Edit on GitHub




Properties Unit DYD-14-051 DYD-14-099 Note
Gear ratio - 51 99  
Rated output torque (@2,000rpm) Nm 3.7 5.4  
Permissible peak torque (accel / decel) Nm 14.8 21.6  
Permissible peak torque at E-stop Nm 43.2 43.2  
Nominal input speed rpm 2,000 2,000  
Maximum input speed rpm 8,500 8,500  
Moment of inertia x10-4 kgm2 0.119 0.135  
Backlash arcmin <3.0 <3.0  
Efficiency (@2,000rpm, 20℃) % 60 60  
Starting torque cNm 5 3  
Back-drive torque Nm 3 3  
Service life hour 7,000 7,000  
Dimensions mm Ø68 × 30 Ø68 × 30  
Weight g 400 400  

NOTE: The specification and figures in the list are subject to update for the continuous product performance improvement.


  • Please verify product’s model and number to ensure correct shipment of the product ordered.
  • Please verify all components are included in original packaging.
  • Please verify to see if there might be any damage on the product’s surface or general appearance.

(May cause injury or damage to product)

  • Do not disassemble or reassemble the product. If the product is disassembled and reassembled, the original performance cannot be guaranteed.
  • Be careful not to apply a load more than its Permissible peak torque.
  • Do not use the product when it is dropped or subjected to strong impact.
  • Please familiarize yourself with the contents of the manual before using the product. If the product is operated without correct assembly, it may cause vibration, shortened life, and/or permanent damage.
  • Use at an ambient temperature of -5° to 55° degrees Celsius.
  • Do not operate the product in an environment exposed to water, oil or explosive gas.
  • Exercise caution to the internal components are not exposed to dust and chips.
  • High quality oil seals are applied to the input/output shaft, however the product is subject to leakage. Please provide oil protection treatment as needed according to your application.
  • This product is coated with anti-rust treatment at the time of shipment, however rust may appear depending on storage and environmental conditions.
  • This product is coated with surface treatment, however rust protection is not guaranteed.
  • This product is pre-packed with lubricant, do not mix with other lubricants.
  • Please follow local government guidelines when disposing of the lubricant.


  • Avoid coming into contact with the lubricant as this may cause irritation when in contact with your skin and eyes.
  • In the case your eyes come in contact with the lubricant, wash your eyes immediately with clean water and seek medical advice.
  • In the case your skin comes into contact with the lubricant, wash your skin thoroughly with water and soap.


  • This product is covered under warranty for 1 year after purchase or up to 2,000 hours of operational time. (* Product must be used under normal operating conditions)
  • If there are any issues due to a manufacturing defect within the warranty period, we will repair or replace the product.
  • Warranty will be void if the product is used or handled improperly by user.
  • Warranty will be void if the product is repaired or modified in any way.
  • Warranty will be void if the product is damaged by any external components (ie. motor)
  • Warranty will be void in the case the product is affected by natural disasters and/or uncontrollable circumstances.
  • ROBOTIS is not responsible for any damages or injuries that may occur by the failure of the product mid operation.


The efficiency of the reducer may vary depending on the temperature of the surrounding environment and the input speed.

The efficiency curves of input speed versus output torque are as follows.


Options & Assembly Tolerance

Input shaft options

Various input shaft options can be selected with the DYD. See the following table and select the input shaft option to use with DYD.

Option Type - C Type - SD
Name Clamp-ring Set-screw (D-Cut)

Assembly Tolerance

See the dimension and the geometric tolerances of the input, output and the housing when applying DYD on the system.