Featured Permanent Magnet Stepper Motors

  • Frame Size: 15mm
  • Holding Torque: 0.4-0.6 oz-in.
  • Current: 0.04-0.5A
  • Frame Size: 20mm
  • Holding Torque: 0.7-1.1 oz-in.
  • Current: 0.2-0.5A
  • Frame Size: 25mm
  • Holding Torque: 1.5-2.4 oz-in.
  • Current: 0.2-0.7A
  • Frame Size: 25mm
  • Holding Torque: 1.8-1.9 oz-in.
  • Current: 0.2-0.7A
  • Frame Size: 35mm
  • Holding Torque: 4.9-7.6 oz-in.
  • Current: 0.4-0.5A
  • Frame Size: 35mm
  • Holding Torque: 4.6 oz-in.
  • Current: 0.5A
  • Frame Size: 42mm
  • Holding Torque: 6.9-11.1 oz-in.
  • Current: 0.1-0.6A
  • Frame Size: 49mm
  • Holding Torque: 23.6 oz-in.
  • Current: 0.9A
  • Frame Size: 57mm
  • Holding Torque: 16.7 oz-in.
  • Current: 0.6A

Helpful Information
Along with the stepper motor, Anaheim Automation carries a comprehensive line of drivers and controllers, power supplies, gear motors, gearboxes, stepper motor linear actuators and integrated stepper motor/driver packages. Additionally, Anaheim Automation offers encoders, brakes, HMI couplings, cables and connectors, linear guides and X-Y tables. If the stepper motor is not ideal for your application, you might consider brushless DC, brush DC, servo, or AC motors, and their compatible drivers/controllers.

• Cost-effective* • Simple designs • High reliability • Brushless construction • Maintenance-free • If windings are energized at standstill, the motor has full torque • No feedback mechanisms required • High acceleration and power rate • A wide range of rotational speeds can be attained as the speed is proportional to the frequency of the input pulses • Known limit to the dynamic position error *Stepper motor products vary in cost based on the criteria for each application. Some criteria include options of 0.9°, 1.8°, 3.6° and 4.5° step angles, torque ranging from 1 to 5,700 oz-in, and NEMA frame sizes of 08 to 42. Additional attachments such as cables and encoders can be purchased separately for an additional cost. With our friendly customer service and professional application assistance, Anaheim Automation often surpasses customer expectations for fulfilling specific stepper motor and driver requirements, as well as other motion control needs.

Axis Wind Tunnel Project
One of Anaheim Automation Inc.s customers provides services and products for the automobile industry, such as process automation, prototyping, engine test standards, and gauging equipment. At one point, our customer encountered a problem; popular cars were being redesigned, and they needed computer control of a stepper motor for their project. They had tried several other motion control manufacturers before deciding to have Anaheim Automation help them with their project. The project dealt with the cooling of an engine in a strange area. Anaheim Automations assignment was to construct a prototype that would scoop air from beneath the car and redirect maximum air flow to this area. It was almost impossible to predict an accurate shape that would allow precise airflow, due to the fact that in order to fit in the available space, the duct had to be in an extremely complex configuration. The solution to this problem involved making a flexible duct that, by moving its parts, allowed it to be reshaped. The duct would be mounted in a wind tunnel, and installed in the prototype of the car. Next, engineers experimented with the ducts shape until they discovered what shape allowed for the best air flow. This shape became the basic model to construct in the overall prototype. Anaheim Automation needed to shape the duct without diverting from the project goal, and therefore needed 15 axes of motion and one easy-to-use controller. To meet this necessity, Anaheim Automation assembled five triple-axis stepper motor drivers, programmable indexers, an interface, and the necessary power supply into a compact package, along with 15 compatible stepper motor models. When the computer was turned on, the program came up, so the system didnt require any knowledge of the computer operation. In addition, it reduced operation to simply answering three questions (prompting the user). The user could change the speed at any time; however, the operator did not need to know anything about base speed, acceleration, or deceleration, because the parameters for optimal motor speed was preloaded with the system program. While operating, the program prompted the operator with, What axis, how many steps, and which direction? The user only needed to press the F1 function key to produce the desired motion for the stepper motor to move. With the experiment in full swing, engineers were able to manipulate the air duct in order to achieve maximum air flow underneath the vehicle. The required motion was easily produced at the press of a button, and the positions could be easily repeated. Ultimately, our customers engineering staff was able to determine the exact shape of the duct that provided the car with maximum air flow. Simple, low-cost, and extremely efficient stepper motor products, and drivers provided the solution the customer required.

Easy Automation for Custom Machinery Manufacturers
Automation and Material Handling specialists create products for a broad range of businesses, including automotive, pharmaceutical, packaging and electronics companies. Anaheim Automation, Inc. has been a supplier to these companies for over 40 years. When it comes to automating equipment, machinery and processes, some methods are efficient, while others are not. Anaheim Automation has an outstanding record for choosing sensible methods and cost-effective designs, but when we recommend multi-axis stepper motor Driver Packs and boards for moderately straightforward machines, they maximize their cost effectiveness even further. For single-axis applications that are redundant and require accurate positioning, the economical DPD72451 Preset Indexer Driver Pack is ideal, and has been a long-time favorite. Each compact stepper motor Driver Pack contains a preset indexer, a bi-level stepper motor driver, a power supply, and a cooling fan. The preset indexer has such abilities as Home, Hard and Soft Limit inputs, two Homing modes, Jog/Run, Fast Jog, and switch selectable Base Speed, Maximum Seed, and Acceleration/Deceleration. The DPF72452 Stepper Motor Driver Pack offers the same performance for two axes. It is a larger unit with twice the capacity. The companion Quad Board is consists of four banks of digital pots mounted on a PC board, along with the supplementary circuitry. According to what the user desires, the board has the capacity to dial in up to four different move lengths. Anaheim Automation simplifies installation by offering the Quad Board connected to and mounted on the stepper motor Driver Pack. A classic example of this inventive production is a machine that rivets stiffeners on the edge of up to 800 circuit boards per hour. In this practical application, wherein stepper motor products are used, Anaheim Automation, Inc. helped a machinery manufacturer build equipment for a telephone company. This particular machine had the requirement of automatically installing stiffeners along the edge of circuit boards. A stiffener is added from a magazine, to each board that is positioned on a linear table. The stepper motor, operated by the Driver Pack, positions a table so the rivets can be inserted through the stiffener and the board in three different areas: a distance of 1-1/2 in. from the first hole, 4-1/2 in. to the second hole, and 4-1/2 in. to the third hole, and return to home. The Quad Board settings were used in order to keep two additional settings available to handle any prospective complex arrangements. Despite how simple the machine was, it was also capable of extraordinary tasks; one example being its ability to turn out 800 boards in one hour. Anaheim Automation used the same idea for other, very different machines. In the case of a pharmaceutical company; they used a flutter valve maker. For this machine, a roll of vinyl was advanced to a dimension, heat sealed, and cut along the seal. Each of the two rolls provide two valve sizes. In this case, the stepper motor controlled a drive-roller against a pinch roller, and the Quad Board settings controlled the length of the material. This left two settings for further expansion. Just like our other machines, efficiency coincides with simplicity. In this example, we can turn out 15 flutter valves a minute. This approach not only provided the benefits of simple and efficient productivity, but it only required a simple interface with a machines PLC. There was no need for high level software; therefore Anaheim Automation was able to maintain lower costs, and simplify service considerations.

Industries that Use Stepper Motor in Their Design
Stepper motor products are versatile motion control components that can be applied to several different industries, from entertainment and film, to the business world, to science and medicine. Aircraft: A stepper motor is frequently used in aircraft instruments, scanning equipment, and sensing devices, such as antennas. Automotive: SUVs and RVs, as well as some high-end automobiles, use the stepper motor to receive telecommunication signals. A stepper motor is also used for cruise control, automated dashboards gauges and electronic window equipment, as well as in automobile factories on their production lines. Cameras - Filming and Projection: Not only does the stepper motor operate filming cameras and projectors, in the entertainment industry, but automatic digital cameras and mobile phone camera modules utilize tiny stepper motor for focusing and zooming functions as well. The security industry also uses a stepper motor for zooming, tilting and scanning operations in surveillance and security cameras. Entertainment and Gaming: Slot machines, lottery machines, raffles, card shufflers, and wheel spinners can all be operated by cost-effective and reliable stepper motor. You can also find the stepper motor in stage productions to control curtains and lighting functions, for plays and concerts, as well as seminars and rallies. Laboratory and Factory Improvements and Upgrades: A stepper motor is employed to perform tedious movements pertaining to mixing chemicals in laboratories, and operating equipment for controlled environmental testing. The stepper motor is used in retrofit kits (stepper motor, drivers, controllers and power supplies) for CNC machine control, factory automation and assembly processes. The stepper motor can also be found in scientific study, used to position observatory telescopes, and in many different types of scientific equipment, i.e. spectrographs, analyzers, and diagnostic machines. Medical: The stepper motor provides a wide variety of functions for the medical and dental world. The stepper motor is used within medical scanners, multi-axis stepper motor microscopic or nanoscopic motion control of automated devices, auto-injectors, samplers, dispensing pumps, respirators, blood analysis machinery and chromatographs. In the dental industry, a stepper motor operates fluid pumps, and are often found inside digital dental photography equipment. Office Equipment: PC based scanning equipment, optical disk drive head driving mechanisms, bar-code printers, label and box printers, scanners, and data storage drives all utilize the stepper motor for their motion control operation.

