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BCSA V4 Series RO

Bonsystems 1 미래 로봇 시대를 주도하는 스마트 액추에이터
Design with freedom
Assemble with ease
Drive with power
The custom robot actuator you’ve been looking for
Lightweight and slim profile
Stronger torque
Higher precision
Easy installation and service
The next evolution of
the cycloidal actuator,
BCSA V4

An actuator that combines design flexibility with reliable performance,
Introducing the BCSA V4.

Developed by Bonsystems, the BCSA V4 is a cycloidal-based robot actuator created with both simplified robot design and long-term operational reliability in mind. From smooth, powerful drive to efficient maintenance, it is built to deliver.

BCSA V4 360° Product Viewer

Product Specifications

Model Reduction Ratio Outer Dimension(mm) Thickness(mm) Motor Input Voltage DC(V) Motor Rated Current(A) Motor Maximum Current(A) Motor Rated Torque(Nm) Motor Rated Input Speed(RPM) Reducer Output Speed(RPM) Rated Torque(Nm) Peak Torque(Nm) Backlash(arcmin) Input Shaft Hollow Diameter(mm) Offset Both LC(mm) Weight(kg)
BCSA 107-011-O 11 107 53 48 15 50 1.3 3,600 327 10 31 10 arcmin or less 9 6.5 1.36
BCSA 107-015-O 15 107 53 48 15 50 1.3 3,600 240 13 40 10 arcmin or less 9 6.5 1.36
BCSA 107-019-O 19 107 53 48 15 50 1.3 3,600 189 16 48 10 arcmin or less 9 6.5 1.36
BCSA 107-029-O 29 107 53 48 15 50 1.3 3,600 124 23 71 10 arcmin or less 9 6.5 1.36
BCSA 107-039-O 39 107 53 48 15 50 1.3 3,600 92 30 92 10 arcmin or less 9 6.5 1.36
BCSA 107-049-O 49 107 53 48 15 50 1.3 3,600 73 30 92 10 arcmin or less 9 6.5 1.36
BCSA 127-011-O 11 127 54.5 48 20 62 4 2,000 182 31 92 10 arcmin or less 9 6.5 1.93
BCSA 127-015-O 15 127 54.5 48 20 62 4 2,000 133 40 119 10 arcmin or less 9 6.5 1.93
BCSA 127-019-O 19 127 54.5 48 20 62 4 2,000 105 48 144 10 arcmin or less 9 6.5 1.93
BCSA 127-029-O 29 127 54.5 48 20 62 4 2,000 69 71 212 10 arcmin or less 9 6.5 1.93
BCSA 127-039-O 39 127 54.5 48 20 62 4 2,000 51 92 276 10 arcmin or less 9 6.5 1.93
BCSA 127-049-O 49 127 54.5 48 20 62 4 2,000 41 92 276 10 arcmin or less 9 6.5 1.93
※ The specifications are based on design reference values, and actual performance may vary depending on operating conditions (such as motor efficiency, load, and temperature). Specifications are subject to change without prior notice due to product improvements.
ModelBCSA 107BCSA 127
Motor SpecificationsFB 89 (O.D 88.6, I.D 58.5 x 17.1)FB 109 (O.D 108.3, I.D 78 x 28)
Rated Voltage DC (V)4848
No-load Speed (RPM)4,8002,450
Rated Torque (Nm)1.34
Rated Speed (RPM)4,0002,000
Rated Current (A)1520
Maximum Torque (Nm)4.512
Peak Current (A)5562
No5 En 미래 로봇 시대를 주도하는 스마트 액추에이터
** A dash (-) means the section is left blank.

Product Introduction

A robot actuator from Bonsystems,
designed based on the real-world needs of engineers.

From flexible design to efficient operation and easy maintenance,
it delivers practical performance that makes a difference.

Bcsa Pro 4 미래 로봇 시대를 주도하는 스마트 액추에이터

01

Separate motor and reducer design

Easy customization
and maintenance

The hassle of having to purchase new equipment every time the gear ratio or
motor specifications changed has been solved with a modular dedicated housing design.

Bcsa Pro4 En 미래 로봇 시대를 주도하는 스마트 액추에이터

By separating the motor and reducer into independent modules,
it is easy to produce customized actuators according to required specifications.


Only the module that needs servicing can be selectively detached,
enabling quick on-site maintenance and support.

02

Stronger housing, stronger structure

Breaking the belief that
robot actuators must be heavy.
Bcsa Pro5 2 En 미래 로봇 시대를 주도하는 스마트 액추에이터
Light yet strong
aluminum anodized housing applied

03

Less heat, longer life

Bcsa Pro6 2 미래 로봇 시대를 주도하는 스마트 액추에이터

A heat dissipation structure is applied to the housing to
quickly release heat generated during operation to the outside.

Prevents component damage and shortened lifespan caused by heat,
maintaining stable performance for a longer time.

04

Same size and components, gear ratio as you wish!

