation and motion systems. They are real-time computers in which inputs must create outputs in limited time. They usually store programs that perform control algorithms in non-volatile memory or battery-backed memory. Using a PLC with a stepper drive allows control mechanisms to change using software control, […]
FAQ: How could drives soon make switched-reluctance motors more common?
One the main drawbacks to switched-reluctance motors come from their control and drive electronics. They must be accurate and responsive to monitor continually various aspects of the motor for it to run effectively. However, as technology improves switched-reluctance motors may become more common with the rise of improved drives and controllers. As mentioned in FAQ: […]
FAQ: Why are switched-reluctance motors (SRMs) so difficult to control?
Switched-reluctance motors have many advantages, including low cost and low energy use. However, their main drawback is they are difficult to control. This is for a variety of reasons. Namely, they need highly accurate position tracking, the inductance in the motor changes with the degree of alignment of their poles; they require unipolar drives, and […]
FAQ: How to choose a safety factor so a motor design lasts?
Engineers determining what stepper motor and drive to use should make sure to include a safety factor. This is because there could be some unanticipated loads or operating conditions that may affect the operation of the system. On the other hand, too large a safety factor has its drawbacks as well. These include wasted power […]
FAQ: What features need to be compatible for a stepper drive to run a given stepper motor?
When selecting a stepper drive, certain features must be compatible with the motor and the drive for the system to function. These include the current output of the drive, whether it is for unipolar or bipolar stepper motors, its voltage output and its wattage or power rating. All of these factors matter for their own […]
FAQ: How do AC stepper drives offer better torque-speed performance than DC?
When selecting stepper drives, AC and DC options are both readily available. However, AC drives can often provide better torque-speed performance than DC drives. There are a couple reasons for this. More current means more torque When driving stepper motors, the general rule of thumb tends to be the more current a drive can provide to […]
FAQ: How to size stepper motor power supplies?
Stepper motors are sensitive to the performance of their power supplies. Stepper motor power supplies can affect: Rate of motor heating — read FAQ: Aren’t heat and noise common stepper motor problems? for more on this Acceleration — read FAQ: What are the requirements for a stepper acceleration? Torque — read FAQ: What kind of torque […]
FAQ: What are PID gains and feed-forward gains?
Gain is the ratio of output to input—a measure of the amplification of the input signal. A common example is the volume button on a stereo. This button controls the ratio of the input signal (received from the radio station) to the output signal (how loud the sound is from your speakers). When the volume is […]
FAQ: Why would shaft inertia cause extra steps, and how to prevent this problem?
Inertia affects how stepper motors turn. For example, extra steps and missed steps can happen when a system has inertia mismatch — as detailed in FAQ: How do stepper motors handle inertia mismatch? Another source of missed steps is the motor inertia itself. The motor-shaft inertia is one culprit. This shaft rotates and has a […]
FAQ: What is a pulse rectifier and what kinds are there?
Variable frequency drives are made up of three primary sections: a rectifier, which converts the supplied AC voltage to DC; a DC bus, which stores the DC voltage; and an inverter, which converts the DC power back to AC at the voltage and frequency required by the motor. The most common, and simplest, rectifier designs use […]
PI’s award-winning fast multichannel photonics alignment engine
The FMPA Fast Multichannel Photonics Alignment Engine is an advanced alignment system based on a highly specialized digital motion controller with embedded advanced alignment and tracking functionality and a hybrid precision scanning and tracking mechanism combining the advantages of piezoelectric on servo-motorized drives. More after the jump. From motion control and nanopositioning solutions expert PI […]
FAQ: How to set a stepper motor’s current limit and why is it important?
Edited by Zak Khan || Stepper-motor current limiting serves a few functions. Stepper-motor overcurrent can cause overheating as detailed in FAQ: Aren’t heat and noise common stepper motor problems? At its most extreme, overcurrent can cause rotor demagnetization. Recall that current effects acceleration — as in FAQ: What are the requirements for stepper motor acceleration? So […]
Short axial length, high-torque brushless motors from Koford
Koford Engineering offers a new line of 10-pole 5.07-in. (129 mm) brushless high performance motors with continuous stall torque up to 398 oz-in. with heat sink, and peak motor efficiency of 94%. The motor features low cogging for a slotted motor and a sinusoidal back emf for low torque ripple when used with sine drives. […]
New ways of controlling indexing tables for precision motion
There are key differences between fixed-position indexing tables and closed-loop position indexing tables. Here we review them and how to control for maximum accuracy. By Ken Pfahl, Sales Manager | Motion Index Drives Indexing tables come in an array of versions with different speed and dwell settings to satisfy tasks in machine-tool handling, stamping, medical-device […]
FAQ: What are the requirements for stepper motor acceleration?
Edited by Zak Khan || Engineers should give thought to acceleration when starting a stepper motor. Simply programming the controller to advance the motor some steps isn’t sufficient for reliable operation. Programming must also account for stepper-motor construction and operation. As mentioned in FAQ: How do I prevent stepper motor stalls? and FAQ: How do stepper […]
FAQ: What kind of torque can I get out of a stepper motor versus other options?
Stepper-motor output torque depends on a few things — including the stepper-motor type; how many poles it has; how fast it runs; and the type of drive supplying electrical power to the motor. For the latter, read FAQ: What is a stepper drive and how do they work? for more information. More specifically, a […]
FAQ: How do proprietary and open-source PC control software programs compare?
The central issue with anything that is programmable is the programming itself. Regardless of whether the system is open source or proprietary, the key to successful control applications is to correctly program the design intent. Capturing the full intent at the start of a project is impossible, especially if the project has not been done […]
FAQ: Why do so many PC controls integrate HMIs?
By Steve Meyer || Previous generations of control relied on Cathode Ray Tubes (CRTs) for information displays as part of programming terminals. Those unfamiliar with CRTs should read the Wikipedia articles and check Google Images for representations of how the CRT works. It is an interesting part of the history of control. CRTs use high-voltage power supplies […]
FAQ: How do I pick between automation technologies that use PC controllers?
Today’s state-of-the-art PC-based controls deliver performance that exceeds most industrial machine-control requirements. Processor power and memory continue to expand — following Moore’s Law and doubling in capability every couple years. What’s more, cost per processor continually declines as performance increases. Whenever control manufacturers update their electronics, it makes more power available to end users. Here’s […]
FAQ: What is tag naming and the point of defining data types with PAC programming?
By Steve Meyer || Tag naming starts with naming the I/O in a control system. The names might only serve as a bookkeeping convenience for documenting in ladder programs, but in the complex environment of today’s PLC and PAC platforms, tag names are more significant. Tag names can serve as a referent for I/O points in totally […]
FAQ: How to unify distributed I/O with PACs when building new?
By Steve Meyer || A major hardware cost in control systems is that for inputs and outputs. Devising the most suitable arrangement of I/O takes creation of an I/O map. Then grouping I/Os by location helps engineers identify packaging needed to deploy hardware correctly. One caveat: Unless one is using new breeds of design software, mapping and […]
Top 6 motion control stories of 2016
Motion control, a wide-ranging field made up of scores of components and subsystems, garners a lot of attention. We thought it would be fun to take a look back over the past year to see what readers were interested in the most. So here are the top 6 stories from MotionControlTips.com for 2016. 1. What’s […]