Musical Motors, Stepper Motor and Their Virtuoso Performance
Anaheim Automations tremendous versatility of control systems is evident in their new program titled, Musical Motors. They have utilized stepper motor, stepper drivers, and stepper controllers to operate at speeds that coincide with musical notes and pitches to produce a number of different tunes. Each tune is performed by simply running the program that converts each music note into a certain step-per-second. All of the different stepper motor are programmed to produce an appropriate pitch based on how many steps-per-second they run, and for how long. Typically played at a trade show, the program provides the element of surprise; most people do not expect to hear music that is being played by stepper motor!

Packaging House Speeds Bottle Handling
Employees were hired at a local packaging plant, for the sole purpose of making sure bottles were packaged with their labels facing outward in their packages. They were employed to manually adjust the positioning of the bottles and send them to the blister pack machine. Anaheim Automation helped expedite that process using stepper motor and drivers. With the new automated design, bottles were sensed with a photo-electric sensor that stops the belt and notifies the pulse generator in an Anaheim Automation Driver Pack. The stepper motor Driver Pack controls a stepper motor, which rotates the bottle by turning a rubber drive wheel. An orientation indicator is placed on the bottle that, when sensed, prompts the pulse generator and activates a discharge solenoid, which then places the bottle into the awaiting package. The packaged bottle then allows the photo sensor to trigger the next bottle to come into position to repeat the process. Implementing this process using a stepper motor Driver Pack resulted in quicker packaging with viewable bottles, at a considerably lower cost! Both the customer and its intended end-users were quite pleased with this development.

Popular Driver Pack Comes with Preset Indexer
The new DPD72451 Driver Pack is an individual preset indexer module, complete with Control Link (Indexer), BLD75 bi-level driver, and matched power supply. In order to handle all aspects of positioning on a single axis, it is ready to connect between an input device such as a thumbwheel switch counter, with a stepper motor. The preset indexer board was originally built around the capabilities of a single-chip indexer. The chip is derived from the SMC 20BC, a programmable stepper motor controller chip. It features hard and soft limit outputs, three homing modules, jog/run, fast jog, and programmable base speed, maximum speed, and acceleration/deceleration. The Driver Pack therefore provides extended capabilities that make it applicable to a broad range of functions, the most popular being cut-to-length. The necessary buffering and other circuitry required to support the chip is also included. However because the units are mounted separately in most installations, a thumbwheel switch is not included on the indexer. Anaheim Automation offers numerous different input devices for use with the DPD72451, including three-, four-, five-, and six-decade thumbwheel switch encounters; two-, four-, and six-decade rotary switches; and two-, four-, and six-quad rotary switches. The high-performance bi-level driver BLD75 operates four-, six- or eight-lead stepper motors. Due to its characteristic of being a bi-level driver, it provides high torque (power) output and high start-stop speed. The power supply in the DPD72451 is fan-cooled and matched to the requirements of the PCL451 and the BLD75 bi-level driver. Together, the indexer, bi-level driver, and matched power supply provide a complete, concise package with exceptional price and performance for a myriad of different applications. When two axes are required, two PCL451s can be housed in a larger Driver Pack, along with dual bi-level drivers and the appropriate power supply.

Stepper Motor
The stepper Motor is currently used all around the world for many types of applications. These motors provide as constant power devices. At low rpms a high torque can be achieved the same cannot be said when the speed is increased. A high torque cannot be achieved at higher rpms. These motors are great for positioning objects, such as conveyor belts, assembly lines, lathes, laser cutting, grinding and drilling machines, etc. The stepper motors is ideal for precise positioning. You may have a fixed speed, variable speed, and position control. These motors are able to handle complex positions or movements. These devices offer power and precision in a compact sizes. These motors can take a great load. A good example to show this would be an escalator. Escalators are constantly worked and carry very heavy loads throughout the day. The step motor has to be able to take up to several hundreds of pounds maybe even thousands. The speed of the escalator is constant and never changes no matter how many people are on it. A different type of application could be an assembly line. This typically requires precise quick and place movements. Most stepper motor products are open loop systems, meaning there is no feedback info needed about the position. By keeping track of the input step pulses, the position is known. Some of the advantages of a stepper motor, but not limited to are: • Its input pulse is proportional to angle rotation • If windings are energized at stand sill the motor has full torque • Different rotation speeds are available since the frequency of input pulses are proportional to the speed. • It cost less to have open-loop control that responds to digital input pulses • Precise response time to starting, stopping, and reversing • No brushes within the motor making it more reliable. There are three different types of stepper motor models to choose from, the variable -reluctance, the permanent-magnet, and last but not least the hybrid step motor. The three all have different qualities for certain applications. The stepper motor has been around for a long time and are currently and will continue to be used throughout the world. No matter what the application will be the step motor will always rise to the occasion.

Stepper Motor Applications
One of the best, most flexible, computer-controlled positioning systems is one in which the stepper motor is integrated. Having more simple and hardy characteristics compared to a closed-loop servo system, stepper motor and driver systems are digitally controlled, and are a crucial element in the less costly open-loop system. Industrial applications for the stepper motor are in high-speed pick-and-place equipment and multi-axis CNC machines frequently drive lead screws or ballscrews directly. Usually, a stepper motor is often used in precision positioning in the fields of lasers and optics, often being used in linear actuators, linear stages, goniometers, mirror mounts, and rotation stages. The stepper motor is also used for positioning valve pilot stages for fluid control systems, and in packaging machinery. Traditionally, the stepper motor has been used commercially in floppy disk drives, and continues to be used for flatbed scanners, computer printers, plotters, slot machines, and a myriad of other devices. A stepper motor can be used to generate power as well, often designed in wind turbines and solar positioning systems.

Stepper Motor Driver Pack Used in Time Travel
Time is the centralized theme at the New Mexico Museum of Natural History in Albuquerque. At one point, the museum wanted to convey the idea that traveling through the exhibit is as if one is traveling through time. The museum depicted the conditions of New Mexico during the time periods of the Cretaceous period (75 million years ago) and the Tertiary period (37 million years ago), and how the area has evolved since. However, the museum did so with less than a satisfactory effect on the visitor. The idea they constructed to improve this was known as the Evolator. Derived from a combination of the words EVOLutionary and elevATOR, the evolator was an elevator-like vehicle that allowed visitors to be transported through time as evolution took place. It was designed by Art & Technology, Inc., in California, and is located between two exhibit areas in the museum. Allowing up to twenty people to enter from one exhibit into one door, experience time travel, and exit out the second door into another exhibit, it allows the passengers to experience 30 million years of time travel in six minutes. During time travel, the guests can view the outside world via TV screens, and see the two ports and the evolator traveling through rock strata on both sides of them. They can feel the vehicle moving throughout the tour, as it stops frequently throughout the trip for the computer to evaluate the rocks that are visible through the ports. In order to create the full time travel illusion, five laser disks, special lighting, a sound system, a hydraulic system for rocking the evolator floor and two silicon belts are needed. The 18 foot long silicon belts run as long continuous loops at a high speed during evolator movement, and slow to a stop as the evolator stops. In order for the operation to appear realistic, the belts have to operate in synchronism, a condition that is met by means of using large stepper motors. Due to the fact that the belts are very heavy, Anaheim Automation needed to develop a high- performance stepper motor Driver Pack (known as DPK Series) for the job. A computer was selected to coordinate the stepper motor, driver and controller system that makes the evolator work. The computer provides the DPK with clock and direction signals that trigger the stepper motor Driver Pack to operate the stepper motors, according to the required movements of the silicon belts. Time travel visitors were as thrilled with the success of the Evolator as were!

