8–42 mm Planetary Gear Reducer Series¶
Product Overview¶
SigGear supplies miniature and compact planetary gear reducers with nominal outer diameters from 8 mm to 42 mm for robotics, medical devices, laboratory automation, precision instruments and compact industrial mechanisms.
The series is intended for projects that require a compact transmission and flexible integration with a motor, output shaft, mounting interface or sensor system. Final ratio, torque, speed, dimensions and motor matching depend on the selected diameter and project configuration.
Quick Selection Matrix¶
Use this table for preliminary frame-size selection. Values are the currently published ranges for each standard series. Final selection still depends on the exact stage count, reduction ratio, motor, duty cycle and mechanical interface.
| Model | Ø | Gearbox body length | Reduction ratio | Rated allowable torque | Maximum momentary torque | Backlash at no load | Adapted motor power |
|---|---|---|---|---|---|---|---|
| 8P | 8 mm | 10.15–18.10 mm | 3.8:1–731.16:1 | 0.2–0.4 kgf·cm | 0.4–0.8 kgf·cm | ≤ 1.5° | below 2.5 W |
| 10P | 10 mm | 10.25–18.50 mm | 3.5:1–428.7:1 | 1.3–2.0 kgf·cm | 2.6–4.0 kgf·cm | ≤ 1.5° | below 3 W |
| 12P | 12 mm | 11.35–19.60 mm | 3.5:1–509.1:1 | 2.0–4.2 kgf·cm | 4.0–8.4 kgf·cm | ≤ 1.5° | below 4 W |
| 14P | 14 mm | 15.2–26.6 mm | 3.75:1–443.3:1 | 3.5–6.0 kgf·cm | 7.0–12.0 kgf·cm | ≤ 1.5° | below 5 W |
| 16P | 16 mm | 17.55–30.45 mm | 3.85:1–459.5:1 | 4.0–9.0 kgf·cm | 8.0–26.0 kgf·cm | ≤ 1.5° | below 10 W |
| 20P | 20 mm | 20.1–34.5 mm | 4:1–1296:1 | 6.0–13.0 kgf·cm | 12.0–26.0 kgf·cm | ≤ 1.5° | below 20 W |
| 22P | 22 mm | 22.6–38.5 mm | 3.5:1–509.1:1 | 8.0–25.0 kgf·cm | 16.0–50.0 kgf·cm | ≤ 1.5° | below 25 W |
| 24P | 24 mm | 24.6–42.0 mm | 3.83:1–759.7:1 | 10.0–30.0 kgf·cm | 20.0–60.0 kgf·cm | ≤ 1.2° | below 28 W |
| 28P | 28 mm | 25.6–44.5 mm | 3.83:1–759.7:1 | 20.0–50.0 kgf·cm | 40.0–100.0 kgf·cm | ≤ 1.2° | below 30 W |
| 32P | 32 mm | 28.05–52.95 mm | 3.5:1–509.1:1 | 35.0–80.0 kgf·cm | 70.0–160.0 kgf·cm | ≤ 1.2° | below 100 W |
| 36P | 36 mm | 30.6–61.5 mm | 3.66:1–625:1 | 40.0–100.0 kgf·cm | 80.0–200.0 kgf·cm | ≤ 1.2° | below 150 W |
| 42P | 42 mm | 35.6–69.5 mm | 3.8:1–660.7:1 | 80.0–150.0 kgf·cm | 160.0–300.0 kgf·cm | ≤ 1.2° | below 200 W |
Torque values are preserved in the current published source unit, kgf·cm. Maximum momentary torque is not a continuous operating rating.
Open 8P–42P Datasheet & Mechanical Interface Library
How to Narrow the Model¶
A practical first-pass selection sequence is:
- Start with the installation diameter and eliminate frames that do not fit.
- Check rated allowable torque, not maximum momentary torque, for the normal operating point.
- Check the ratio range against the motor speed and target output speed.
- Check gearbox body length for the stage count likely to be required.
- Check the adapted-motor power range as a motor-matching reference.
- Open the selected model Datasheet and Mechanical Interface before finalizing the candidate.
Do not select only from outer diameter. A smaller frame may not satisfy torque or motor-interface requirements, while a larger frame may add unnecessary size.
Standard Models¶
The standard series includes 8P, 10P, 12P, 14P, 16P, 20P, 22P, 24P, 28P, 32P, 36P and 42P.
Each model now has a public Datasheet, Mechanical Interface reference and simplified public 4-stage STEP for early packaging and Design-In. Detailed full-assembly CAD remains configuration-controlled and request-only.
Typical Applications¶
- Micro robotics
- Small robotic grippers
- Miniature robotic arms
- Medical devices
- Laboratory automation equipment
- Optical adjustment mechanisms
- Precision instruments
- Smart hardware
- Compact actuators
- Mini pumps and valve mechanisms
- Inspection equipment
- Servo and automation modules
Motor Integration¶
Depending on the selected gearbox and project requirements, SigGear can evaluate integration with:
- Brushed DC motors
- Brushless DC motors
- Stepper motors
- Servo motors
- Customer-specified motor assemblies
Motor compatibility must be confirmed according to input speed, input shaft, mounting interface, power, duty cycle and required output performance.
Customization Options¶
Project-specific options may include:
- Reduction ratio
- Output shaft shape and length
- Input interface
- Mounting flange
- Housing and installation structure
- Motor integration
- Encoder or brake integration
- Cable and connector configuration
- Customer branding and labeling
Customization availability depends on the selected diameter, order quantity and engineering review.
Supply Configuration¶
SigGear can supply the planetary gearbox as a gearbox-only unit, or evaluate and match a motor based on the customer's specific application requirements to provide a complete motor + gearbox assembly.
Selection Information Required¶
Please provide:
- Application and installation position
- Preferred gearbox diameter
- Required reduction ratio
- Required continuous and peak output torque
- Required output speed
- Motor type and motor parameters
- Input and output shaft requirements
- Mounting method
- Backlash requirement
- Duty cycle
- Noise and service-life targets
- Estimated prototype and annual quantity
Datasheets, Mechanical Interfaces and CAD¶
Every standard 8P–42P frame size now has:
- a model-specific public Datasheet
- a public Mechanical Interface reference based on the reviewed controlled 2D drawing
- a simplified public 4-stage STEP for early packaging and Design-In
- configuration-matched controlled CAD available after engineering review
The detailed full-assembly STEP files are not published as raw public downloads because they contain internal planetary transmission geometry. Public simplified CAD intentionally omits the internal planetary transmission construction.
Open 8P–42P Public CAD Release v1.0
Open the Planetary Engineering Resource Library
Controlled production drawings and configuration-specific CAD are supplied after the model, stage count, ratio and motor interface are confirmed.
Published specifications must not be transferred from one diameter or stage configuration to another without confirmation.
Related Resources¶
Custom Planetary Gearbox Engineering Browse All Planetary Gearboxes Request CAD, Sample and Quote Micro Robotics Gear Motors and Compact Actuators Medical and Laboratory Micro Gear Motors
Contact SigGear¶
Wanrong Wang
International Sales, SigGear
wangwanrong@siggear.com