What to Consider When Buying Rotary Encoders

Your Guide to buying the best Rotary Encoders


A Rotary Encoder is a device used to measure the speed and direction of a rotating shaft. It can also be used as an input device for controlling the motion of machinery, such as a robot arm or a servo motor. When shopping for a Rotary Encoder, there are several factors to consider, including the type, mount, resolution, and output. This buying guide will provide an overview of the different types of Rotary Encoders available, important features to consider, and tips for getting the most out of your purchase.

Key features

  1. Type of Rotary Encoder: Consider the type of encoder you need, whether it is incremental, absolute, or both.
  2. Size: Measure the space you have available and choose an encoder that fits the designated area.
  3. Mechanical Ratings: Consider the application requirements and make sure the encoder has sufficient mechanical ratings to meet the job.
  4. Optical or Magnetic: Determine if an optical or magnetic sensor is needed for your application.
  5. Resolution: Determine the level of accuracy you need and choose an encoder with the appropriate resolution.
  6. Output Type: Determine the type of output you need from the encoder; such as pulse, serial, analog, or quadrature.
  7. Environment: Consider the environment the encoder will be used in and make sure it is rated for the environment.
  8. Communication Protocol: Determine the communication protocol you need and choose an encoder that is compatible.
  9. Cost: Determine the budget you have available for the encoder and choose one that meets the cost requirements.

See the most popular Rotary Encoders on Amazon

Important considerations


  • Durability: Rotary encoders are highly durable components that can withstand high vibration and extreme temperatures.
  • Accuracy and Precision: Rotary encoders offer accurate and precise measurements and are ideal for a wide range of applications where precise positioning is required.
  • Simple Installation: Rotary encoders are easy to install and require minimal maintenance.
  • Versatility: Rotary encoders are available in various sizes, shapes, and form factors to suit a wide range of applications.
  • Safe Operation: Rotary encoders are designed for safety with features such as overload protection, reverse polarity protection, and emergency stop capability.
  • Cost-Effective: Rotary encoders are cost-effective and provide reliable performance at an affordable price.


  • Cost: Rotary Encoders can be expensive, depending on the size and accuracy required.
  • Durability: Rotary Encoders can be prone to wear and tear, so they may need to be replaced more frequently than other components.
  • Installation: Installing a Rotary Encoder can be a complex process that requires specialized tools and knowledge.
  • Efficiency: Rotary Encoders can be less efficient than other types of components, due to their mechanical nature.
  • Accuracy: Rotary Encoders may be limited in their accuracy, depending on the model.
  • Sensitivity: Rotary Encoders can be sensitive to dust, dirt, and other environmental factors, which can affect their accuracy and performance.

Best alternatives

  1. Optical Encoders - Devices that convert angular or linear motion into an electrical signal using optical sensors.
  2. Magnetic Encoders - Devices that measure rotation or linear motion using magnetically encoded disks.
  3. Potentiometric Encoders - Devices that convert angular or linear motion into an electrical signal using a sliding contact.
  4. Hall Effect Encoders - Devices that measure rotation or linear motion using a Hall-effect sensor.
  5. Drawwire Encoders - Devices that measure linear motion using a spool of wire, a contact, and a sensor.

Related tools, supplies, and accessories

  • Cable Connectors - Devices used to physically connect rotary encoders to power supplies and other components.
  • Terminal Blocks - Slim metal blocks with screw terminals used to connect wires to circuit boards.
  • Circuit Boards - A base that houses electrical components and wiring.
  • Chassis - A metal shell that encloses the rotary encoder and its components.
  • Screws and Nuts - To hold the encoder together.
  • Shaft Couplers - Connectors used to attach a rotary encoder to a motor or other device.
  • Mounting Brackets - Attach the encoder to the desired surface.
  • Power Supply - To electrically power the encoder.

Common questions

  1. What is a Rotary Encoder? A rotary encoder is a device used to measure angular displacement, typically used as part of a control system in a variety of applications. It is also known as a rotary switch and can be used to convert data from mechanical to electrical form.
  2. What are the types of Rotary Encoders? There are two main types of rotary encoders: absolute and incremental. Absolute encoders measure the absolute angular position of the shaft, while incremental encoders measure the incremental change in the angular position of the shaft.
  3. What is the purpose of a Rotary Encoder? Rotary encoders are used to detect the angular position of a rotating shaft. They are commonly used in applications such as motor speed and position control, motion sensing, and industrial automation.
  4. What are the advantages of using a Rotary Encoder? Rotary encoders are reliable, accurate, and cost-effective. They are also easy to install and maintain, and can provide a precise measurement of angular position.
  5. What are the key features to consider when buying a Rotary Encoder? Key features to consider when buying a rotary encoder include type (absolute or incremental), resolution, maximum speed, shaft diameter, and operating temperature range.


In the early days of rotary encoders, they were used in control systems for submarines. The ability of the rotary encoder to measure an angular position of a rotating shaft was a key functionality in these systems, as it was needed to accurately measure the depth and speed of the submarine. This story highlights the versatility of rotary encoders and how they can be used in a wide variety of applications. Source

Disclaimer: This buying guide was not created by humans, and it is possible that some of it's content is inaccurate or incomplete. We do not guarantee or take any liability for the accuracy of this buying guide. Additionally, the images on this page were generated by AI and may not accurately represent the product that is being discussed. We have tried to convey useful information, but it is our subjective opinion and should not be taken as complete or factual.