Although the stepper motor has been overshadowed in the past by servo systems for motion control, it has emerged as the preferred technology in more and more areas. The major factor in this trend towards the stepper motor is the prevalence of digital control, the emergence of the microprocessor, improved designed (i.e. high‐torque models), and lower cost. Today, stepper motor applications are all around us: they are used in printers (paper feed, print wheel), disk drives, clocks and watches, as well as used in factory automation and machinery. A stepper motor is most often found in motion systems requiring position control. Anaheim Automation’s cost‐effective stepper motor product line is the wise choice for both OEM and user accounts. Anaheim Automations customers for the stepper motor product line is diverse: industrial companies operating or designing automated machinery or processes involving food, cosmetics or medical packaging, labeling or tamper‐evident requirements, cut‐to‐length applications, assembly, conveyor, material handling, robotics, special filming and projection effects, medical diagnostics, camera tracking, inspection and security devices, aircraft controls, pump flow control, metal fabrication (CNC machinery), and equipment upgrades. Anaheim Automation, Inc. stepper motor product line integrates a matched stepper motor, driver and controller in one unit. This design concept makes selection easy, thus reducing errors and wiring time. With friendly customer service and professional application assistance, Anaheim Automation often surpasses the customers expectations for fulfilling specific stepper motor and driver requirements, as well as other motion control needs. Stepper Motors are Used in Many Industries Stepper motors have become an essential component to applications in many different industries. The following is a list of industries making use of stepper motors: • Aircraft – In the aircraft industry, stepper motors are used in aircraft instrumentations, antenna and sensing applications, and equipment scanning • Automotive – The automotive industry implements stepper motors for applications concerning cruise control, sensing devices, and cameras. The military also utilizes stepper motors in their application of positioning antennas • Chemical – The chemical industry makes use of stepper motors for mixing and sampling of materials. They also utilize stepper motor controllers with single and multi-axis stepper motors for equipment testing • Consumer Electronics and Office Equipment – In the consumer electronics industry, stepper motors are widely used in digital cameras for focus and zoom functionality features. In office equipment, stepper motors are implemented in PC-based scanning equipment, data storage drives, optical disk drive driving mechanisms, printers, and scanners • Gaming – In the gaming industry, stepper motors are widely used in applications like slot and lottery machines, wheel spinners, and even card shufflers • Industrial – In the industrial industry, stepper motors are used in automotive gauges, machine tooling with single and multi-axis stepper motor controllers, and retrofit kits which make use of stepper motor controllers as well. Stepper motors can also be found in CNC machine control • Medical – In the medical industry, stepper motors are utilized in medical scanners, microscopic or nanoscopic motion control of automated devices, dispensing pumps, and chromatograph auto-injectors. Stepper motors are also found inside digital dental photography (X-RAY), fluid pumps, respirators, and blood analysis machinery, centrifuge • Scientific Instruments –Scientific equipment implement stepper motors in the positioning of an observatory telescope, spectrographs, and centrifuge • Surveillance Systems – Stepper motors are used in camera surveillance

Basic Types
Each type of stepper motor varies per application by its construction and functionality. The three most common stepper motor types are Variable Reluctance, Permanent Magnet, and Hybrid Stepper Motors. Variable Reluctance (VR) Stepper Motor VR stepper motors are characterized as having multiple soft iron rotors and a wound stator. VR stepper motors generally operate on the basic principle of the magnetic flux finding the lowest reluctance pathway through a magnetic circuit. In general operation, VR stepper motors have relatively high step rates of 5 to 15 degrees and have no detent torque. The step angles taken in VR stepper motors are related to the number of teeth the stator and rotor have. The equation relating these two variables can be found in the formula section of this guide. How Does a Variable Reluctance Stepper Motor Work? Referring to Figure 1 on Page 2, the poles become magnetized when the stator windings are energized with DC current. With the poles becoming magnetized, the rotor teeth are now attracted to the energized stator poles and rotate to line up. With the windings around stator A becoming energized the rotor teeth become attracted allowing the poles to line up. When A’s windings become de-energized and B’s windings become energized, the rotor rotates to line its teeth with the stator teeth. This process continues in sequence with C, followed by D being energized allowing for the rotor to rotate. Brief Summary of Variable Reluctance Stepper Motors: • The rotor has multiple soft iron rotors with a wound stator • Least complex and expensive stepper motor • Large step angles • No detent torque detected in hand rotation of a de-energized motor shaft Permanent Magnet (PM) Stepper Motor PM stepper motors are comprised of permanent magnet rotors with no teeth, which are magnetized perpendicular to the axis of rotation. By energizing the four phases in sequence, the rotor rotates due to the attraction of magnetic poles. The stepper motor shown in Figure 2 on page 3 will take 90 degree steps as the windings are energized in clockwise sequence: ABAB. PM stepper motors generally have step angles of 45 or 90 degrees and step at relatively low rates. However, they exhibit high torque and good damping characteristics. Anaheim Automation carries a wide selection of PM stepper motors, ranging from 15 to 57mm in diameter. Brief Summary of Permanent Magnet (PM) Stepper Motors: • The rotor is a permanent magnet • Large to moderate step angle • Often utilized in computer printers as a paper feeder Hybrid Stepper Motors Hybrid stepper motors incorporate the qualities of both the VR and PM stepper motor designs. With the Hybrid stepper motor’s multi-toothed rotor resemblance of the VR, and an axially magnetized concentric magnet around its shaft, the Hybrid stepper motor provides an increase in detent, holding and dynamic torque. In comparison to the PM stepper motor, the Hybrid stepper motor provides performance enhancement with respect to step resolution, torque, and speed. In addition, the Hybrid stepper motor is capable of operating at high stepping speeds. Typical Hybrid stepper motors are designed with step angles of 0.9°, 1.8°, 3.6° and 4.5°; 1.8° being the most common step angle. Hybrid stepper motors are ideally suited for applications having stable loads with speeds under 1,000 rpm. There are key components which are influential of the running torque of a Hybrid stepper motor which are laminations, teeth and magnetic materials. Increasing the amount of laminations on the rotor, precision and sharpness of the rotor and stator teeth, and strength of magnetic material are all factors taken into account in providing optimal torque output for Hybrid stepper motors. Brief Summary of Hybrid Stepper Motors: • Smaller step angles in comparison to VR and PM stepper motors • Rotor is made of a permanent magnet with fine teeth • Increase in detent, holding and dynamic torque • 1.8° is the most common step angle NOTE: At Anaheim Automation, the 1.8 degree Hybrid stepper motor is the most widely stocked stepper motor type, ranging in NEMA frame sizes, 08 to 42. The Hybrid stepper motor can also be driven two phases at a time to yield more torque, or alternately one then two then one phase, to produce half-steps or 0.9 degree increments.

A stepper motor (also referred to as a step or stepping motor) is an electromechanical device achieving mechanical movements through conversion of electrical pulses. Stepper motors are driven by digital pulses rather than by a continuous applied voltage. Unlike conventional electric motors which rotate continuously, stepper motors rotate or step in fixed angular increments. A stepper motor is most commonly used for position control. With a stepper motor/driver/controller system design, it is assumed the stepper motor will follow digital instructions. One important aspect of stepper motors is their lack of feedback to maintain control of position. It is this lack of feedback which classifies stepper motors as open-loop systems.

Stepper Motor products are a type of digital device. Digital information is processed through the Stepper Motor products to accomplish an end result, in this instance, controlled motion.You can assume that Stepper Motor products will dependably follow digital instructions just as a computer is anticipated to. This is the unique feature for Stepper motors. Stepper Motor products are an electric power motor that is driven by digital pulses as opposed to a continuously applied voltage. Inherent in this concept is open-loop control, where a train of pulses converts into so many shaft revolutions, with each revolution requiring a given number of pulses. Each pulse equals one rotary increment, or step (hence, Stepper motors), which is only a portion of one finished rotation. As a result, counting pulses can be applied in Stepper Motor products to accomplish a ideal amount of shaft rotation. The count automatically represents how much movement has been achieved, without the demand for feedback information, as would be the instance in servo systems.

Common Causes for Failure
NOTE: Always read the specification sheet/user’s guide accompanying each product. Problem: Stepper motor wires were disconnected while the driver was powered up. Solution: Avoid performing any service to the stepper motor, driver or controller while the power is on, especially in regard to the motor connections. This precaution is imperative for both the driver and the technician/installer. Problem: The stepper motor has a shorted winding or a short to the motor case. Solution: It is likely you have a defective stepper motor. Do not attempt to repair motors. Opening the stepper motor may cause the motor to lose its magnetism, causing poor performance. Opening of the stepper motor case will also void your warranty. The motor windings can be tested with an ohmmeter. As a rule of thumb, if the stepper motor is a frame size of NEMA 08, 11, 14, 15, 17, 23, or 34 and the warranty period has expired, it is not cost-effective to return these stepper motors for repair. Contact the factory if you suspect a defective stepper motor that is still under warranty, or if the stepper motor is a NEMA frame size 42 or a K‐series motor. Problem: Environmental factors are less than ideal. Solution: Environmental factors such as welding, chemical vapors, moisture, humidity, dust, metal debris, etc., can damage the electronic components and the stepper motor. Protect drivers, controllers and stepper motors from environments that are corrosive, contain voltage spikes, or prevent good ventilation. Anaheim Automation offers products in several line voltage ranges, as well as splash‐proof, IP65 rated stepper motors. For wash‐down or explosion‐proof motors, contact the factory directly. For AC lines containing voltage spikes, a line regulator (filter) will likely be required. NOTE: If your application requires welding, or if welding is done in the same work environment, contact the factory for advice on how to protect the stepper motor driver and controller. Problem: The stepper motor is back‐driving the stepper driver. Solution: A stepper motor being turned by a load creates a back EMF voltage on the driver. Higher speeds will produce higher voltage levels. If the rotational speed gets excessively high, this voltage may cause damage to the driver. This is especially dangerous when the motor is back‐driven while the driver is still on. Place a mechanical stop or brake in applications which may be subject to these phenomena.