Robot actuator specification customization

From 11:1
Bcsa127 3 미래 로봇 시대를 주도하는 스마트 액추에이터
to 49:1 and beyond

Provides the optimal gear ratio for
operating conditions without adding parts or changing the appearance.

05

Slimmer profile, broader possibilities

Free your design from space limitations.
Bcsa Ver2 미래 로봇 시대를 주도하는 스마트 액추에이터
60.5mm
Bcsa Ver4 08 미래 로봇 시대를 주도하는 스마트 액추에이터
54.5mm
* Based on BCSA V1 130 and BCSA V4 127

With a structure optimized for robot design,
it frees you from design constraints and offers flexible design options.

Bring designs once left to imagination into reality.

06

Cross-roller bearings

for unwavering stability
Ar2 En 미래 로봇 시대를 주도하는 스마트 액추에이터

Stronger durability compared to conventional ball bearings

Maintains stable rotation and torque transmission
even under high-load conditions.

07
The standard for precise movement?

Low backlash!

Reduced unnecessary gaps to minimize energy loss.

Arrow En 미래 로봇 시대를 주도하는 스마트 액추에이터
10A 미래 로봇 시대를 주도하는 스마트 액추에이터
Untitled 9 4 미래 로봇 시대를 주도하는 스마트 액추에이터
Compact size specialized for robot upper body, Discover the BCSA V4 RI version.
Frequently Asked Questions
What should I do if I don't know the model name?

If you are unsure about the specifications of a model when making a purchase inquiry, please refer to the detailed specifications for each model on the product page before contacting us.

Please include details about the intended application and desired specifications in your inquiry. Providing detailed information allows our team to recommend the most suitable product for your needs.
For reducer purchases, it is generally helpful to provide the model and specifications of the motor you are using (or plan to use), the intended application, and the required specifications.

Provide the specifications, applications, and purposes of your desired product, and Bonsystems Co., Ltd. will support you with robot design, engineering, and hardware manufacturing through the selection of our cutting-edge smart actuator (BCSA).
For detailed inquiries regarding development, please use the contact form below.

Yes, it is possible. If you provide the required specifications or the product information you prefer, we can integrate them during the manufacturing process as a customized option. You may also specify partner products or particular brands, and we will reflect them accordingly.

The RO version uses a frameless outer torque motor, which allows it to deliver high torque even with a slim profile. Thanks to this characteristic, it is well-suited for lower-body actuation of humanoid robots where weight support and strong power are essential.

The RI version, on the other hand, applies a frameless inrunner torque motor, which offers a smaller diameter and faster responsiveness. This makes it more suitable for arm actuation of humanoid robots where agile movement is required. Both products belong to the V4 Series, so you can select the most suitable version depending on the required torque, size, and application.

BCSA V4 Series
Model Reduction Ratio Outer Dimension(mm) Thickness(mm) Motor Input Voltage(V) Motor Rated Current(A) Motor Maximum Current(A) Motor Rated Torque(Nm) Motor Rated Input Speed(RPM) Reducer Output Speed(RPM) Rated Torque(Nm) Peak Torque(Nm) Backlash(arcmin) Input Shaft Hollow Diameter(mm) Offset Both LC(mm) Weight(kg)
BCSA 107-011-O 11 107 53 48 15 50 1.3 3,600 327 10 31 10 arcmin or less 9 6.5 1.36
BCSA 107-015-O 15 107 53 48 15 50 1.3 3,600 240 13 40 10 arcmin or less 9 6.5 1.36
BCSA 107-019-O 19 107 53 48 15 50 1.3 3,600 189 16 48 10 arcmin or less 9 6.5 1.36
BCSA 107-029-O 29 107 53 48 15 50 1.3 3,600 124 23 71 10 arcmin or less 9 6.5 1.36
BCSA 107-039-O 39 107 53 48 15 50 1.3 3,600 92 30 92 10 arcmin or less 9 6.5 1.36
BCSA 107-049-O 49 107 53 48 15 50 1.3 3,600 73 30 92 10 arcmin or less 9 6.5 1.36
BCSA 127-011-O 11 127 54.5 48 20 62 4 2,000 182 31 92 10 arcmin or less 9 6.5 1.93
BCSA 127-015-O 15 127 54.5 48 20 62 4 2,000 133 40 119 10 arcmin or less 9 6.5 1.93
BCSA 127-019-O 19 127 54.5 48 20 62 4 2,000 105 48 144 10 arcmin or less 9 6.5 1.93
BCSA 127-029-O 29 127 54.5 48 20 62 4 2,000 69 71 212 10 arcmin or less 9 6.5 1.93
BCSA 127-039-O 39 127 54.5 48 20 62 4 2,000 51 92 276 10 arcmin or less 9 6.5 1.93
BCSA 127-049-O 49 127 54.5 48 20 62 4 2,000 41 92 276 10 arcmin or less 9 6.5 1.93