Posts Tagged 'DC Motor'

Highly Dynamic Brushless DC motors; Compact yet powerful

In automation and robotics, many applications are characterized by high energy and high torque at the same time.  Spatial restrictions also mean that drives must be short, have a long service life and be maintenance-free.  The newly redesigned EC-i motors from maxon motors offer solutions that fit these requirements perfectly.
Maxon EC-i Motor

Maxon EC-i Motor

These brushless DC motors have several key advantages: low inertia, minimal detent, robust bearings and compact construction.  The use of high-powered permanent magnets ensures high power density, providing great speed stability under load.

These motors are available in 40 mm diameter and in two lengths, namely 26 mm (50 Watt) and 36 mm (70 Watt).  The modular system with gearhead encoders and controllers from the maxon delivery program offers a large number of possible combinations.
EC-i motors are ideally suited for applications that require maximum drive in a minimum space. Typical areas of application are:
  • robotics
  • industrial automation
  • security technology

More information on the EC-i  motors from maxon motor can be viewed at-

For more information, please contact:


Warren Osak
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699

Tags:  Maxon Motor AG, maxon motor,  Electromate, BLDC Motor, Servo Motor, EC-I Motor, Brushless Motor, Brushless DC Motor, DC Motor

Step Motor Frequently Asked Questions

Q. How hot can we run a step motor without damaging it?

A. The temperature range of our motors is -20 degrees C to +150 degrees C.

Q. Can I get a step resolution smaller than 1.8″?

A. All of our motors are a standard 1.8″ in full-stepping. You can change the size of the step by purchasing drives that either have half-stepping or microstepping capabilities.

Q. How does a step motor work?

A. A step motor has two primary pieces, the rotor and stator. The stator is made out of coils of wire called the windings and the housing. The rotor is a magnet with teeth which rotates on bearings inside the stator. When current is passed through the stator windings, it produces a magnetic force that holds the rotor in a locked position, the amount of torque needed to exceed this force is called the holding torque. As current is switched in the windings, the motor takes “steps” or small movements in one direction. This movement is similar to the second hand on a clock. The amount of rotational movement per step depends on the construction of the motor. If you increase the frequency of the steps you will eventually go from a stepping movement to continuous rotation.

Q. What is the difference between series and parallel connection on an eight lead step motor?

A. On eight lead motors, you have four independent windings with two leads coming out of the motor. Each winding is paired with another. When you connect the pairs to the motor, you are literally connecting them in series or parallel. Depending on how you connect your motor the electrical characteristics change. It is important to know how these characteristics change or else you could damage the motor.

Q. What is stepper motor resonance?

A. Resonance is an unstable condition when running a step motor. Resonance usually occurs between 2-4 rev/sec and can be alleviated in most situations by putting a load on the motor, changing from full stepping to half or microstepping, or increasing your acceleration through the resonance zone.

Q. How does my power supply affect the top speed of my motor?

A. Each motor when turning acts as a generator, pumping voltage back into the drive. This is called the Electromotive Force, or back EMF voltage. The amount of EMF generated increases proportionately with the speed and inductance of the motor. Theoretically, when the back EMF equals the voltage into the drive, the motor stalls. Knowing this information, we can see that if we increase the voltage of the power supply, we are able to reach higher speeds.

Q. I need to either have my stepper drive or motor a far distance from my controller. What distance can I have between the two?

A. The distance from the drive to the motor can be up to 50 feet with the standard cable. If you need further distance you can use a shielded, low inductance cable that is larger gauge (ie. a motor with AWG 24 gauge wire should have an AWG 20 gauge cable). With our step and direction drives, you can have 50 feet between the source of the pulses and our drive, using a shielded cable. If you are communicating via serial RS232 to a computer, most stepper drives can be up to 25 feet from the computer.