Common Causes for Failure
Common Causes for Stepper Motor and/or Stepper Driver Failure NOTE: Make sure to look over the specification sheet/users guide that accompanies each product Problem: Irregular or erratic stepper motor or drivers function. Solution: In terms of failures, this is the most common, and the hardest to detect. Start by checking to make sure that all connections are secured between stepper motors and drivers. Evidence like discoloration at the terminals/connections, may reveal a loose connection. Make certain to inspect all terminal blocks and connectors when exchanging a stepper motor, driver, or Driver Pack in a motion control system. Check cabling/wiring for precision. Stress stepper motor wiring and connections for worse problems and check with an ohmmeter. Problem: Stepper motor wires had been disconnected while the driver was powered up. Solution: Refrain from performing any service to the stepper motors or drivers as the power is on, especially in regard to motor connectors. This safety measure is not only to protect the specialist or installer, but will also to protect the driver. Problem: Bad system performance. Solution: Check to discover if the wire/cables are too long. Keep wire/cable to the stepper motors below 25 feet in length. For applications where the wiring from the stepper motors to the stepper drivers is higher than 25 feet, please contact the factory for instructions, as chances are that transient voltage protection devices are going to be required. Another likelihood is that the stepper motor lead wires are of a gauge that is far too small. Never match your cable wires to the gauge size of the stepper motor lead wires. Anaheim Automation advises using a shielded cable for such wiring (purchased separately). Because most stepper motors start to lose their magnetism over time of use, you should keep reports of how old each one is; as this can affect performance. Typically its possible to expect 10,000 operating hours for stepper motors (roughly 4.8 years, running one eight-hour shift every work day). Also, make certain that your stepper motor and driver combo is a beneficial match for your application. Contact the factory, should you have any worries. Problem: The stepper motor has a shorted winding or a short to the motor case. Solution: It is likely that you have a defective stepper motor. Do not attempt to repair motors. Opening the stepper motor case may de-magnetize the motor, leading to poor performance. Opening of the stepper motor case will also void your warranty. As an alternative, use an ohmmeter to test the motor windings. As a general guideline, if the stepper motor is a frame size of NEMA 08, 11, 14, 15, 17, 23, or 34 and the warranty period has expired, it is not cost-effective to return these stepper motors for service. Call the factory if you believe you have a defective stepper motor that is still under warranty, or if it is a NEMA size 42 or a K-series motor. Problem: The stepper motor driver or Driver Pack is over-heating. Solution: Air flow and cooling accommodations are vital : inability to provide adequate air flow will affect the stepper motor drivers overall performance and will shorten the life of the driver. Maintain driver temperatures below 60 degrees Celsius. To preserve good airflow: use fans, heat sink material, and base plates, so as not to exceed the optimum temperature rating of the stepper motors, drivers or controllers. Be mindful of temperatures inside cabinets and enclosures where stepper drivers may be attached. Problem: Environmental factors are less than ideal. Solution: Environmental factors, such as welding, chemical vapors, moisture, humidity, dust, etc., can damage both the electronics and the stepper motors. Protect drivers, controllers and stepper motors from environments that are corrosive, contain voltage spikes, orreduce good ventilation. Anaheim Automation offers products in a number of line voltage ranges. A line filtration system/regulator will probably be desired for AC lines that contain voltage spikes. Problem: Pulse rates (Clock or Step) to the driver are too high. Solution: The typical half-step driver can drive stepper motors at a top rate of 20,000 pulse per second. Pulse rates of above 60,000 pulses per second can impair the driver. The best combination of the motor and driver for the greatest performance is more clear in the individual specification sheets for each product. Problem: The stepper motor is stalling. Solution: Watch out for motors that stall, as it has the potential to damage the phase transistors on the driverby large voltage spikes. Some drivers are created to protect itself from such an event. If not, Transient Suppression Devices can be added externally. Seek advice from the factory for further information. Problem: The stepper motor is back-driving the driver. Solution: A stepper motor that is being turned with a load creates a back EMF current on the driver. Higher speeds will produce higher voltage levels. If the rotational speed should get very high, this voltage could potentially cause damage to the driver. This is especially dangerous when the motor is back-driven while the driver is on. Put a mechanical stop or brake in applications that might be subject to these phenomena. General Safety Considerations for Stepper Motor Applications The up coming safety considerations are required to be observed during all phases of operation, service and repair. Failure to comply with these safety measures violates protection standards of design, manufacture, and intended use of a Unipolar Stepper Motor, drivers and controllers. Anaheim Automation, Inc. takes on no responsibility for the customers failure to comply with thesespecifications. Even well built products, operated or installed inaccurately, can be hazardous. Safety measures must be observed by the user with caution to the load and operating environment. The customer is responsible for proper selection, installation and operation of the products purchased from Anaheim Automation, Inc. • Use care when handling, testing, and adjusting during installation, set-up and operation • Anytime power is applied, service should not be conducted • Be sure that the motor/driver has enough heat dissipation and air flow • Exposed circuitry should be effectively guarded or enclosed to counteract unauthorized human contact with live circuitry • It is important that all products be properly grounded and securely mounted • Elements including flammable gases, vapors, liquids or dust should not interact with motors in operation

Several choices for customization options for Stepper Motor products are accessible through Anaheim Automation. The variety of modifications includes, but is not confined to: shaft, brake, oil seal for an IP65 rating, mounting dimensions, speed, torque, and voltage. Contact Anaheim Automation today to set up an order for utilities with Stepper Motor products that require customization: 1-714-992-6990.

• Low efficiency (Motor attracts a substantial amount of power regardless of the load) • Torque drops rapidly with speed (torque is inversely proportional of speed) • Prone to resonance* (Microstepping allows for smooth motion) • No feedback to indicate missed steps • Low torque-to-inertia ratio • Cannot accelerate loads very rapidly • Motor gets very hot in high performance configurations • Motor will not “pick up” after momentary overload • Motor is noisy at moderate to high speeds • Low output power for size and weight *Resonance-is inherent in the design and operation of all stepping motors and occurs at specific step rates. It is the combination of slow stepping rates, high rotor inertia, and elevated torque which produce ringing as the rotor overshoots its desired angular displacement and is pulled back into position causing resonance to occur. Adjusting either one of the three parameters –inertial load, step rate, or torque- will reduce or eliminate resonance. In practical practice, the torque parameter is more controllable using microstepping. In microstepping mode, power is applied to the stator windings incrementally which causes torque to slowly build, reducing overshoot and therefore reducing resonance.

Environmental Considerations
The following environmental and safety considerations must be observed during all phases of operation, service and repair of a stepper motor system. Failure to comply with these precautions violates safety standards of design, manufacture and intended use of the stepper motor, driver and controller. Please note that even with a well‐built stepper motor, products operated and installed improperly can be hazardous. Precaution must be observed by the user with respect to the load and operating environment. The customer is ultimately responsible for the proper selection, installation, and operation of the stepper motor system. The atmosphere in which a stepper motor is used must be conducive to good general practices of electrical/electronic equipment. Do not operate the stepper motor in the presence of flammable gases, dust, oil, vapor or moisture. For outdoor use, the stepper motor, driver and controller must be protected from the elements by an adequate cover, while still providing adequate air flow and cooling. Moisture may cause an electrical shock hazard and/or induce system breakdown. Due consideration should be given to the avoidance of liquids and vapors of any kind. Contact the factory should your application require specific IP ratings. It is wise to install the stepper motor, driver and controller in an environment which is free from condensation, dust, electrical noise, vibration and shock. Additionally, it is preferable to work with the stepper motor/driver /controller system in a non‐static, protective environment. Exposed circuitry should always be properly guarded and/or enclosed to prevent unauthorized human contact with live circuitry. No work should be performed while power is applied. Don’t plug in or unplug the connectors when power is ON. Wait for at least 5 minutes before doing inspection work on the stepper motor system after turning power OFF, because even after the power is turned off, there will still be some electrical energy remaining in the capacitors of the internal circuit of the stepper motor driver. Plan the installation of the stepper motor, driver and/or controller in a system design that is free from debris, such as metal debris from cutting, drilling, tapping, and welding, or any other foreign material that could come in contact with circuitry. Failure to prevent debris from entering the stepper motor system can result in damage and/or shock.

