Servo FAQ
How will the Speed/Torque curve change if I supply higher voltage or more current?
What wattage motors do your Brushless DC go up to?
How fast do your Brushless DC go up to?
What are the advantages of Micro stepping?
How do you control resonance in your application?
What do I need to know in order to select the right motor for my application?
What type of value added work does Shinano Kenshi Corporation provide?
How will the Speed/Torque curve change if I supply higher voltage or more current?
How come your integrated connector stepper motors are rated only at Class A for temperature?
What is your lead time for custom samples?
Will the part number change when we go into production?
What are the differences between variable reluctance stepper motors and permanent magnet stepper motors?
How does demagnetization occur?
How does the counter EMF reduce the motor torque?
At what quantities levels will you do custom products?
What is Bifilar winding?
Where do the sources of heat inside the motor come from?
What is MTTF vs. MTBF?
If I buy your integrated connector stepper motor, does it come with a wire harness?
Will the part number change when we make a custom motor?
Does Shinano Kenshi Corporation make drivers for stepper motors?
How will the Speed/Torque curve change if I supply higher voltage or more current?
Higher supply voltage will result in higher speed capabilities; more current will result in more torque. (top)
What wattage motors do your Brushless DC go up to?
From 1 watt to 150 watts. (top)
How fast do your Brushless DC go up to?
Most are variable speed with ranges from 400-3000 rpm while some models can run as high as 45,000 rpm. (top)
What are the advantages of Micro stepping?
Micro stepping serves three purposes. First, it allows a stepping motor to stop and hold a position between the full or half-step positions. Second, it largely eliminates the jerky character of low speed stepping motor operation and the noise at intermediate speeds. Third, it reduces problems with resonance.
Although some micro stepping controllers offer hundreds of intermediate positions between steps, it is worth noting that micro stepping does not generally offer great precision, both because of linearity problems and because of the effects of static friction. (top)
How do you control resonance in your application?
Use of elastometric motor mounts or elastometric couplings between motor and load can drain energy out of the resonant system, preventing energy from accumulating to the extent that it allows the motor rotor to escape from control. This can help control resonance in your application.
Also viscous damping can be used. Here, the damping will not only draw energy out of the resonant modes of the system, but it will also subtract from the total torque available at higher speeds. Magnetic eddy current damping is equivalent to viscous damping for these purposes. (top)
What do I need to know in order to select the right motor for my application?
1. Driving condition: Voltage, speed, dynamic torque/inertia, current, and duty cycle
2. Size constraint: Ambient temp and temp range, life of the motor
For steppers
1. Driving method: Constant current or constant voltage
2. Driving the motor: Unipolar or bipolar
For BLDC
1. Driving the motor: Constant speed or variable speed. (top)
What type of value added work does Shinano Kenshi Corporation provide?
We offer a large array of custom service to our customers. We offer value added services which are completely done on location and not outsourced to other vendors. We handle value added products like gears, pulleys, drive belts, connector termination, mounting plates, custom shaft configurations, custom pin out locations, alignment angle of pin out location, and much more. We can also provide custom drive electronics and for certain industries and markets, contract manufacturing capabilities. We pride ourselves on the level of customization we can offer to our customers. Please contact us to learn more. (top)
How will the Speed/Torque curve change if I supply higher voltage or more current?
Higher supply voltage will result in higher speed capabilities; more current will result in more torque. (top)
How come your integrated connector stepper motors are rated only at Class A for temperature?
The limiting factor is the PC Board which is rated for Class A. However all key internal components (windings, etc) are UL listed as Class B. Data can be provided upon request. Shinano Kenshi Corporation has the capability to supply high temperature rated motors over NEMA 17 and 23 frame sizes. (top)
What is your lead time for custom samples?
We offer competitive turn around on all our custom sample orders. However, each sample ranges in the level of customization and complexity. Therefore our lead time varies based on product and customer demands. Please contact a Regional Sale Manager for more information. (top)
Will the part number change when we go into production?
Yes, once it is approved by the customer, official approval documents will be provided and will readfile the proprietary part number. (top)
What are the differences between variable reluctance stepper motors and permanent magnet stepper motors?
