8P 8 mm Planetary Gearbox - Technical Datasheet v1.0¶
Status: Public engineering evaluation reference
Release date: 2026-10-06
The SigGear 8P is a 8 mm planetary gearbox platform with one- to four-stage configurations. Performance values below are consolidated from the current canonical product page. Mechanical-interface details are linked to the controlled 2D drawing reference released for this model.
Key Specifications¶
| Parameter | Public value |
|---|---|
| Nominal outer diameter | 8 mm |
| Number of stages | 1-4 |
| Gearbox length range | 10.15–18.10 mm |
| Reduction ratio range | 3.8:1–731.16:1 |
| Rated allowable torque range | 0.2–0.4 kgf·cm |
| Maximum momentary torque range | 0.4–0.8 kgf·cm |
| Efficiency range | 66–90% |
| Backlash at no load | ≤ 1.5° |
| Continuous permissible input speed | ≤ 8,000 rpm |
| Operating temperature range | −40 to 120 °C |
Maximum momentary torque is not a continuous working rating.
Stage, Ratio and Performance¶
| Stages | Gearbox body length L | Available ratios | Rated allowable torque | Maximum momentary torque | Efficiency |
|---|---|---|---|---|---|
| 1 | 10.15 mm | 3.8 / 4.5 / 5.2 | 0.2 kgf·cm | 0.4 kgf·cm | 90% |
| 2 | 12.80 mm | 14.4 / 17.1 / 19.8 / 20.3 / 23.4 / 27 | 0.25 kgf·cm | 0.5 kgf·cm | 80% |
| 3 | 15.45 mm | 54.9 / 65 / 75.1 / 76.95 / 88.9 / 91.1 / 102.75 / 105.3 / 121.7 / 140.6 | 0.3 kgf·cm | 0.6 kgf·cm | 73% |
| 4 | 18.10 mm | 208.5 / 246.9 / 285.3 / 292.4 / 337.9 / 346.3 / 390.46 / 400.14 / 410.1 / 462.4 / 473.85 / 534.3 / 547.56 / 632.74 / 731.16 | 0.4 kgf·cm | 0.8 kgf·cm | 66% |
Published Load / Shaft Limits¶
| Parameter | Public value |
|---|---|
| Radial load, 10 mm from flange | ≤ 0.4 kgf |
| Shaft axial load | ≤ 0.1 kgf |
| Radial shaft play | ≤ 0.04 mm |
| Thrust shaft play | ≤ 0.15 mm |
Only values currently published for 8P are shown. Do not transfer limits from another frame size.
Motor Matching Reference¶
- Adapted DC motor nominal voltage: 3–36 VDC
- Adapted DC motor power: below 2.5 W
These are motor-matching conditions, not electrical ratings of the mechanical gearbox.
Mechanical Interface and CAD¶
View 8P Mechanical Interface v1.0
Download 8P Simplified STEP - 4-Stage Reference
A simplified public 4-stage STEP reference is released for early packaging and mechanical Design-In. The detailed full-assembly STEP remains configuration-controlled and request-only because it contains internal planetary transmission geometry.
For final CAD, provide the selected ratio, stage count and motor interface.
Request CAD / Controlled Drawing
Selection Information Required¶
Please provide:
- Required output speed or reduction ratio
- Continuous and momentary output torque
- Motor voltage, power and speed
- Motor shaft diameter and length
- Motor mounting-hole pattern and locating pilot
- Output-shaft requirements
- Radial and axial loads
- Duty cycle and ambient temperature
- Backlash, noise and service-life targets
- Prototype and annual quantity
Related Product¶
Engineering Contact¶
Wanrong Wang
International Sales / Sales Engineer, SigGear
wangwanrong@siggear.com