Q: Why is the stepper motor size important? Is it possible to just choose a large motor size? A: The stepper motor size is important because if the motor’s rotor inertia predominately consists of the load, resonance increases and poses issues. Also, larger rotors require more time to accelerate and decelerate and therefore it is important to choose a motor size dependent on the criteria for user applications. Q: While increasing speed, why do stepper motors lose torque? A: Inductance is the leading cause for motors losing torque at high speeds. The electrical time constant, τ, is the amount of time it takes a motor winding to charge up to 63% of its rated value given a resistance, R, and inductance, L. With τ = R/L, at low speeds, high inductance is not an issue since current can easily flow through the motor windings quickly. However, at high speeds, sufficient current cannot pass through the windings quick enough before the current is switched to the next phase, thereby reducing the torque provided by the motor. Therefore, it is the current and number of turns in the windings which determines the maximum output torque in a motor, while the applied voltage to the motor and the inductance value of the winding will affect on the speed at which a given amount of torque can be produced. Q: Why does increasing the voltage increase the torque if stepper motors are not voltage driven? A: Voltage can be viewed as forcing current through the coil windings. By increasing voltage, pressure to force current through the coil also increases. Therefore, this vast amount of current being forced through the coil causes it to saturate which results in loss of torque and increase of speed. Q: What temperatures are stepper motors able to run at? A: Most stepper motors include Class B insulation. This allows the motor to sustain temperatures of up to 130° C. Therefore, with an ambient temperature of 40° C, the stepper motor has a temperature rise allowance of 90° C allowing for stepper motors to run at high temperatures. Q: Is it possible to get more torque by running the stepper motor at double its rated current? A: It is possible to increase torque by increasing the current but by doing so, it weakens the motor’s ability to run smoother. Q: What is the difference between four, six and eight leads in motors? A: Stepper motors have the capability to run in either parallel or series modes. In a parallel mode, only a four lead motor can be run while in a series mode a six lead motor can be run. Eight lead motors can run in either parallel or series configurations. In applications where more torque is required at higher speeds, a lower inductance value given from a four lead motor is better choice. Q: What is the difference between Unipolar and Bipolar motors? A: A unipolar wound motor has six lead wires with each winding having a center tap. Most applications implementing unipolar wound motors require high speed and torque. On the other hand, a bipolar wound motor has four lead wires with having no center tap connections. Most applications implementing bipolar wound motors require high torque at low speeds. Q: What is the difference between a closed-loop stepper motor controller and an open-loop stepper motor controller? A: In an open-loop stepper motor controller, no feedback is going from the motor to the controller. This type of controller is effective when the motor is carrying a constant load at a steady speed. A closed-loop motor controller is more applicable in applications where load or speed varies. In comparison to the closed-loop controller, the open-loop controller lacks complexity and is more affordable. Q: When should I use microstepping? A: Microstepping is typically used in applications which require the motor to operate at less than 700 pulses per second.

Drivers and indexers are often combined with Stepper Motor products for management. Stepper Motor Drivers, Stepper Motor Control Links, and Stepper Motor Controllers are among the main choices for types of command devices for Stepper Motor products. Adjustments such as the speed and direction of the Stepper Motor products is determined by these digital control devices. Figure 8 exhibits how these devices are set-up. To interpret feedback, the Stepper Driver connected to Stepper Motor products accepts the direction signals and also the clock pulse signals and translates them into phase currents. The Stepper Indexer can make the clock pulses and the direction signals for the Stepper Motor products. The computer or PLC (Programmable Logic Controller) sends out directions to the indexer.

Step angle calculation: φ=((N_s-N_r)/(N_s*N_r ))*360° φ = Step Angle Ns = Number of teeth on stator Nr = Number of teeth on rotor Steps per second = rpm * steps per revolution 60

General Safety Considerations
The following safety considerations are required to be observed during all phases of operation, service and repair. Failure to conform with these safety measures violates safety standards of design, manufacture, and designated use of Stepper Motor, drivers and controllers. Anaheim Automation, Inc. assumes no responsibility for the customers incapacity to comply with theserequirements. Even well-built products, operated or installed improperly, can be hazardous. Safety precautions must be observed by the user with regard to the load and operating environment. The customer is liable for appropriate selection, installation and operation of the products purchased from Anaheim Automation, Inc. • Use caution when handling, testing, and adjusting during installation, set-up and operation • Service must not be performed with power applied • Make sure the motor/driver has plenty of heat dissipation and air flow • Exposed circuitry should be properly guarded or enclosed to counteract unauthorized human contact with live circuitry • All products should be firmly mounted and effectively grounded • Elements such as flammable gases, vapors, liquids or dust should not interact with a stepper motor in operation NOTE: Please Use a RMA Form should you need to return a product for REPAIR. This form can be found in Support, Forms, RMA Request on this web site.

Bifilar Winding – refers to the winding configuration of a stepper motor where each stator pole has a pair of windings; the stepper motor will have either 6 or 8 lead wires, depending on termination. This wiring configuration can be driven from a unipolar or bipolar driver. Clock – a pulse generator, which controls the timing of switching circuits that control the speed of the step motor. Closed-Loop – a system with a feedback type of control, such that the output is used to modify the input. Controller (Stepper Motor) – a regulating mechanism; essentially a DC power supply plus power switching with associated circuits for controlling the switching in the proper sequence. Detent Torque – is the holding torque when no current is flowing in the motor. The maximum torque which can be applied to the shaft of an unenergized step motor without causing continuous rotation. The minimal torque present in an unenergized motor. The detent torque of a step motor is typically about 1% of its static energized torque. Driver (Stepper Motor) – often referred to as a translator, drives a step motor based on pulses from a clock, pulse generator, or computer. Translates the train of pulses and applied power to the appropriate step motor windings. Dynamic Torque – the torque developed by a motor while stepping at low rates. Encoder – often called a pulse generator, is a feedback device for step motors. It consists of a disc, vane, or reflector attached to a step motor shaft to provide digital pulses, which are provided to a translator and /or counters. This provides positional information if fed into a counter. Speed information may be derived if the time between successive pulses is measured and decoded. Holding Torque – the maximum torque that can be externally applied to the step motor shaft without causing continuous rotation when one or more phases of the motor are energized. Inertia – is a measure of an object’s resistance to a change in velocity. Maximum Running Torque – the maximum torque load that the motor can drive without missing a step. This typically occurs when the windings are sequentially energized at approximately 5 pps. Open-Loop – refers to a motion control system where no external sensors are used to provide position or velocity correction signals. Permanent Magnet Stepper Motor – a step motor having permanent magnet poles. Pole – the part of a magnetic circuit where a magnetic pole is generated either by a permanent magnet or by windings. Pulse – an electrical signal or voltage of short duration, used in conveying intelligence. Rated Torque – the torque-producing capacity of a motor at a given speed. This is the maximum torque the motor can deliver to a load and is usually specified with a torque/speed curve. Resolution – the smallest positioning increment that can be achieved. It is frequently defined as the number of steps required for a motor’s shaft to rotate one complete revolution. The reciprocal of the number of steps per revolution of the motor. Rotor – the rotating part of the motor (the shaft may be included). Stator – the stationary magnetic parts of the motor including the windings. Step – movement of the rotor from one energized position to the next. Step Angle – the nominal angle through which the shaft of a step motor turns between adjacent step positions. It depends upon the motor and driving sequence (mode of drive). Step Increment – an indication of step or motion size. Usually this is specified in degrees for a rotary motor and inches or millimeters for a linear motor. Step (Stepping, Stepper) Motor – a digital actuator, which operates from discrete pulses (input signals) and produces motion in discrete increments. May be rotary or linear increment. Step Position – the angular position that the shaft of an unloaded step motor assumes when energized. The step position is not necessarily the same as the detent position. Teeth – projections on both rotor and stator such that when aligned they produce a low reluctance magnetic path. Torque – a force or couple tending to, or producing, rotation. Common step motor torque units are oz-in, N-m, or mNm. Train Pulse – a series of spaced pulses. Unifilar Winding – refers to the winding configuration of the stepper motor where each stator pole has one set of windings; the stepper motor will have only 4 lead wires. This winding configuration can only be driven from a bipolar driver. Variable Reluctance Step Motor – a step motor having only soft iron poles.

How Does a Stepper Motor Work
The main use of the stepper motor is to control motion, whether it is linear or rotational. In the case of rotational motion, receiving digital pulses in a correct sequence allows the shaft of a stepper motor to rotate in discrete step increments. A pulse (also referred to as a clock or step signal) used in a stepper motor system can be produced by microprocessors, timing logic, a toggle switch or relay closure. A train of digital pulses translates into shaft revolutions. Each revolution requires a given number of pulses and each pulse equals one rotary increment or step, which is only a portion of one complete rotation. There are numerous relationships between the motors shaft rotation and input pulses. One such relationship is the direction of rotation and the sequence of applied pulses. With proper sequential pulses being delivered to the device, the rotation of the shaft motor will undergo a clockwise or counterclockwise rotation. Another relation between the motor’s rotation and input pulses is the relationship between frequency and speed. Increasing the frequency of the input pulses allows for the speed of the motor shaft rotation to increase.

How is a Stepper Motor Controlled
A stepper motor performs the conversion of logic pulses by sequencing power to the stepper motor windings; generally, one supplied pulse will yield one rotational step of the motor. This precision is provided by a stepper driver, which is able to control speed and positioning of the motor. The stepper motor increments a precise amount with each control pulse, converting digital information into exact incremental rotation without the need for feedback devices, such as tachometers or encoders. Since the stepper motor/driver is an open-loop system, the problems of feedback loop phase shift and resultant instability, common with servo motor/drive systems, are eliminated.

