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Rotary Actuator RSF supermini Series AC Servo Actuator


  • Compact, lightweight, high output
  • Standard lineup of actuators with a brake
  • High-precision positioning
  • Wide operation range
  • For 24VDC power supply
  • Robust structure (Flexible cable used for the encoder cable)

The RSF supermini series are compact, high torque, high rotational accuracy AC servo actuators combining a HarmonicDrive® with an ultra-small AC servo motor.
Coupled with the dedicated driver HA-680 for 24VDC power supply, the RSF supermini series delivers high rotational accuracy in compact machines and equipment.

Commercial Applications


AC Servo Actuator


  1. Model: RSF series AC servo actuator
  2. Model Nos: 3, 5
  3. Version symbol
  4. Reduction ratios of HarmonicDrive®: 30, 50, 100
  5. Encoder type E: Incremental encoder
  6. Encoder resolution 020: 200p/rev 050:500p/rev
  7. C: With connector (Standard product)
    BC: With brake and connector (model No. 5 only)
    No description: No option available
  8. No description: Standard product
    SP: Special product

AC Servo Driver


  1. Model: HA series
  2. Series: 680
  3. Rated output current:
    • 4:4A
  4. Corresponding sign
    • B: RSF Supermini series
  5. Input voltage: 24VDC

Extension cable

There are cables that connect the actuator and driver, and there are communication cables that connect the driver and personal computer.

Application cable Model
For motors EWA-M**-JST04-TN2
For encoders EWA-E**-JST09-3M14
Brake type EWA-B**-JST03-TMC
For EIA-232 HDM-RS232C (cable length: 1.5m)


This connector is used to connect each model driver. There are 2 types of connectors for the driver for different set types.

4 type set (CN1, CN2, TB1, TB2)
Model: CNK-HA68-S1
2 type set (CN2, TB2)
Model: CNK-HA68-S2 (If you will use an extension cable, this model must be used.)
  • * The extension cable for the encoder is required to connect with the driver.
  • * The extension cable for the brake is required for the actuator with brake.

Dedicated communication software (provided free of charge): PSF-520

This dedicated communication software is used to set/change parameters in the HA-680 driver.
The dedicated communication software can be from our website at []. Perform a full parameter setting for the HA-680 driver using the PSF-520 dedicated communication software.

Rated Table

Item/Model RSF-3C RSF-5B
Reduction ratio 30 50 100 30 50 100
Allowable continuous torque N·m 0.03 0.07 0.11 0.18 0.29 0.44
Permissible continuous rotational speed (output shaft) r/min 150 90 45 150 90 45
Allowable continuous stall torque N·m 0.04 0.08 0.12 0.28 0.44 0.65
Max. torque N·m 0.13 0.21 0.3 0.5 0.9 1.4
Inertia moment (GD2/4) (Note 3) Standard product kg・m2 0.11 x 10-4 0.29 x 10-4 1.17 x 10-4 0.66 x 10-4 1.83 x 10-4 7.31 x 10-4
With brake 0.11 x 10-3 0.31 x 10-3 1.23 x 10-3
Encoder resolution (Note 4) Pulse/rev 24,000 40,000 80,000 60,000 100,000 200,000
Mass Standard product g 31.0 (excluding the clamp filters) 66.0 (excluding the clamp filters)
With brake 86.0 (excluding the clamp filters)
Combined driver HA-680-4B-24 HA-680-4B-24
CAD data

Cover image

Actuator type Standard product DXF file DXF file
With brake DXF file
  • Note 1 The table shows values for the output shaft.
  • Note 2 The table shows the values when combined with the combined driver (HA-680-4B-24).
  • Note 3 The inertia moment is the total value of the motor shaft and HarmonicDrive® moment of inertia values converted to the output side.
  • Note 4 The encoder resolution is (motor shaft encoder resolution when multiplied by 4) x (reduction ratio).

Contact us

For any comments or questions for the products, please contact us by inquiry form or contact the nearest sales office.