The world's smallest direct drive motor

Servo motors featuring fast acceleration and Precise positioning, specially designed
for gearless use

Fast acceleration and precise positioning, features
that only a manufacturer specializing in rotary encoders can offer.
Experience the high-performance hollow micro direct drive motor.

Product List


All μDD motors have a space-saving (compact) design and are capable of high-torque and high-accuracy positioning.

  • MDS13

    The world's smallest direct drive motor.
    It is ideal for a gripper and robot hands for lightweight working such as electronic components.

    • Body diameter: φ13 mm
    • Body length: 25.4/31.4/37.4mm
    • Max torque: 7/15/25mN/m
    • Max speed: 3000rpm
    • Max resolution:11bit

    Product Inquiry

  • MD20

    The world's smallest servo motor of all hollow-shaft type.
    It is ideal for end effectors (hand, gripper, Zθ unit) and also small robot hands with a combination of low reduction ratio gears.

    • Body diameter:φ21mm
    • Body length:31.5/37.5/43.5mm
    • Max torque:40/80/120mN・m
    • Max speed:3,000rpm
    • Max resolution:288,000P/R、18bit
    • Hollow Diameter:φ2.6mm(MDH type)

    Product Inquiry

  • MD30

    It is ideal for high-precision dispenser and small gimbal drive.

    • Body diameter:φ30mm
    • Body lengyh:31.5/37.5/43.5mm
    • Max torque:140/280/420mN・m
    • Max torque:1,000rpm
    • Max speed:432,000P/R、19bit
    • Hollow diameder:φ4mm(MDH type)

    Product Inquiry

  • MDH(12)-40

    Inner diameter enlargement type of MDH-40 series .
    Cables, lasers, etc. can be placed on the inner diameter of φ12 mm.

    • Body diameter:φ40mm
    • Body length:31.5/37.5/43.5mm
    • Max torque:0.33/0.70/1.0N・m
    • Max speed:450rpm
    • Max resolution:1,296,000P/R(after 4 multipliers )
    • Hollow shaft:φ12mm

    Product Inquiry

  • MDH-60

    Small sized large diameter hollow shaft.
    It is ideal for end effectors, robot joints, etc.

    • Body diameter:φ60mm
    • Body length:31.5/37.5/43.5mm
    • Max torque:1.1/2.1/2.7N・m
    • Max speed:300rpm
    • Max resolution:2,000,000P/R、21bit
    • Hollow shaft:φ20mm

    Product Inquiry

  • MDH-70

    Small sized large diameter hollow shaft. It is ideal for Index table, rotary actuator replacements and robots (elbow and shoulder equivalents).

    • Body diameter:φ70mm
    • Body length:31.5/37.5/43.5mm
    • Max torque:1.0/2.2/3.1N・m
    • Max speed:200rpm
    • Max resolution:2,592,000P/R(after 4 multipliers)、21bit
    • Hollow shaft:φ25mm

    Product Inquiry

  • MC-200

    A small servo driver that Maximizes the performance of μDD motor.

    Product Inquiry

  • MC-200C

    Ultra-small but high output up to 18Arms(25A)

    Product Inquiry

  • Peripherals

    Extension cable
    Cable for connection to host device

    Product Inquiry


Advantages of ΜDDmotor


This product has features that only a manufacturer specializing in rotary encoders can offer.
We have achieved a compact, hollow design while retaining the advantages of a conventional DD motor.

High torque
Compared to conventional AC servo motors about 5 times higher torque dencity.
Ultra small size
Compared to conventional
DD motors
as small as 13mm
Hollow shaft
Top-class servo motor in the industry
Hollow ratio of 35(%)

Strengths demonstrated in the mounting and assembly. 

  • Lightweight
    Contributes to higher drive speed and lower load on the equipment.
  • High-precision encoders
    High-precision encoders make it possible to manufacture robots with high positioning accuracy.

Strengths in Semiconductor and LCD Manufacturing Equipment

  • High accuracy
    High positioning accuracy enables alignment.
  • No backlash
    Gearless structure eliminates positioning errors caused by backlash.
  • High rigidity
    High rigidity bearings are used to directly receive the load.

Strengths demonstrated in robotic applications

  • High back-drivability
    High back-drivability enables tactile feedback and a new grasping strategy of grasping an object while pressing it new grasping strategy.
  • No backlash
    The motor current and encoder value can be detected with high accuracy.

What is hollow shaft motor? 