Q. How many motors can I run with one drive?

A. Our drives are designed to run one motor. However, you can run more than one motor on a drive, but we suggest series connecting the motor windings to one another (which will limit your top speed). If connecting two motors to one drive, you do so at your own risk.

Q. How do I choose a step motor?

A. In our catalogs are various torque vs. speed curves. When you know the torque required and your top motor speed (rev/sec), look at these curves to determine which motor will work for you. We recommend doubling (100% safety factor) your required torque at a given speed and then selecting a motor/drive/power supply combination that can deliver that torque (i.e. If you need 100 oz-in to the system, get a motor that produces 200 oz-in at that speed).

Q. What is a reasonable inertia ratio between a motor and load?

A. This depends on the acceleration that you expect out of a system. With stepper motors, it is best to target a 1:1 inertial load to motor ratio to expect good acceleration. For servo motors, target for a 5:1 mismatch. Note: gearheads are a good option to reduce the ratio mismatch because the gearhead reduces the reflected inertia by the square of the gear ratio.

Q. Which stepper drive should I choose?

A. The easiest way to choose a motor is to look at our torque vs. speed curves in our catalog and see what type of drive was used with a particular motor. Another method is to find the output power of the motor shaft where: P = T*W/22.5 P is Power in Watts T is the torque in oz-in W is the rotational speed in rev/sec. Take this number and double it. The resulting power will allow you to adequately size the drive for the application. The other thing that you need to consider is how you want to control the motor and how you are powering the drive. The three types of controls with our drives are the internal oscillator, external step and direction, and intelligent drives/controllers. These also come with and without internal power supplies, so depending on your application, choose the drive that is best for you.

Q. Which power supply should I choose for my servo amplifier or stepper driver?

A. The two types of power supplies are regulated and unregulated. We prefer unregulated power supplies since the current doesn’t “fold back” when it gets too high. However, an unregulated power supply’s voltage may spike and blow the drive if you do not size the power supply’s voltage a little lower than the drive’s input voltage. The current on your power supply can be greater than the drive’s, but it should not be less than the rated current of the motor. Otherwise you will sacrifice the performance of your motor.

Q. What does angular velocity mean?

A. It is the RPM the lead screw of a step motor linear actuator must turn at to achieve the desired traverse speed.  RPM= Linear Traverse (inches per minute) divided by Lead (in inches)

Q. Why does my step motor shaft fail to turn?

A. No power to drive – check if AC voltage is present by checking if the green LED indicator on the drive is illuminated. Open motor windings – check that each motor winding phase has the appropriate resistance with no open coils. No incoming pulse – check for proper level and width of pulse at Logic pin No power logic – check to see that Logic Pin (ENABLE/NO POWER) is “High” or open. Low power logic – check to see that Logic Pin (HI/LO POWER) is “High” or open. Fixed load – check to see that driven load is not jammed or too large a load for the chosen motor size.

Q. Why is my step motor motion erratic?

A. Improper lead connections – confirm that the leads of the motor are connected with the proper sequence. Winding continuity – check to see that each phase of the motor has the appropriate resistance with not shorts between windings or to the housing. Incoming pulse integrity – confirm that the pulses being supplied to the driver are the proper level and width and that the rates are not too fast for the motor to maintain synchronism. Resonant instability – confirm that the motor is not operating in a resonance range by adjusting the pulse rate. Current profile adjustment – confirm that the dip switches are set for selected motor. If the problem of rough microstepping persists then the following procedure is recommended. Adjust the pulse rate to achieve a shaft speed of one revolution per second, next adjust the dc-offset to fine tune the drive to the selected motor.

Q. Why does my step motor run very hot?

A. Normal operating mode – it is normal for step motors, when run at their rated current, to be hot to the touch when operating. In general, if the motor case temperature is less that 85 degree C., there is no cause for concern. Current set too high – check to see that the current is set at the appropriate level for the motor being operated.

