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RDrive servomotor by Rozum Robotics is an all-in-one solution. RDrive servomotors unite in a single housing all the main elements: an encoder, a controller, a harmonic gear and an AC brushless motor.

About servomotor

RDrive servo by Rozum Robotics is an all-in-one robotic joint. RDrive servomotor unites in a single housing all the main elements: an encoder, a controller, a harmonic gear and an AC brushless motor. Since the controller is integrated into the robotic actuator, the RDrive is a DC servomotor with a brushless AC core.

Service life of our servo motors is 35,000 hours. Rozum Robotics also provides a 1-YEAR WARRANTY. Our online support team is eager to help you whenever needed. Detailed video instructions and technical documentation are provided. Average servomotor lead-time 2-8 weeks. A network of international dealers and distributors for local support is available.

The first RDrive servo motor was created to drive Rozum Robotics collaborative robot that we designed and built completely in house. We were disappointed with the quality of cheap Asian robotic joints and were unwilling to pay for expensive customization in Europe. The factors motivated us to take it upon ourselves to design and create our own robotic actuator.

Most robotic joints manufacturers produce a housed brushless robotic actuator coupled with an encoder. They call it a servomotor. Powered by DC current, the servomotor is controlled with the help of an external servo controller kit (sometimes called robotic servo drive or robotic actuator). In case you need a gear motor kit, you connect a gearhead to the servomotor. The overall design is whatever but not a compact servo motor in this case.

Supply Kit
  • 1x Servomotor
  • 1x STEP model
  • 1x API refrence
  • 1x User Manual
  • 1x CANopen communication guide
  • 1x Servobox (optional)
  • 1x Low voltage equipment and electromagnetic compatibility certificate

Available modifications

ModelRDrive 50RDrive 60RDrive 85
Power65 W225 W450 W
Rated torque11 Nm39 Nm108 Nm
Peak torque28 Nm54 Nm157 Nm
Rated rotational speed55 RPM55 RPM40 RPM
Diameter53 mm63 mm88 mm
Length99,5 mm101,2 mm127,1 mm
Hollow shaft diameter8 mm9 mm11 mm
Weight795 g1149 g2470 g
Voltage48 V48 V48 V
Work conditions0 °C to +35 °С0 °C to +35 °С0 °C to +35 °С
Encoder2x19 bit, magnetic, absolute position2x19 bit, magnetic, absolute position2x19 bit, magnetic, absolute position
Distributor Price:On RequestOn RequestOn Request

Servo motor components

Servo motor components

  • Encoders
    The built-in magnetic absolute encoders enable taking position measurements with accuracy of 19 bits. One of the devices monitors the angular motion of the output shaft, and the other returns feedback on positions of the rotor shaft. Feedback from the encoders indicates exact servomotor positions at a given moment and is available immediately upon powering up. No homing procedure is required because encoder readings are non-volatile. The devices are immune to temperature and humidity fluctuations, shock, vibration, and contaminants that are not ferromagnetic
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  • Controller
    The controller is the core of the RDrive closed-loop motion control system. Tailored to be compatible with other structural elements, the integrated smart chip generates PWM signals to drive brushless AC motors to deliver required motion output. The RDrive controller interfaces with other servo components (encoders, temperature transducers) to read or calculate position, speed, and torque. Based on the readings and calculations, it determines whether the motor has reached the required position and speed and, if needed, tunes the motion parameters.
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  • Harmonic gearbox
    Harmonic gearbox
    The RDrive series features integrated harmonic gearboxes that use the strain-wave gear technology. With the gear ratio of 1:100 and an almost-zero backlash, the technology delivers high-torque output without impacting precision of servos. The integration of the gear into the servo housing eliminates the need for additional couplings, while minimizing the risk of bearing failures due to misalignment. The motor and the gear mechanism are matched exactly to work together and require no separate design and mounting procedures, thus reducing engineering costs.
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  • Brushless Motor
    Brushless Motor
    Brushless motors used in servomotors by Rozum Robotics is a lineup of compact high-torque AC motors designed as frameless rotor and stator kits. The brushless technology employed in the drives enables packing impressive power into a compact footprint, while minimizing friction-induced power losses and ensuring noise- and spark-free operation. With low cogging torque, FMI-series products provide smooth rotation without jerkiness.
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  • Servo Box
    Servo Box
    Servobox solution allows for the following easy and quick integration of RDrive servos into your application, safe and correct operation of RDrive servos in the designed range of loads as well as precise control of RDrive servo motion via the Application Programming Interface.

    Servobox unit is offered as an option to RDrive servos

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  • High-precision control
    Two 19-bit absolute magnetic encoders integrated into RDrive servos enable angular accuracy of 0.01 degree, including in heavy-duty applications.
  • Integrated controller
    Processes feedback from encoders and temperature sensors, while enabling highly dynamic response to control commands to deliver top engine performance.
  • High torque
    A built-in strain-wave gearhead enables reducing speed to increase torque by 100 times (gear ratio 1:100). Thanks to its zero backlash, the gear adds power to RDrive engines with no negative effect on efficiency or performance.
  • Compact size
    Less space taken by our servo motors and more space for fancy high-tech add-ons in your machines. With diameters from 53 to 115 mm, the drives can fit easily into constricted environments.
  • API control
    Python or C—you can use your preferred technology stack to implement motion control. API functions ensure easy setup and operation of RDrive motors to enable motion to your exact requirements.
  • Hollow-shaft design
    Seamless integration without impacting the overall dimensions of your machine. You can use the hole at the servo centre to pass through utilities or structural elements—cabling, pneumatic or hydraulic hosing, air supply tubes, etc.
Industrial automation
Antenna positioning

Boasting compactness and precise positioning capability, servo actuators are employed in a variety of tasks in robotics. The engines move robot joints, operate work tools, or rotate wheels in self-propelling mechanisms. Products driven with the motor type vary from hobby models to giant industrial robots.