How to Select
There are several important criteria involved in selecting the proper stepper motor: 1. Desired Mechanical Motion 2. Speed Required 3. Load 4. Stepper Mode 5. Winding Configuration With appropriate logic pulses, stepper motors can be bi-directional, synchronous, provide rapid acceleration, run/stop, reversal, and can interface easily with other digital mechanisms. Characterized as having low-rotor moment of inertia, no drift, and a noncumulative positioning error, a stepper motor is a cost-effective solution for many motion control applications. Generally, stepper motors are operated without feedback in an open-loop fashion and sometimes match the performance of more expensive DC Servo Systems. As mentioned earlier, the only inaccuracy associated with a stepper motor is a noncumulative positioning error measured in % of step angle. Typically, stepper motors are manufactured within a 3-5% step accuracy. Motion requirements, load characteristics, coupling techniques, and electrical requirements need to be understood before the system designer can select the best stepper motor/driver/controller combination for a specific application. While not a difficult task, several key factors need to be considered when determining an optimal stepper motor solution. The system designer should adjust the characteristics of the elements under his/her control, to meet the application requirements. Anaheim Automation offers many options in its broad line of stepper motor products, allowing for the maximum amount of design flexibility. Although it may appear overwhelming to choose, the result of having a large number of options is a high-performance system that is cost-effective. Elements needed to be considered include the stepper motor, driver, and power supply selections, as well as the mechanical transmission, such as gearing or load weight reduction through the use of alternative materials. Some of these relationships and system parameters are described in this guide. Inertial Loads Inertia is a measure of an object’s resistance to a change in velocity. The larger an object’s inertia, the greater the torque is required to accelerate or decelerate it. Inertia is a function of an object’s mass and shape. A system designer may wish to select an alternative shape or low-density material for optimal performance. If a limited amount of torque is available in a selected system, then the acceleration and deceleration times must increase. For most efficient stepper motor systems, the coupling ratio (gear ratio) should be selected so the reflected inertia of the load is equal to, or greater than, the rotor inertia of the stepper motor. It is recommended that this ratio not be less than 10 times the rotor inertia. The system design may require the inertia to be added or subtracted by selecting different materials or shapes of the loads. NOTE: The reflected inertia is reduced by a square of the gear ratio, and the speed is increased by a multiple of the gear ratio. Frictional Loads All mechanical systems exhibit some frictional force. The designer of a stepper motor system must be able to predict elements causing friction within the system. These elements may be in the form of bearing drag, sliding friction, system wear, or the viscosity of an oil filled gear box (temperature dependent). A stepper motor must be selected that can overcome any system friction and still provide the necessary torque to accelerate the inertial load. NOTE: Some friction is desired, since it can reduce settling time and improve performance. Positioning Resolution The positioning resolution required by the application may have an effect on the type of transmission used, and/or selection of the stepper motor driver. For example: A lead screw with 5 threads per inch on a full-step drive provides 0.001 inch/step; half-step provides 0.0005 inch/step; a microstep resolution of 25,400 steps/rev provides 0.0000015 inch/step.

The typical lifetime for a stepper motor is 10,000 operating hours. This approximates to 4.8 years; given the stepper motor operates one eight-hour shift per day. The lifetime of a stepper motor may vary in regards to user application and how rigorous the stepper motor is run.

Stepper motors are driven by waveforms which approximate to sinusoidal waveforms. There are three excitation modes commonly used with stepper motors which are full‐step, half‐step and microstepping. Stepper Motor ‐ Full‐Step (Two Phases are on) In full‐step operation, the stepper motor steps through the normal step angle, e.g. with a 200 step/revolution the motor rotates 1.8° per full step, while in half‐step operation the motor rotates 0.9° per full step. There are two kinds of full‐step modes which are single-phase full-step excitation and dual-phase full-step excitation. In single-phase full‐step excitation, the stepper motor operates with only one phase energized at a time. This mode is typically used in applications where torque and speed performances are less important, wherein the motor operates at a fixed speed and load conditions are well defined. Typically, stepper motors are used in full‐step mode as replacements in existing motion systems, and not used in new developments. Problems with resonance can prohibit operation at some speeds. This mode requires the least amount of power from the drive power supply of any of the excitation modes. In dual-phase full‐step excitation, the stepper motor operates with two phases energized at a time. This mode provides excellent torque and speed performance with minimal resonance problems. NOTE: Dual excitation provides about 30 to 40 percent more torque than single excitation, but does require twice the power from the drive power supply. Many of Anaheim Automation’s microstepping drivers can be set to operate at full‐step mode if necessary. Stepper Motor ‐ Half‐Step Stepper motor half‐step excitation mode alternates between single and dual-phase operations resulting in steps that are half the normal step size. Therefore, this mode provides twice the resolution. While the motor torque output varies on alternate steps, this is more than offset by the need to step through only half the angle. This mode had become the predominately used mode by Anaheim Automation beginning in the 1970’s, because it offers almost complete freedom from resonance issues. The stepper motor can operate over a wide range of speeds and drive almost any load commonly encountered. Although half‐step drivers are still a popular and affordable choice, many newer microstepping drivers are cost‐effective alternatives. Anaheim Automation’s BLD75 series is a popular half-step driver and is suitable for a wide range of stepper motors. Stepper Motor ‐ Microstepping In the stepper motor microstepping mode, a stepper motors natural step angle can be partitioned into smaller angles. For example: a conventional 1.8 degree motor has 200 steps per revolution. If the motor is microstepped with a divide‐by‐10, then each microstep moves the motor 0.18 degrees, which becomes 2,000 steps per revolution. The microsteps are produced by proportioning the current in the two windings according to sine and cosine functions. This mode is widely used in applications requiring smoother motion or higher resolution. Typical microstep modes range from divide‐by‐10 to divide‐by‐256 (51,200 steps per revolution for a 1.8 degree motor). Some microstep drivers have a fixed divisor, while the more expensive microstep drivers provide for selectable divisors. For cost‐effective microstep drivers, see Anaheim Automation’s MBC and MLA Series. NOTE: In general, the larger the microstep divisor provided, the more costly will be the stepper motor driver. Should you prefer, Anaheim Automation also manufactures a series of Integrated Stepper Motors/Drivers, meaning the stepper motor and driver are in one unit. This design approach takes the guesswork out of motor and driver compatibility. For more information, please see the 17MD, 23MD and 34MD Series.

Stepper Motor products have three often affiliated excitation modes. The Stepper Motor modes include the full-step, half-step and micro-step. Stepper Motor - Full-Step: In whole step operation, Stepper Motor products step in the normal step angle e.g. 200 step/revolution motors take 1.8 steps while in half step operation, 0.9 steps are taken. There are two kinds of full-step modes. Single phase full-step excitation is when Stepper Motor products are run with only one phase energized at a time. This mode must only be used where the motor is operated with load conditions that are well defined and at a fixed rate, such as where torque and speed performance is not essential. Difficulties with resonance can stop operation at some speeds. This unique form of mode requires the least amount of power from the drive power supply of any of the excitation modes. Dual phase full-step excitation is simply when the Stepper Motor products are controlled with two phases energized at-a-time. Other than its small amount of resonance problems, this mode provides good torque in addition to speed performance. Dual excitation requires double the power from the drive power supply, but provides about 30-40% extra torque than single excitation. Stepper Motor - Half-Step: The option for half-step excitation in Stepper Motor products provides two times the resolution. It results in steps that are add up to one half of the normal step size by usingalternative single and dual phase operation. This setting is great because the motor only needs to step through only have the angle, even though the motor torque end result varies on alternate steps. This mode is becoming the predominately used mode by Anaheim Automation because it offers almost complete freedom from resonance problems. Stepper Motor products are usually operated over a wide range of speeds and also used to drive almost any kind of load commonly experienced. Stepper Motor - Micro-Step: Within Stepper Motor products micro-step mode, a Stepper Motors natural step angle can be divided into much smaller angles. To show this, the 200 steps per revolution that natural Stepper motors begin with (1.8°) can be divided by 10 if it is micro-stepped; therefore creating 2,000 steps per revolution with each micro-step equalling 0.18°. For a 1.8° motor, if there are 51,200 steps per revolution, then micro-step modes can range from being divided by 10 to to be divided by 256. The micro-steps are maded by proportioning the current in the two windings relating to sine and cosine functions. This mode is entirely used where smoother motion or more resolution is essential.

Motor Windings Configuration
Stepper motors are wound on the stator poles in either a unifilar or bifilar configuration. The term unifilar winding refers to the winding configuration of the stepper motor where each stator pole has one set of windings; the stepper motor will have only 4 lead wires. This winding configuration can only be driven from a bipolar driver. The term bifilar winding refers to the winding configuration of a stepper motor where each stator pole has a pair of identical windings; the stepper motor will have either 6 or 8 lead wires, depending on termination. This type of winding configuration simplifies operation in that transferring current from one coil to another, wound in the opposite direction, will reverse the rotation of the motor shaft. Unlike the unifilar winding which can only work with a bipolar driver, the bifilar winding configuration can be driven by a unipolar or bipolar driver.

Physical Properties
The main components used in a stepper motor are the shaft, rotor and stator laminations, magnets, bearings, copper wires and lead wires, washers, and front and end covers. Most shafts of a stepper motor are made of stainless steel metal, while the stator and the rotor laminations are comprised of silicon steel. The silicon steel allows for higher electrical resistivity which lowers core loss. The various magnets available in stepper motors allow for multiple construction considerations. These magnets are ferrite plastic, ferrite sintered and Nd-Fe-B bonded magnets. The bearings of a stepper motor vary with size of the motor. The housing materials are composed of various other metals like aluminum, which allow for high resistance to heat.