Q. Why does my step motor fail during acceleration or while running?

A. Improper acceleration rate – check that the increasing rate of pulses feed to the drive is not too fast for the motor to maintain synchronism with the driven load. Improper current setting – step motors require maximum current draw during acceleration. Be sure to match your motor current requirement to that of the driver. Erratic loading – if the driven load dramatically changes while motor is driving, it could overcome the speed/torque capability of system – try to run the motor with the load disconnected. No power logic – be sure that Logic Pin (ENABLE/NO POWER) is “High”

Q. Is it safe to use a DC power supply voltage higher than the voltage rating specified for the motor?

A. a. Normally this not a problem as long as the motor operates within the speed and current limits set by the manufacturer. Since motor speed is proportional to the voltage across the motor leads, select a power supply voltage that could not cause a mechanical over-speed in the event of an amplifier malfunction or a runaway condition. Furthermore, always ensure the motor meets the minimum load inductance requirements of the amplifier and make sure the current limit is set to less than or equal to the rating of the motor.

Q. How do I select the proper power supply rating for my application?

A. a. It is recommended to select a power supply voltage that is about 10 to 50% higher than the maximum required voltage for the application. This percentage is to account for the variances in Kt, Ke, and losses in the system external to the amplifier. b. The current rating of the amplifier should be high enough to deliver enough power for the application. Remember that the equivalent output voltage of the amplifier is not the same as the supply voltage, therefore the amplifier output current will not be the same as the current from the power supply. To determine thte appropriate current rating for the power supply, calculate total power required by the application and add 5%. Divide this power requirement by the supply voltage (I=P/V) to find the required current.

Q. Why do step motors run hot?

A. Two reasons here, first full current flows through the motor windings at standstill, secondly PWM drive designs lend to make the motor run hotter. Motor construction, such as lamination material and riveted rotors, will also affect heating.

Q. What is the safe operating temperature of a common stepper motor?

A. Most stepper motors have class B insulation which is rated at 130 degrees C. Motor case temperatures of 90 degrees C will not cause thermal breakdowns. Motors should be mounted where operators cannot come into contact with the motor case.

Q. What can be done to reduce motor heating?

A. Many drives feature a “reduce current at standstill” command or jumper. This reduces current when the motor is at rest without position loss.

Q. Will motor accuracy increase proportionately with higher step resolutions?

A. No, since the basic absolute accuracy and hysteresis of the motor remains unchanged.

Q. Can I use a small motor on a large load if the torque requirement is low?

A. Yes, however, if the load inertia is more than ten times the rotor inertia, cogging and extended ringing at the end of the move will be experienced.

Q. How can end of move “ringing” be reduced?

A. Friction in the system will help dampen this oscillation. Acceleration/deceleration rates could be increased. If start/stop velocities are used, lowering, or eliminating them will help.

Q. Why does the step motor stall during no load testing?

A. The motor needs inertia roughly equal to its own inertia to accelerate properly. Any resonance’s developed in the motor are at their worst in a no load condition.

Q. Why is motor sizing important, why not just go with a larger motor?

A. If the motor’s rotor inertia is the majority of the load, any resonances may become more pronounced. Also, productivity would suffer as excessive time would be required to accelerate the larger rotor inertia. Smaller may be better.

Q. What are the options for eliminating resonance?

A. This would most likely happen with full step systems. Adding inertia would lower the resonant frequency. Friction would tend to dampen the modulation. Start/stop velocities higher than the resonant point could be used. Changing to half step operation would greatly help. Ministepping and microstepping also greatly minimize any resonant vibrations.

Q. Why does the step motor jump at times when it is turned off?

A. This is due to the rotor having 50 teeth and therefore 50 natural detent positions. Movement can then be +/- 3.6 degrees, either direction.

Q. Do the rotor and stator teeth actually mesh in a step motor?

A. No. While some designs use this type of harmonic drive, in this case, an air gap is very carefully maintained between the rotor and the stator.

