FAQ

When selecting a servo motor, you should consider the following factors:

Torque requirements: How much force or torque do you need to move your load? Torque is usually specified in Newton-meters (Nm) or ounce-inches (oz-in).

Speed requirements: How fast do you need the motor to move? Speed is typically measured in revolutions per minute (RPM).

Power supply: Make sure the servo motor is compatible with the available power supply, whether it's AC or DC.

Load characteristics: What is the load you need to move? Consider the size, weight, and the inertia of the load.

Control method: Do you need open-loop or closed-loop control? A closed-loop system uses feedback to maintain precise control, while open-loop systems rely on pre-set input commands.

To calculate the required torque, you need to know the force needed to move the load, as well as the distance from the motor’s axis to the center of the load (lever arm). The formula for torque is:

Torque (Nm)
=
Force (N)
×
Distance (m)
Torque (Nm)=Force (N)×Distance (m)

You can also consult the datasheet of the equipment you’re controlling for recommended torque values.

Brushed Servo Motors: These are simpler, more cost-effective motors with brushes that provide electrical contact with the rotor. They are typically used in less demanding applications.

Brushless Servo Motors: These motors are more efficient, have a longer lifespan (since they lack brushes), and provide smoother performance. They are ideal for applications requiring high precision and durability.

To determine the speed, consider how fast your application needs to move. For example:

CNC machines or robots might require high-speed movements for quick actions.

Positioning systems might need slower, more controlled movements.

You can calculate the RPM (revolutions per minute) needed based on how much distance your load needs to cover and how quickly it needs to reach the desired position.

Servo motors typically operate on DC (direct current) or AC (alternating current) power. You need to match the power supply to the motor's specifications:

DC servo motors generally require a DC power supply, and the voltage and current must match the motor’s rated values.

AC servo motors typically require an AC power supply, and may require additional components like an inverter for speed control.

Continuous torque refers to the amount of torque the motor can produce consistently over time without overheating.

Peak torque refers to the maximum torque the motor can produce for a short period, typically during acceleration or under heavy load conditions.

For most applications, you’ll need a motor that can provide adequate continuous torque for normal operation, while the peak torque should be considered for sudden load changes.

Both stepper motors and servo motors are used for precise positioning, but they have different characteristics:

Stepper motors are good for low-cost applications with simple control systems. They provide precise steps in rotation but can be less efficient and prone to overheating at higher speeds or loads.

Servo motors are more suitable for high-performance applications requiring high speed, torque, and efficiency. They use a feedback system to maintain precise position control.

Choose a stepper motor for low-load, low-speed, and cost-sensitive applications, and a servo motor for higher precision and performance requirements.

Make sure the servo motor’s signal input type (analog, digital, PWM, etc.) matches the output of your controller. Additionally, check if the controller can handle the motor’s power ratings, voltage, and feedback signals. If using a closed-loop system, ensure the controller supports the feedback mechanism (like an encoder or resolver) the motor uses.

AC Servo Motors: Used in industrial machines, robotics, and automation systems where high performance and speed are required.

DC Servo Motors: Suitable for low-cost applications where precise control and simple speed regulation are needed.

Linear Servo Motors: Used for direct linear motion control in applications like actuators and automated machinery.

Rotary Servo Motors: Most common and used in robotics, CNC, and conveyor systems for rotational motion control.

If you’re unsure about which motor is best for your application, consider the following:

Consult an expert: Contact motor manufacturers or distributors for recommendations based on your specific needs.

Test different motors: If possible, try out different motors in your setup to see which one meets your performance requirements.

Use simulation tools: Some manufacturers offer online tools to simulate your motor selection before making a purchase.

Proper maintenance includes:

Regular cleaning to avoid dirt buildup on the motor and encoder.

Monitoring temperature and load to avoid overheating.

Periodic inspection of electrical connections and feedback components.

Lubrication (if required) for motors with moving parts.

Always refer to the manufacturer's manual for specific maintenance guidelines.