How does a stepper motor move? A. Electrical Pulse B. Continuous Applied Voltage C. Alternates from A and B A pulse can be produce by which means? A. Microprocessor B. Timing Logic C. Toggle Switch D. All of the above Which of the following is not a type of stepper motor? A. Variable Reluctance B. Hybrid C. Magnetic D. Lead-Screw Which of the following is not a component of a stepper motor? A. Windings B. Rotor and Stator C. Commutator D. Brush E. Both C and D What is the difference between full-step and half-step? A. In full-step two phases are on and in half-step only one phase is on. B. More resonance is evident in half-step C. More power required for full-step D. Half-step offers better resolution List industries that use stepper motors in their applications: What criteria’s are necessary to consider when selecting a stepper motor? A. Mechanical Motion B. Inertial Load C. Speed Requirements Which of the following is NOT an advantage of stepper motors? A. Cost-efficient B. Maintenance-free C. No feedback D. More complex circuitry With a stator having 8 teeth and a rotor having 6 teeth, what step angle will an application be able to achieve? A. 15° B. 51° C. 20° D. 105° If an application using a stepper motor required feedback, which device would be needed to accomplish this? A. Encoder B. Linear Guide C. Commutator D. Counter

Characteristics of a Step Motor
• Step motors are constant power devices. • As the step motor speed increases, torque decreases. • Maximum torque for most step motors is when the motor is stationary, but the important aspect of the step motor is the torque when rotating (spinning). • Torque curves (performance curve of a specific step motor) can be extended by current limiting step motor drivers (see our web site for compatible step motor and driver models). • Step motors exhibit some vibratory characteristics, more than other motor types. (If vibration is a problem, consider another technology). • The vibration seen in a step motor is due to the fact that the takes discrete �steps� and this tends to create a snap in the step motor rotor, as it moves from one position to the other. • Proper sizing and pairing the step motor with the step motor driver will help reduce vibration • Failure to correctly size a step motor application can cause the motor to lose torque and change direction, at certain speeds. (This problem can be greatly reduced or eliminated by accelerating quickly the speeds that are problematic. Frictional damping the step motor system or using a micro step motor driver combination may completely solve this problem. • Step motor types that are constructed with a high amount of phases are capable of smoother operation, or the same effect can be accomplished using a microstep drive technique. Anaheim Automation carries a broad line of step motor, as well as step motor drivers and controller. Specials and customization services are also available, should your application require an exact step motor specification.

Lead Stepper Motor is the Best Option
Have you wondered why Anaheim Automation carries the most stock in the eight-lead stepper motor configuration than the six or four lead configurations? An eight-lead stepper motor is wound like a unipolar stepper motor, but the difference is that the leads are not connected (joined) to the common internally to the motor. The flexibility of the eight-lead stepper motor is in that it can be configured in several different ways: • Unipolar • Bipolar with single winding per phase, which will run the stepper motor on half of the windings available, reducing the available low speed torque, but requires less current to operate. • Bipolar with SERIES windings, which provides higher inductance, but lower current per winding • Bipolar with PARALLEL windings, which requires a higher current, but outperforms because the winding inductance is reduced. The many configurations of the eight-lead stepper motor make it a logical choice for Anaheim Automation to stock, as it is cost-effective to manufacture and serves a wide range of customers and stepper motor applications.

Electric Motor Types
Electric motors are typically classified by motor type, i.e. Alternating Current (AC) versus Direct Current (DC). This distinction is not always so rigid, in that many classic DC motors run on AC power. This type of electric motor is referred to as universal motors. Some industries used the rated output power specification of the motor to categorize motor types. For example, those motor of less than 746 Watts are often referred to as fractional horsepower (FHP). In more recent years, the trend toward electronic control further muddles the electric motor distinctions, as modern motor drivers and controllers have moved the commutator out of the motor casing. For this newer type of motors, driver and controller circuits are relied upon to generate sinusoidal AC drive currents. Examples of such are: the Blushless DC Motor (BLDC) and the Stepper Motor, both being poly-phase AC motors requiring external electronic control. Although historically, stepper motors (such as for maritime and naval gyrocompass repeaters) were driven from DC switched by contacts. Considering all rotating (or linear) electric motors require synchronism between a moving magnetic field and a moving current sheet for average torque production, there is a clearer distinction between an asynchronous and synchronous types. An asynchronous motor requires slip between the moving magnetic field and a winding set to induce current in the winding set by mutual inductance; the most ubiquitous example being the common AC Induction Motor which must slip to generate torque. In the synchronous types, induction (or slip) is not a requisite for magnetic field or current production. See the chart below to help determine if a stepper motor, Brush or BLDC motor, AC or Servo is the correct motor choice for your application.

Harnessing the Benefits of Open Loop Systems
A stepper motor in open-loop systems can provide accurate, dependable speed and positioning that can equal the best servo performance if installed correctly. Their simplicity allows them to function without tachometers, encoders, or other drawbacks that add to the cost of operation. Proper installation also makes it easy to pinpoint the exact effect of the operation, since they increment a precise amount with each control pulse. Likewise, the rate of control pulses determines motor speed so it too is totally predictable. Therefore, in the right mechanical environment, stepper motor systems can provide whatever degree of accuracy and reliability that is required. Designing a System: A stepper motor has several usage benefits over servos, the first being cost. In almost any application, stepper motor can be used at a fraction of the cost of servo. With servo drives, the problem of feedback loop phase shift and instability is common. However, the stepper motor is an open-loop system that completely void any potential problem that could arise in this area. The initial design phase for open-loop systems is similar to that of the servo system. Load characteristics, performance requirements, and mechanical design, including coupling techniques, must be thoroughly considered before a designer can effectively select the best appropriate stepper motor and driver combination for an application. Once these factors have been determined, the motor specifications and system motion controller, such as a computer or PLC, can be established. Then the design comes down to selecting the suitable driver and controller to produce the motion necessary for the application. Defining a Driver Pack: In order to obtain an optimum solution, the following factors must be considered: 1. Begin with the stepper motor(s) and controller you have selected for your application. 2. Make use of one driver for each motor. The driver must match the motor current (amps per phase). 3. Include a power supply that supports the driver(s) and motor(s). 4. Select an interface to handle communications between the control device and the indexer (parallel, RS422, RS232C, serial, PLC, or manual switches). 5. Configure the Driver Pack with items 2 through 4 as applicable, or see Driver Packs on our website. NOTE: When the wiring from a driver to a stepper motor extends beyond 25 feet, consult Anaheim Automation for additional assistance. Shielded motor cable is available and purchased separately.

How to Measure Torque Requirements
The primary question Anaheim Automation needs answered regarding the application of a stepper motor is, What is the torque requirement of the mechanism driven? Accurate measurements of the torque requirements will facilitate in the selection of a stepper motor and driver/controller. A torque wrench is perhaps the easiest method to determine torque. The wrenchs gauge will indicate the torque measurement in units of ounce-inches or pound-inches. A torque watch can also be used; it is an instrument that works similarly to a torque wrench and attaches to the end of a shaft. A torque watch can be purchased at locations where precision instruments are sold. Another way to measure torque is the old fish scale method, which involves purchasing a spring scale and a pulley to fit the desired shaft. First mount the pulley onto the shaft, securing a strong string to the pulley. Wind the string around the pulley a few times, attaching the other end to the scale. Continue to pull on the string until the shaft begins to turn. The torque in pound inches is determined by multiplying the force in pounds displayed on the scale, with the radius of the pulley in inches. The radius of the pulley is the distance between the shafts center and the string wound around the pulley. This crude method can be used to determine both the starting and running torque; depending on how precisely the test is conducted. The same task can be performed without a spring scale, simply by getting the shaft to turn by adding more weight. Then place the weight on a scale and multiply the pounds or ounces times the radius in inches to determine the torque. If unsure in how to select an appropriate stepper motor for your application, contact our Applications Department.

Preset Indexer Driver Packs Provide Precision for Automatic Rubber Cutters
Most people do not realize the precision that goes into the manufacturing of products like oil filter rings, small drive and timing belts, and other similar rubber parts; engineers work to ensure they will perform correctly. The necessity to produce a reliable part substantially increases the cost of the good in which the product is installed in. Therefore, manufacturers using these parts need a quick, efficient way of producing them. A line of automatic rubber cutters ranging all the way from a simple, lathe-like machine up to a four spindle model is manufactured by one of our first customers. The line consists of numerous degrees of automation, one model having the capability to load a machine, cut parts, eject scrap into a waste bin, and place cut parts in a shipping container. Another model can cut double angles to make beveled edges, V-belt configurations, etc. Raw rubber comes in a tube-like shape that conforms to specified dimensions. The lengths of the tube are placed on mandrels and turned, much like a work piece in a lathe. To make cuts that produce the parts, a cutting mechanism stops at specified intervals as it travels along the tube. An Anaheim Automation stepper motor Driver Pack is used to accomplish exact precision when controlling the stepper motor; it positions the cutter as it travels along the tube. The stepper motor Driver Pack contains a preset indexer, a high performance bi-level stepper motor driver, and a matched power supply, all included in a small compact unit that is housed conveniently in the machines control panel. While the stepper motor Driver Pack takes care of actual positioning, the operator dials the specified width directly on the thumbwheel switches. The width of the cut can range from a thousandth of an inch to up to the length of the tube. The machines have the ability to index and cut up to 240 times a minute on each spindle. The control phase of manufacturing becomes significantly easier with the use of stepper motor Driver Packs, and allows for fast, dependable operation for the customers.