Q. Does the motor itself change if a microstepping drive is used?

A. The motor is still the standard 1.8 degree stepper. Microstepping is accomplished by proportioning currents in the drive. Higher resolutions result.

Q. A move is made in one direction, and then the step motor is commanded to move the same distance but in the opposite direction. The move ends up short, why?

A. Two factors could be influencing the results. First, the step motor does have magnetic hysteresis which is seen on direction changes. This is in the area of 0.03 degrees. Any mechanical backlash in the system to which the motor is coupled could also cause loss of motion.

Q. Why are most step motors constructed as eight lead motors?

A. This allows greater flexibility. This type of step motor can be run as a six leaded motor with unipolar drives or as an eight leaded motor with bipolar drives connected in either series or parallel.

Q. What advantage do series or parallel connection windings give?

A. With the windings connected in series, low speed torque’s are maximized, but this also produces the most inductance so performance at higher speeds is lower than if the windings were connected in parallel.

Q. Can a flat be machined on the motor shaft?

A. Yes, but the motor must be disassembled so the flat can be machined on the shaft. Care must be taken to not damage the bearings, the stator windings, and the rotor during disassembly.

Q. How long can the motor leads be?

A. For bipolar drives, 100 feet. Unipolar designs, 50 feet. Shielded, twisted pair cables are required.

Q. Can specialty motors; explosion proof, radiation proof, high temperature, low temperature, vacuum rated, or waterproof be provided?

A. Yes. Specialty servo or stepper motors are available for a variety of harsh environments. Contact us for more details.

For more information, please contact:


Warren Osak
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699

Tags:  Step Motor, DC Step Motor, Stepper Motor, BLDC Motor, Automation, Motion Control, FAQ

DC Servo Motor Sizing Made Easy: A Practical 1/2 Day Course presented by Dr. Urs Kafader, maxon motor ag

Monday February 3rd in Coquitlam, BC  and  Tuesday February 4th in Calgary, AB

This half-day seminar provides the practical information you need to successfully select the right DC motor — be it brushed or brushless — for your application.  You’ll learn about the interpretation of motor data and how you can use this information for motor sizing.  Whether you need high speed and dynamics or just high torque, this seminar will teach you to size a motor + drive with just the right power reserves, avoiding costly oversized motors.  The Calgary seminar features a discussion on the selection and operation of extreme environment servo motors including downhole drilling motors.

Presenter: Dr. Urs Kafader, maxon motor ag, author of the “Selection of High-Precision Microdrives”

What You’ll Receive:

  • maxon Formulae Handbook
  • E-Learning software tutorial on USB Stick
  • maxon Catalog 

What You’ll Learn:

  • Basics of DC motor data. Learn how to interpret motor data sheets and use the speed-torque line information for optimum motor sizing.
  • Systematic drive selection in the context of your application specific requirements and boundary conditions. This includes optimum power management, control loops, accuracy and ambient conditions.
  • Basics of gearhead data and their impact on motor selection.
  • Selection criteria for DC motors. Topics include the characteristics of different commutation types for brushed and brushless DC motors and when to use them.
  • Application examples. Learn how to extract the key parameters for drive selection from your application: The examples include continuous operation as well as dynamic operation cycles.
  • Motion Control: The main features and application possibilities of maxon EPOS and ESCON controllers [Coquitlam Seminar Only]
  • Sizing of DC Servo Motors for Extreme Environment Operation [Calgary Seminar Only]

How to make a motor “Heavy Duty” and how do key motor data change with ambient temperature and environment they run in [Calgary Seminar Only]


BEST WESTERN PLUS Coquitlam Inn Convention Centre
Coquitlam, BC
Monday February 3, 2014
Phone: (604) 937-1345
Directions to the Best Western Plus Coquitlam Inn can be viewed at the following link: Best Western Plus Coquitlam Inn Directions


Holiday Inn Express Airport Calgary
Tuesday February 4, 2014
Phone: (403) 769-1888
Directions to the Holiday Inn Express can be viewed at the following link: Holiday Inn Express Airport Calgary Directions

9:30 am – 2:30 pm. Lunch included

$59 CDN/person + GST

To Register: The Seminar requires pre-registration & payment by Credit Card or PayPal. Click on the link below to be directed to our Online Payment Registration Form.

