SG-8021 Technical Datasheet v1.0¶

Status: Public engineering evaluation reference
Release date: 2026-10-06

SG-8021 is a 100 mm low-profile integrated planetary robot joint actuator with a 9.25:1 reduction ratio, 10 Nm rated output torque and 160 rpm rated output speed.

This page consolidates values already published on the current SG-8021 product page. Driver, encoder, communication and closed-loop functions depend on the ordered configuration and must be confirmed in the quotation.

Key Performance¶

Parameter	Published value
Transmission structure	Planetary gearbox
Outer diameter	100 mm
Product thickness	42.6 mm
Reduction ratio	9.25:1
Backlash	15-20 arcmin
Operating voltage	24-48 VDC
Motor power	213 W
Rated output speed	160 rpm
No-load output speed	240 rpm
Rated output torque	10 Nm
Peak output torque	30 Nm
Weight	671 g
Allowable radial force	1300 N
Allowable axial force	550 N

Warning

Peak torque is not a continuous rating. Peak-torque duration, current limit, duty cycle and thermal suitability must be confirmed for the actual application.

Motor and Electrical Parameters¶

Parameter	Published value
Phase inductance	290 uH
Phase current full scale	33 A
Rated bus current	12 A
Static working bus current	0.08 A
Motor torque constant	0.046 Nm/A
Motor structure	21 pole pairs
Thermistor	10 kOhm, B3435, +/-1%
Back-EMF constant	0.143 Vs/rad
Motor speed constant	63 rpm/V

Driver-Equipped Configuration¶

The current public SG-8021 product page documents a driver-equipped configuration with functions that can include:

FOC closed-loop control
Position control
Velocity control
Torque control
MIT-style motion control
PID parameter configuration
Calibration and user-zero configuration
CAN communication
USB Type-C configuration / debugging

RS485, EtherCAT and other expansion functions are project-specific and require engineering confirmation.

Mechanical and Load Evaluation¶

For early project screening, use the public envelope and load values above.

Final suitability depends on:

Mounting structure
Load direction and moment arm
Duty cycle
Shock load
Bearing-life requirement
Cable / connector orientation
Driver-equipped or non-driver configuration

View SG-8021 Mechanical Interface Reference

Internal Structure Reference¶

The current SG-8021 product page includes a real exploded product photograph showing the planetary transmission, motor and a driver-board configuration.

View SG-8021 Product and Exploded Structure

The photograph is an engineering reference image, not a manufacturing drawing. Internal geometry and component details shown in the image should not be used as controlled production dimensions.

CAD, Drawings and Integration Documentation¶

A public STEP model is not currently released in this repository for SG-8021.

Detailed STEP, controlled drawings, connector / cable information and configuration-specific control documentation should be requested for the intended project.

Request CAD, Drawing or Integration Files

Selection Information Required¶

Please provide:

Application and joint position
Rated and peak torque
Required peak-torque duration
Required output speed
Operating voltage
Installation envelope
Duty cycle
Radial and axial load condition
Driver, encoder and communication requirements
Prototype quantity and estimated annual quantity

SG-8021 Product Page Custom Robot Joint Development Robot Joint Selection Guide

Engineering Contact¶

Wanrong Wang
International Sales / Sales Engineer, SigGear
wangwanrong@siggear.com