Hollow shaft motor

A hollow motor is a motor with a through-hole in the center of the motor, which improves design flexibility.
For example, cables, air tubes, lasers, etc. can pass through the hollow.
For example, cables, air tubes, lasers, etc. can be penetrated in the hollow, making it possible to save space and increase the precision of the equipment.


Complete support system


Three ways we provide support for our uDD motors

Selection Support

Click here for motor and drive selection, or contact us for assistance.


Tuning & Support

Manual tuning allows you to further optimize the settings.

Paid tuning by MTL engineers is also available.
you can use the driver you are using now.


After-Sales Support

We provide rigorous product testing and adhere to a strict quality assurance system.

If you need technical support or have any questions about this product, contact us.

Collaborative products with other companies

Can be connected to Mitsubishi Electric and Panasonic drivers.
A conversion connector and compatibility chart are available.
Please download from the link on the right.

 Conversion connector   compatibility chart


Please feel free to contact us first.

μDDmotor Case study



the following are the advantage and merites of μdd motors product.
this presentation will show the usefulness of the µdd motor in a robot hand that utilizes high back-drivability and
bilateral control.
in addition, the small size and high torque of the motor helps to increase the precision and speed of equipment and
reduce vibration noise.
there is only a part of what we can show, but there are many other applications.
please contact us for more information.

(1) Mounting machines such as chip mounters

Air tubes, lasers and other materials can thread through the hollow shaft, utilizing less space.

Characteristics: High torque, ultra-compact, hollow shaft, light weight

  • high torque

  • ultra small

  • hollow shaft

  • light weight


(2)Image inspection equipment stage.

Although ultra-compact, it has the high precision, responsiveness, and rigidity of a DD motor.
The deceleration mechanism, which used to be essential for small motors, is now a direct drive.
This allows for a simple structure.

Characteristics: High torque, high accuracy, no backlash (high response), high rigidity

  • high torque

  • high percision

  • no backlash

  • high rigidity


  (3) GP-Arm, a twin-armed robot that transmits physical sensations

The robot can share force, tactile and visual information in real time, even with the operator at a distance. You can also teach the robot where you are positioned, as well as a visualization, including active gimbal tracking at higher speeds.

Characteristics: High torque, ultra-compact,holloe dlameter, high backdorivability

  • high torque

  • ultra small

  • hollow shaft

  • high backdrivability


Please feel free to contact us first.

Detail of introduction


Contact an agent

Once you have made an inquiry, you will be assigned a customer service representative. They will help you select the most suitable motor and driver for your equipment and answer your questions in an easy-to-understand manner.
We will reply by the next business day.

Order and delivery

After the specifications are decided, the order is placed with the distributor. It takes about 5 to 6 weeks from the time you place the order for delivery.

Frequently asked questions about μDD motors


I'm having trouble selecting a motor. How do I select a motor?

We have a motor selection tool.

 Please prepare the motor load. (Weight of the material to be conveyed, conveyance speed, cycles, etc.)

 How can I purchase the product?

We have agents, please contact them below.

Please advise me on how to tune and select a driver (amplifier).

  1. We are working on the linkage so that you can use the driver you are using now.

    Please check the following URL for supported drivers.

  2. If you want to use a driver that is not on the list, please contact us.。

  3. In the case of our driver

    1. You can optimize the operation by manual tuning.
    2. Paid tuning by engineers is also available.

Please feel free to contact us first.

About us

We take pleasure in creating things that do not exist in the world and
enhancing the value of our customer's equipment.
Based on precision assembly technology, we develop, manufacture,
and sell ultra-compact products.

The Smallest & High Resolution

Made in Japan

We have established a production system that can provide high quality at low cost.
The specifications we provide are guaranteed values based on the safety factor. Parts are also procured in Japan to ensure a stable supply.

Manufacturing system

We repeatedly check the ideal values in the design process and the feasibility of the product in the manufacturing process to ensure the quality and high functionality of our products.

Full range of after-sales services

The hardware has passed many tests and is controlled by a strict quality assurance system.
In the event of a defect, we will replace it free of charge.

About us


Campany name
Microtech Laboratory, Inc.
Establishment date
February 1, 1981
Capital Stock
45.5 million yen
President and Representative Director
Design, manufacture, and sale of microencoders (rotary encoders) and μDD motors (direct drive motors)
Settelment date
July 31
 8-1-46, Honcho Kamitsuruma, Minami-ku, Sagamihara-shi, Kanagawa
Contact adress


Main bank
Bank of Yokohama, Sagamiono Branch Mitsubishi UFJ Bank, Machida Branch Mizuho Bank, Machida Branch

Please feel free to contact us first.

Please contact us
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