Maxon Seminar Registration Online Link

OR call Electromate at 877-737-8698 with your credit card information.

download: Calgary Seminar Agenda.pdf
download: Coquitlam Seminar Agenda.pdf

Tags:  maxon, maxon motor, Dr. Urs Kafader, DC Motor, Servo Motor, Automation, Motion Control, Motor Seminar, Heavy Duty Motor, Downhole Motor, Drilling Motor, Seminar

Live Webinar: Extreme Environment Operation of DC Servo Motors

Join us for a Live Webinar presented by maxon motors on January 21, 2014

Space is limited. Reserve your Webinar seat now.

Register now to watch this webinar live or anytime after January 21, 2014.

This webinar will include a general discussion on DC Servo (brush and brushless) Motor Technology and the benefits of using maxon’s EC HD (electronically commutated heavy duty) motors in extreme environment applications, including a brief introduction to maxon’s EC HD motor & gearbox family. A technical discussion will follow on the operation, construction and modification of EC HD motors and gearboxes for extreme environments such as: vacuum, downhole, high temperature, submersible, space rated, high shock/vibration, low temperature, etc.), including the following discussion topics:

  • EC HD operation in air vs. in oil
  • How extreme temperature operation affects motor performance
  • Why the maxon winding is critical in battery powered applications and how this benefits MWD (Measurement While Drilling) tool service life
  • Consideration of IR losses (IR drop) when running EC HD motor cables up to 5000 meters
  • Suitability of the EC HD motor for backdriveability
  • Using the EC HD motor as a generator in downhole applications
  • Spindle applications using the EC HD motor platform
  • EC HD operation in ultra-high vacuum: Outgassing, Heating and Performance Derating considerations?

Title: Extreme Environment Operation of DC Servo Motors
Date: Tuesday, January 21, 2014
Time: 11:00 AM – 12:00 PM EST
Presenters: Dr. Urs Kafader & Dr. Robin Phillips, maxon motor AG

After registering you will receive a confirmation email containing information about joining the Webinar.

Customized IP66 Motor and Gearmotor Solutions

Groschopp Product Family

Groschopp Product Family

Groschopp’s expertise in designing and manufacturing motors and gearmotors to IP66 standards has been honed on over a decade of experience with many  rigorous test specifications from Tier 1 companies.  These rigorous test specifications have included high vibration, salt spray, mud, temperature extremes, and “million-mile” operating guarantees.  Application experience and a broad product portfolio allow OEMs working with Groschopp to quickly and reliably achieve exceptional, cost-effective designs.  Typical applications include:

  • Pulp and Paper Processing
  • Fluid Pumps
  • Wastewater Treatment
  • Food Processing Equipment
  • Heavy Duty and Off-Road Automotive
  • Liquid Mixers and Processors
  • Commercial Grade Construction Tools
  • Chemical Processing

“Very few manufacturers in our industry achieve the level that we have gone to develop this product line – they stop at IP65,” comments Ed Tullar, Sales Manager.  “This new product line captures our many years of engineering experience that has been tested and proven with a wide variety OEMs, and it packages that experience into these optimum harsh environment solutions.”

The Groschopp product line includes Permanent Magnet DC, Brushless DC, and AC Induction motors ranging from 0.05 hp to 1.0 hp. Any of the motors can be coupled with Right Angle, Parallel Shaft or Planetary speed reducers to create an integrated, IP66-rated gearmotor solution.

For complete product specifications, application examples and details on testing and protection features get an in-depth look into IP ratings.

