Harmonic Drive LLC | 42 Dunham Ridge, Beverly, MA 01915 | 800-921-3332
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RSF-5B IDT Supermini Actuator

The compact RSF-5 miniature actuator with a zero backlash Harmonic Drive® gear delivers high torque with exceptional accuracy and repeatability. The actuator features an integrated servo drive utilizing CANopen® communication. This evolutionary product eliminates the need for an external drive and greatly improves wiring while retaining high-positional accuracy and torsional stiffness in a compact housing. This new miniature actuator product is ideal for use in robotics.

Since it communicates via CANopen, only 4 conductors are needed: CANH, CANL, +24VDC, 0VDC. A single-turn 14bit (16384 cpr) gear output sensing encoder has been integrated. See also FHA-IDT for more actuators with integrated servo drives.

Key Features:

  • Actuator + Integrated Servo Drive with CANopen® Communication
  • 24VDC Nominal Supply Voltage (7VDC to 30VDC range)
  • Single Cable with only 4 conductors is needed:
    CANH, CANL, +24VDC, 0VDC
  • Zero Backlash Harmonic Drive® Gearing
  • Replaceable flex-rated cable assembly with front and rear exiting options
  • Input Sensing Encoder: 14 bit resolution (16,384 cpr)
  • Control Modes: Torque, Velocity, Position, CSP, CSV, CST
  • Harmonic Drive® HDL Software


  • Flex-rated extension cables with sealed connectors


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Our team can help you find the right actuator for your application!

Ordering Code RSF-5B Miniature with Integrated Servo Drive

RSF - 5 B - 50 - IDT14b - PT1 - SP
1 2 3 4 5 6 7 8

1. Model

RSF Supermini Series

2. Size


3. Design Version


4. Gear Ratio

30, 50, 100

5. Encoder Type and Resolution

IDT14b - Integrated Drive
14bit resolution absolute encoder on motor input

6. Output

Blank - Shaft Output
F - Flange Output

7. Cable Exit Options

PT1 - Rear exit cable
PT5 - Front exit cable

8. Special specification

Blank - Standard product
SP____ - Special specification code


Model RSF-5B
Gear Ratio 30 50 100
Maximum Torque N.m 0.5 0.9 1.4
Maximum Speed rpm 150 90 45
Torque Constant
Nm/A(rms) 0.3 0.54 1.1
Maximum Current A(rms) 2.3 2.2 1.7
Allowable continuous current A(rms) 1.11 0.92 0.76
EMF Constant V/(rpm) 0.04 0.07 0.13
One-way Positioning Accuracy arc-min 4 3 3
Allowable Moment Load Nm 15
Phase resistance Ω(20°C) 0.82
Phase inductance mH 0.27
Input Power supply V 24VDC (+7 to +30VDC)
Number of Poles 8
Moment Stiffness Nm/rad 7.41 x 102
Moment of Inertia
kgm2 7.09 x 10-5 1.97 x 10-4 7.88 x 10-4
Encoder Type and resolution

IDT14b - Integrated Drive
14bit resolution absolute encoder on motor input
Output Shaft Resolution*1 counts/rev 491,520 819,200 1,638,400
Mass g 77
Ambient environment specification 0 to 40° C ambient operational temperature range, Storage temperature is -20 to 60° C with humidity 20 to 80%RH (non-condensing). Free from dust, dirt, metallic powder, corrosive gas, flammable gas, oil mist, and others. Avoid outdoor use or direct sunlight. Altitude: 1,000 m or less. Motor insulation: 100 MΩ (500 VDC) or higher. Dielectric strength: 1500 VAC/1 min. Insulation class: B

* Table shows typical output values

*1 Motor ABS encoder resolutions are obtained by (motor encoder resolution) x (gear ratio)

Outline Dimensions

Flange Output, Rear Exit Cable

Flange Output, Front Exit Cable

Shaft Output, Rear Exit Cable

Shaft Output, Front Exit Cable

Optional Extension Cable: 3 Lengths (ZZ) Available: 3m (03), 5m (05), 10m (10)


HDL-IDE 3.0 Software

HDL-IDE 3.0 software provides the ability to setup or commission the RSF-5B Mini Integrated actuator without connecting to a CANopen master controller. A single actuator can connect to a personal computer or laptop with a CAN communication converter and a power supply. All 256 parameters, including the tuning parameters and 256 general user variables can be set and stored to be recognized by the CANopen master controller operating the specific application. The following are some of the features included in HDL-IDE 3.0 software:

  • Torque Mode and Graph

  • Velocity Mode and Graph

  • Position Mode and Graph

  • Homing Mode

    • Limit Switch

    • Current Position

    • Hardstop Homing

  • Step Response

  • Bode Plot

  • Parameter List

  • Virtual Mode (shown)

for more information.


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