You can generally tell the two apart by simply feeling them when no power is applied. Permanent magnet motors tend to "cog" as you twist the rotor with your fingers, while variable reluctance motors almost spin freely (although they may cog slightly because of residual magnetization in the rotor). You can also distinguish between the two varieties with an ohmmeter. Variable reluctance motors usually have three (sometimes four) windings, with a common return, while permanent magnet motors usually have two independent windings, with or without center taps. Center-tapped windings are used in unipolar permanent magnet motors
Stepping motors come in a wide range of angular resolution. The coarsest motors typically turn 90 degrees per step, while high resolution permanent magnet motors are commonly able to handle 1.8 or even 0.72 degrees per step. With an appropriate controller, most permanent magnet and hybrid motors can be run in half-steps, and some controllers can handle smaller fractional steps or microsteps. Hybrid motors are indistinguishable from permanent magnet motors from the controller's point of view.
For both permanent magnet and variable reluctance stepping motors, if just one winding of the motor is energized, the rotor (under no load) will snap to a fixed angle and then hold that angle until the torque exceeds the holding torque of the motor, at which point, the rotor will turn, trying to hold at each successive equilibrium point. (top)
How does demagnetization occur?
The best way to demagnetize something is to expose it to a high frequency-high amplitude magnetic field. This can be accomplished by running the control system to spin the rotor at high speed when the rotor is actually stalled, or spinning the rotor at high speed against a control system trying to hold the rotor in a fixed position. These will both expose the rotor to a high amplitude high-frequency field. If such operating conditions are common, particularly if the motor is run near the curie temperature of the permanent magnets, demagnetization is a serious risk and the field strengths (and expected torques) should be reduced accordingly! (top)
How does the counter EMF reduce the motor torque?
In a permanent magnet or hybrid stepping motor, the magnetic field of the motor rotor changes with changes in shaft angle. The result of this is that turning the motor rotor induces an AC voltage in each motor winding. This is referred to as the counter EMF because the voltage induced in each motor winding is always in phase with and counter to the ideal waveform required to turn the motor in the same direction. Both the frequency and amplitude of the counter EMF increase with rotor speed, and therefore, counter EMF contributes to the decline in torque with increased stepping rate. (top)
At what quantities levels will you do custom products?
This depends on many factors such as the complexity of custom work and the overall volume a customer might expect for a given product. Please contact your Regional Manager or Authorized Representative for more details as these vary on a case-by-case basis. (top)
What is Bifilar winding?
Bifilar windings on a stepping motor are applied to the same rotor and stator geometry as a bipolar motor, but instead of winding each coil in the stator with a single wire, two wires are wound in parallel with each other. As a result, the motor has eight wires and not four.
Where do the sources of heat inside the motor come from?
The heat given off by the motor windings is due to simple resistive losses, eddy current losses, and hysteresis losses. If this heat is not conducted away from the motor adequately, the motor windings will overheat. The simplest failure which can be created is insulation breakdown, but it can also heat a permanent magnet rotor to above its curie temperature, the temperature at which permanent magnets lose their magnetization. This is a particular risk with many modern high strength magnetic alloys. (top)
What is MTTF vs. MTBF?
MTTF is defined as “Mean Time To Failure.” The point MTTF is the total device hours divided by the number of failures. The failure rate is defined as the reciprocal of the MTTF. Where no failures occurred during testing, the point MTTF and failure rate have been calculated assuming one failure.
MTBF is defined as “Mean Time Between Failures”. It is the average time a system will operate without a failure. Failure may be the result of one or many faults. The MTBF is a commonly quoted reliability in engineering. (top)
If I buy your integrated connector stepper motor, does it come with a wire harness?
As a standard motor it does not. However, we can develop a mating wire harness to match your needs (length, end termination in your chosen connector, tubed wires, tie wrapped, etc.) (top)
Will the part number change when we make a custom motor?
Yes, part numbers change and a new one will be issued for each custom product and customer. (top)
Does Shinano Kenshi Corporation make drivers for stepper motors?
Not typically for OEM applications. We can recommend the best drive methodology based on a review of your application. (top)