Information on Groschopp’s family of PMDC motors and gearmotors can be viewed at the link below-

For more information, please contact:


Warren Osak
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699

Tags:  Groschopp, Electromate, IP66, PMDC, PMDC Motor, AC Motor, DC Motor, AC Gearmotor, DC Gearmotor

NEW configurable DC motors and gearheads

maxon motor’s  DCX series is being expanded with two new DC motors.  The GPX 22 gearhead is now also available in a version with reduced noise level and with ceramic axes.

In addition to the maxon DCX 10L, a shorter version is now also available, the DCX 10S.  Like all motors in the DCX series, this brushed DC motor excels through high power density and low vibration.  The DCX 10S exceeds the 1 mNm threshold during continuous use.  With its mechanical output power of up to 1.4 W in a 10 mm diameter, it is a real powerhouse.  Regardless of whether this electric motor is equipped with sintered bearings or ball bearings, the DCX 10S features extremely quiet operation running below 35 dBA*.

Maxon's NEW DCX configurable DC motors and gearheads

Maxon’s NEW DCX configurable DC motors and gearheads

The DCX 22L is the new longer version of the DCX 22S.  This brushed DC motor, with a diameter of 22 mm, even outperforms the existing maxon RE 25.  With the DCX 22L the same power is achieved, yet with 30% less volume and weight.  The GPX gearhead series is also being expanded with two new variants:

The GPX 22C is an optimized version of the GPX 22.  The improved performance data and life span were achieved by using ceramic axes.  Although the same in size, it provides approximately 20% higher torques. Another new member in the maxon GPX family is the low-noise version of the GPX 22.  The GPX 22LN has special plastic planet gears in the input stage that reduce operating noise, which mainly occurs in the input stage, by about 5 dBA*.

Ready in 11 days. All configurable DC motors, gearheads and sensors of the maxon DCX program can be ordered online.  After only 11 working days, the drive systems are ready to be shipped from Switzerland. Detailed product data can be viewed online immediately, and 3D data for the configuration is available for downloading.  Discover more at

*Measured in accordance with maxon standards, see maxon Catalog 2013/14, page 6.


Warren Osak
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699

Tags:  maxon, DCX, Electromate,  brush motor, dc brushed motor, dc motor, gear, gearhead, gearheads, motion control, motors, motors & motion control, electric motor

What is different about direct drive motors?

Some slight differences in their magnetic design.

There are several factors that define the type of motion or motor that is best for an application.  Directly driving a shaft is not new technology.  Moving slow, smooth and accurate while positioning in fine increments takes the right combination of technology.  The selection of a motor, encoder, bearing system, and motor controller all contribute to the end result.

Kollmorgen Cartridge DDR Motor Family

Kollmorgen Cartridge DDR Motor Family

Motors that are designed for direct drive applications tend to be optimized for lower mechanical speeds.  This is done by increasing the magnetic pole count so that the electrical frequency remains at a level for good control and efficiency while the mechanical speed of the motor is slower.  It is not uncommon to see 16, 24, 36, even 60 poles (magnets) in a motor.  A higher pole count also reduces the iron cross section required and also allows for larger through-holes (very common on direct drive motors).  Direct drive motors with large through-holes allow you to run optics, cables, and other items through the center of the motor.

Other advantages to this high pole count configuration is slightly higher torque output for a given diameter, approximately 20-30% increase.  Historically high pole count has meant reduced speed output, but recently advanced processors are allowing higher encoder frequencies.  It is not uncommon to see a direct drive motor operating at 2000-3000 rpm with the right set of bearings and the proper motor controller.  Direct drive motors tend to be shorter in axial length than diameter, this is a design choice rather then an attribute of the motor.

