How to Select a Stepping Motor

1. Stepping Motor Selection Process

• Determine the drive mechanism
• Calculate the load torque converted to the motor shaft
• Define the motion profile and driving conditions
• Make a preliminary motor selection and calculate the acceleration torque
• Calculate the driving torque converted to the motor shaft
• Evaluate the suitability of the selected motor

Details of each step are available in our downloadable materials.Download the materials free of charge for reference.

2. Key Points in Stepping Motor Selection

When selecting a stepping motor, the points to focus on and their relative priority vary depending on the mechanical structure and driving conditions of the equipment. In general, the following points should be considered.

1. Torque Requirements

It is necessary to select a motor capable of providing the torque required to drive the load.
Load torque, acceleration torque, and friction torque should be taken into account, and the motor should be selected with an appropriate safety margin.

2. Driving Voltage and Current

A motor must be selected that is compatible with the available power supply (voltage and current).
Compatibility with the specifications of the control circuit and driver should also be confirmed.

3. Step Angle of the Stepping Motor

Select a step angle that meets the required positioning accuracy. Finer step angles enable higher-precision control.

4. Motor Size (External Dimensions)

Select an appropriate motor size while considering installation space and mechanical constraints. Dimensional standards such as NEMA standards can be used as a reference.
*Note: NEMA standards are dimensional standards for electrical products established by the National Electrical Manufacturers Association (NEMA).
SANYO DENKI also offers compact 14 mm square stepping motors and thin stepping motors that can be installed in space-constrained applications.

5. Holding Torque of the Stepping Motor

If the load must be supported while the stepping motor is stopped in an energized state, holding torque becomes an important factor.
It is necessary to select a motor that satisfies the required holding torque.

6. Environmental Conditions

Select a stepping motor that is suitable for the operating environment, including the allowable ambient temperature range and humidity range.
If dustproof or waterproof performance is required, select a stepping motor that complies with the appropriate IP rating.
SANYO DENKI also offers IP65-rated stepping motors, which can be used in equipment exposed to water, such as food-processing machinery (excluding the shaft and cable end).

7. Cost

Evaluate not only the cost of the stepping motor itself, but also the total cost of the system, including the driver and control system. A balanced trade-off between cost and performance should be considered.

8. Customization Options

If customization is required to meet specific requirements or operating environments, a manufacturer capable of flexible customization should be selected. Warranty coverage for such customization should also be confirmed.
SANYO DENKI offers a wide range of customization options, including vacuum-compatible designs, shaft modifications, and the integration of gearheads, brakes, encoders, and dampers.

3. Narrowing Down Stepping Motors Based on Selection Criteria

Once the key points are understood,stepping motors can be narrowed down based on specific criteria using SANYO DENKI’s product website. Please make use of this tool to support your motor selection. 

4. Common Issues in Stepping Motors and Example Countermeasures

1. Preventing Step Loss (Missed Steps)

Sufficient torque margin and an appropriate inertia ratio must be ensured. Since a stepping motor may lose synchronism and stop operating under overload conditions, a torque margin of approximately 1.4 to 2 times is generally recommended as a guideline.

2. Reducing Vibration and Noise

Microstepping drive enables smoother rotation, particularly at low speeds, and is effective in reducing vibration and noise.

3. Improving Torque Reduction at High Speeds

・Switch to a motor with a higher winding current (rated current)
・For DC power supply types, increase the supply voltage, or switch to an AC power supply type
・Modify the motor winding (for example, reducing the number of turns) to improve torque in the high-speed range
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5. Application-Based Case Studies of Stepping Motor Selection

• When equipment miniaturization is required: Linear stepping motors (Case study: Inspection equipment manufacturer S)
• Achieving both higher accuracy and cost reduction: Hollow-shaft motors (Case study: Semiconductor manufacturing equipment manufacturer Y)
• Reducing motor heat generation: Customized winding specifications (Case study: Medical inspection equipment manufacturer J)

SANYO DENKI supports customers’ businesses through a diverse lineup of stepping motors and a wide range of customization options tailored to customer requirements.

Release date: 2024-12-04 00:00