Servos are quick and easy to embed into a robot body. Using micro or nano modifications, inventors create robotic hands with dexterity of movements close to a human limb. Multiple servos can be connected on the same power chain, allowing varied and flexible robot configurations.


Known for great controllability, servos cope perfectly well with steering unmanned aerial vehicles, such as drones. The flying devices are designed as multi-propeller systems, where each propeller needs a drive and the total of drives should be able to work in sync.

With high torque output, servo motors provide required driving power—and more. Small dimensions of the drives allow their smooth integration into drones of various sizes. Availability of motion feedback and highly responsive control enable accurate navigation—from launching to landing.

Industrial automation

In the domain, servo motor applications cover various machinery: filling and packaging, metal and wood cutting, trimming, as well as CNC and textile handling machines. Servomechanisms provide such valuable benefits as simultaneous control over multiple work axes and ease of integration, including into enterprise management systems.

Feedback allows to detect abnormal moves and ensure strict compliance with command input. Turn, cut, trim, and other processing operations can be performed with consistency and uniformity. Servo motors are associated with reduced maintenance costs and remarkable accuracy due to eliminated mechanics, such as backshafts, pulleys, etc.

Antenna positioning

In these systems, servos communicate with a specialized software that calculates coordinates for a panel to soak up sunlight or an antenna to receive a signal. The software commands to servos to move, while also processing feedback from the drives.

In this way, servos are able to provide ultra-accurate angular displacement to follow the sun or signal as required. Closed-loop governance and high holding torque make it possible to retain positions as long as necessary.

Purchase, Delivery & Service

  • 1
    Place an Order
    All it takes to place an order is to submit an online request, send us an email, or give us a call. Our technician will advise you on a proper product
  • 2
    Make a Payment
    We issue an invoice based on agreed terms and you pay it up - just as simple as that. If needed, our managers will guide you through the process
  • 3
    Wait for Delivery
    Average lead time for our orders is up to six weeks. We will deliver the purchase right to your door—wherever the door is located
  • 4
    All the products are covered with a 1-year warranty. Each of our customers gets personalized LIVE tech support from the engineering team when requested
Easy to get—easy to use
Designed with the plug-and-run concept in mind, our RDrive motion solutions are easy to set up and operate. Instructions, drawings, and other information as required for seamless and quick integration are available on our website. When you need more specific advice, engineers at Rozum Robotics are at your service to guide you through the adoption process and address operating issues, if any.


  • EAC
    • Complete servo motors RD DC 48V frameless electric motors FMI type (AC 48V power supply). EAC Declaration.

      Registration number EAC Declaration.
    • Group controller SBX 2 type for servomotors (DC 48V power supply).

      Registration number EAC Declaration.


1. Is there an upper voltage limit for the RD60 drives? The datasheet states 48V but we are wondering if possible to go higher?

The weakest component in the schematics rated for 60V maximum, so we set software limits to 52V to have a voltage gap for safety. Servos are tested and proven to work in this voltage range. We didn't recommend to set this limit higher than 52V.

2. I need to read angle on a computer by visual studio based application. What packages do I need?

This can be done via API. API can be compiled in the visual studio using mingw-gcc

3. What is the difference between RDrive 60 and RDrive 70? The same motor with different gearbox or a different motor? Why less power on RDrive 70?

RDrive 60 and RDrive 70 have different frameless motors inside. The power is different because of the rated torque and speed are different. Here is the formula for power calculation:
Power (W) = Speed (Rpm) * Torque (Nm) /9.55
For RDrive60: 39Nm * 55rpm / 9.55 = 225W
For RDrive70: 49Nm * 30rpm / 9.55 = 155W

4. Can we operate in temps above 35dC with a derating applied to the torque? If so what is the derating for 40dC and 45dC?

RDrive servo motors can operate at an ambient temperature range 0....+35 dC. The thermal limit is +85 degrees. The higher the ambient temperature, the shorter the time delta before the safety system gets activated (85-35=50 dC - thermal range). If the ambient temperature is 40 or 45 dC the RDrive servo motors are expected to be operating without derating the torque. But the time delta and the thermal range will be shorter and the safety system gets activated faster. To avoid this there are two options: you can either choose a servo with a higher rated torque and use it a higher ambient temperatures making it bear a smaller load or apply additional cooling system and use the servo that exactly meets your torque parameters.

5. Is there a process for retuning the motors when the customer change the loading conditions? Do the motors support external feedback like a linear encoder on the load?

Built in control system (controller) allows for a critical mistake ±0.02° throughout the whole dynamic range (there's no need for retuning when the customer changes the load). Static error is ±0.005°. Max error during the accelerating stage and the braking phase: ±0.1° when the acceleration is 3 radian per sec2 and ±0.2° at 5 radian per sec2.
Currently we are working on the advanced functionality "feed forward". Expected delivery date of the feature - Q1'19. We assume that the max error will be 0.02-0.05 throughout the whole range. If the Customer would require 10+ motors, we integrate the feature beforehand.
As for the linear motor, for the moment it is not possible to use an external feedback. If the Customer would require that feature (depending on the Quantity request) we could develop a motor with no internal controller but designed for use with an external controller. You can use a different controller including those supporting an external feedback like (a linear encoder).