For more information on Electromate’s family of direct drive rotary motors, please contact:


Warren Osak
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699

Tags:  Servo Motor, Direct Drive Motor, Electromate, magnetic pole count, Brushless Motor, Electric Motor, DC Motor

Join maxon for a Webinar on September 10, 2013

Join maxon motor for a webinar on September 10, 2013 from 11:00 AM – 12:00 PM Eastern Standard Time.

Topic: A New Way to Customize, Configure, and Order Compact Drive Systems
Presented by: Matt Badger, e-Business Agent for maxon precision motors, inc.
To Register please visit:

Do you need a precise and powerful microdrive — one that is customized for a specific application and ready for shipment in 11 working days or less?  This step-by-step presentation describes how to configure and combine DC motors with gearheads and sensors — quickly, easily, and according to your exact requirements.

In this presentation from maxon motor, attendees will discover a simple, on-line procedure for configuring a high-precision microdrive system ideal for almost any application, from aerospace to medical to robotics.  Key to this capability is the company’s DCX motor line.  Known for high power density, a patented ironless rotor, and quiet operation, maxon DCX motors ensure a highly dynamic drive in almost any situation.  Learn why these motors, combined with compact maxon GPX gearheads, maxon ENX encoders, and intelligent control electronics, form the basis for a custom-made microdrive solution.  In addition, participants will understand why microdrive customization no longer means extended lead times.  Once configured online and ordered, a custom DCX drive system is ready for shipment in 11 working days or less.

Key Take-aways:

  • Understand key specifications of maxon DCX motors, GPX gearheads, and ENX sensors
  • Learn how to configure your motor, gear, and encoder combination in a few simple steps
  • Learn how to add intelligent control electronics
  • Discover how to get your customized order processed in 11 working days or less

We look forward to seeing you on September 10th!!

Custom High Torque Gear Motors from Applimotion

Applimotion low-profile frameless motor

Applimotion low-profile frameless motor

Loomis, Cal. – Applimotion has introduced custom gear motors for high torque, low speed and low profile applications. The assemblies combine precision gearing and direct drive frameless motor kits to form a new high torque alternative to coupling a servo motor to a traditional gear box.

Applimotion combines its ULT, UTH, and UTS low-profile frameless motors with the right gearing solution. Combining direct drive motor technology with the appropriate gearing solution may be the best alternative for smoothness, low speed, high torque and low profile package. These assemblies include precision bearings and high-resolution encoders, and the can run with any traditional servo controller.

Applimotion can create custom gear motor assemblies ranging in size from 25 mm to 800 mm diameter. If you don’t have the time or experience designing custom motor assemblies, and you have a unique application, Applimotion can turnkey the project for you. Design engineers are experienced and available to talk about your needs and quickly work to a solution.

For more information, visit .

Warren Osak
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699

Tags:  Applimotion, BLDC Motor, Brushless DC Motor, brushless dc motors, Brushless Motor, DC Motor, Direct Drive Motor, Electric Motor, Electromate, Frameless Motor, Motion Control, Servo Motor

The importance of the Speed-Torque Gradient in DC Motor Sizing

Often overlooked when sizing DC motors is the Speed-Torque Gradient.

The Speed-Torque Gradeint is defined as  Δn / ΔM  [rpm/mNm] .

The speed / torque gradient is an indicator of a motor’s performance.  The smaller the value, the more powerful the motor and consequently the less motor speed varies with load variations.  It is based on the quotient of ideal no-load speed and ideal stall torque.

The speed torque-gradient can be considered a measure of the motor strength, which is defined by motor type and size and not the winding selected.  Basically it’s how much speed drop the motor will have for each 1mNm of torque applied.

In the figure below, enhancing the load torque leads to a linear reduction of the speed.  Thus it becomes clear what the meaning of Δn/ΔM is:  It’s the gradient of the speed-torque line.

Speed Torque Gradient Curve for Maxon Motors

For more information, please contact:

Warren Osak
Toll Free Phone:   877-737-8698
Toll Free Fax:       877-737-8699

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