Coded Motor Cable
Anaheim Automations color-coded motor cable is available with aluminum foil shielding and a drain wire. This attribute forces noise to ground, protecting the stepper motor driver signals against corruption (electrical noise) and possible subsequent system failures. Shielded, color-coded motor cable is correctly sized (several gauges are offered), available in four, six or eight size conductor types with PVC insulation. The conductors are color-coded to match the leads on many Anaheim Automation standard stepper motor series, i.e. the D series stepper motor sequence (red/white, green, green/white, black, white). Color-coding the stepper motor cable has significantly reduced mistakes in the field by assuring the use of the correct wire gauges and preventing stepper motor leads from crossing. Due to the fact that stepper motor cables have eliminated many complications, we strongly recommend purchasing Anaheim Automated color-coded stepper motor cable for all motor driver installations. Available in one-foot increments, stepper motor cable is a small investment that will reap big rewards; it will help you protect your motion system.

Stepepr Motor Ratings and Specifications
Usually, stepper motor nameplates only indicate the winding current, and on some occasions, the voltage and wind resistance. The rated voltage of a stepper motor will generate the rated winding current at DC, but this information proves futile; the stepper motor driver voltages surpass the stepper motor rated voltage. The current and the low speed torque of a stepper motor have a direct relationship and need to be considered for optimal systems performance. The winding inductance and drive circuitry, especially the driving voltage, determines how rapid the stepper motor torque falls off at quicker speeds. The published torque curve should be used to determine how the stepper motor should be sized. This is noted by the manufacturer at certain drive voltages, and/or using their own driver circuitry. The two should be carefully chosen due to the fact that here is no guarantee for how adequate the performance will be given different driver circuitry.

Stepper Motor Accuracy and Resolution
The stepper motor is a component used in functions pertaining to open loop positioning and velocity. Ultimately, the systems accuracy depends on the stepper motor and the drives precision and behavior, because there is not feed-back transducer. Microstepping, precision sine/cosine current references, and second order damping have allowed the stepper motor to become the ideal candidate for applications dealing with precision control. Disregarding the drive, the stepper motor has distinct qualities that must be considered in regard s to accuracy in any application. A stepper motor is assembled to a certain tolerance. Usually, a standard stepper motor has a tolerance of +/- 3% non accumulative error regarding any steps location. In other words, on a typical 200 step per revolution stepper motor, teach step will be within 0.18-degree error range. The stepper motor can essentially resolve 2000 radial locations, accurately. Incidentally, this is the 10 microstep drives resolution. Beyond the resolution of 10, i.e. 125, there is no real additional accuracy (there may be more smoothness, but no increase in accuracy). Similarly, a voltmeter that displays 6 digits while having 1% accuracy only contains significant information in the first two digits. Two exceptions allow for higher resolutions: a stepper motor that runs in a closed-loop application with a high-resolution encoder, or an application that needs to operate smoothly at extremely low speeds (fewer than 5 full steps per second). Motor linearity is another factor that affects accuracy. Motor linearity is how the stepper motor operates between step locations. For every step pulse sent to a 10 microstep drive, a typical 1.8 per step motor should move precisely 0.18 degrees. Every stepper motor does face non-linearity; microsteps refuse to evenly spread themselves over a full step, and instead bunch together. Typically two effects may occur: deceleration where the microsteps bunch up and cyclic acceleration where the microsteps spread apart cause dynamically low speed resonances. Statically, the stepper motor position is not optimum.

Problem: Intermittent or erratic stepper motor or stepper driver function. Solution: This is the most common cause of failure and one of the most difficult to detect. Start by checking to ensure all connections are tight between the stepper motor and the stepper driver and controllers. Evidence of discoloration at the terminals/connections, may indicate a loose connection. When replacing a stepper motor, stepper driver or driver pack, or controller in a motion control system, and be sure to inspect all terminal blocks and connectors. Check cabling/wiring for accuracy. Stress stepper motor wiring and connections for poor conditions and check with an ohmmeter. Whenever possible, use Anaheim Automation’s shielded cables for stepper motor wiring. Problem: Poor system performance. Solution: Check to see if the wire/cables are too long. Keep stepper motor wire/cables less than 25 feet in length. For applications where the wiring from the stepper motor to the stepper driver exceeds 25 feet, please contact the factory for instructions, as it is likely that transient voltage protection devices will be required. Another possibility is the stepper motor lead wires are of a gauge too small. Do not match your cable wires to the gauge size of the stepper motor lead wires, this is a common mistake. To avoid this mistake, Anaheim Automation suggests using its shielded cable for such wiring purposes (purchased separately). Additionally, check the age of your stepper motor, as with time and use, stepper motors lose a portion of their magnetism which affects performance. Typically one can expect 10,000 operating hours for stepper motors (approximately 4.8 years, running a one eight‐hour shift per work day). Also, make certain your stepper motor and driver combination is a good match for your application. Contact the factory should you have any concerns. Problem: The stepper motor is stalling. Solution: In some cases, stalling of a stepper motor causes a large voltage spike that often damages the phase transistors on the driver. Some drivers are designed to protect themselves from such occurrences. If not, Transient Suppression Devices can be added externally. Consult the factory for further information. Stepper Motor Wiring: The following information is intended as a general guideline for wiring of the Anaheim Automation stepper motor product line. Be aware when you route power and signal wiring on a machine or system; radiated noise from the nearby relays, transformers, and other electronic devices can be introduced into the stepper motor and encoder signals, input/output communications, and other sensitive low-voltage signals. This can cause system faults and communication errors. WARNING – Dangerous voltages capable of causing injury or death may be present in a stepper motor system. Use extreme caution when handling, wiring, testing, and adjusting during installation, set‐up, tuning, and operation. Don’t make extreme adjustments or changes to the stepper motor system parameters, which can cause mechanical vibration and result in failure and/or loss. Once the stepper motor is wired, do not run the stepper driver by switching On/Off the power supply directly. Frequent power On/Off switching will cause fast aging of the internal components, which will reduce the lifetime of the stepper motor system. Strictly comply with the following rules: • Follow the wiring diagram for each stepper motor • Route high‐voltage power cables separately from low‐voltage power cables • Segregate input power wiring and stepper motor power cables from control wiring and motor feedback cables as they leave the stepper motor driver. Maintain this separation throughout the wire run • Use shielded cable for power wiring and provide a grounded 360 degree clamp termination to the enclosure wall. Allow room on the sub‐panel for wire bends • Make all cable routes short as possible NOTE: Factory-made cables are recommended for use in our stepper motor and driver systems. These cables are purchased separately, and are designed to minimize EMI. These cables are recommended over customer‐built cables to optimize system performance and to provide additional safety for the stepper motor system and the user. WARNING – To avoid the possibility of electrical shock, perform all mounting and wiring of the stepper motor and driver system prior to applying power. Once power is applied, connection terminals may have voltage present.

Because Stepper Motor products fluctuate in the way they perform and the way they are constructed, they are broken down into three basic varieties. Each of these designs of Stepper Motor products offers an alternative to an application in a different way. The three basic types of Stepper Motor products consist of the Variable Reluctance, Permanent Magnet, and Hybrid. Variable Reluctance (VR) Stepper Motor products: Variable Reluctance Stepper Motor products are recognized for possessing soft iron multiple rotor and a wound stator. The Variable Reluctance Stepper Motor products hold no detent torque. They typically operate in step angles from 5 to 15° at fairly high step rates. The four teeth line up with the four stator teeth of phase A by magnetic attraction when phase A is stimulated; as shown in figure 5. The next step is taken when A is switched off and phase B is energized, spinning the rotor clockwise 15°; Continuing the sequence, C is turned on next and then A again. If you change it so that the phase arrangement is reversed, the rotation will rotate counter clockwise. Permanent Magnet (PM) Stepper Motor products: The second type of Stepper Motor products are classified as the Permanent Magnet Stepper motors.These Stepper Motor products are diverse from the other two due to the fact that they have permanent magnet rotors and no teeth; the rotors are magnetized perpendicular to the axis. The rotor is attracted to the magnetic poles and as a result it rotates, when the four phases are energized in sequence. The motor will take 90 degree steps as the windings are energized in sequence ABCD, as shown in Figure 6. Permanent Magnet Stepper Motor products generally have step angles of 45 to 90 degrees and have a tendency to step at relatively low rates, but generate high torque and excellent damping characteristics. Hybrid Stepper Motor products: Hybrid Stepper Motor products combine qualities from the permanent magnet as well as variable reluctance Stepper Motor products. Here are some likable features of Hybrid Stepper Motor products which are from each: These Stepper Motor products have an exceptional holding and dynamic torque, a high detent torque, and theyll operate in high Stepper speeds. Step angles of 0.9 to 5.0 degrees are normally seen in Hybrid Stepper Motor products. In order for a single power supply to be used to power the motor, Bi-filar windings are supplied to these Stepper Motor products. The rotor should rotate in increments of 1.8 degrees if the phases are energized one at a time in the order they are indicated at. These Stepper Motor products may be driven in two phases at a time to yield more torque. Hybrid Stepper Motor products can be be driven by one then two then one phase to make half steps of 0.9 degree increments.

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