
Overview
The CHIHAI MOTOR CHF-GM12 gear reducer is a compact 12 x 10 mm square gearbox for appropriately matched N10, N20 and N30 motors. It contains a metal reduction assembly and is supplied with a separate motor-input pinion and two mounting screws. The motor is not included.
Features
- Open metal frame with precision-cut steel gears.
- Multiple reduction ratios and output-shaft lengths for compact mechanisms.
- 1 mm input-pinion bore for a matching motor shaft.
- Approximately 5 g gearbox mass.
Specifications
| Item | Specification |
|---|---|
| Model | CHF-GM12 |
| Product | Standalone square micro gear reducer; motor not included |
| Main footprint | 12 x 10 mm |
| Series body-depth references | 9 mm or 11 mm, depending on reduction configuration; see reference table |
| Net gearbox mass | Approximately 5 g |
| Motor families | N10, N20 and N30; matching shaft and mounting pattern required |
| Other compatible motor form | 12 mm diameter coreless motor with suitable threaded mounting holes and shaft |
| Input pinion bore | 1 mm; fit only a matching 1 mm motor shaft |
| Output shaft | 3 mm diameter D-shaft drawing reference, with selectable projection lengths; profile for the 1000:1 option is not specified |
| Output projections offered | 4.4, 5, 6.3, 7.7 and 10 mm in the actual listed combinations |
| Mounting interface table | Two diagonal nominal M1.6 holes, diagonal spacing 9.44 mm |
| Motor matching drawing | 2.4 +/-0.2 mm shaft extension; 1 mm shaft with -0.002/-0.008 mm tolerance; 2-M1.4 x0.3 motor thread callout |
| Gear construction | Precision-cut steel gears with open metal support plates |
| Normal operating temperature | -10 to +60 degrees C |
Ratio and Shaft Selection
| Reduction ratio | Output shaft projection and profile |
|---|---|
| 10:1 | 10 mm D |
| 20:1 | 10 mm D |
| 30:1 | 10 mm D |
| 50:1 | 10 mm D |
| 100:1 | 10 mm D |
| 150:1 | 10 mm D |
| 210:1 | 10 mm D |
| 298:1 | 10 mm D |
| 380:1 | 10 mm D |
| 1000:1 | 10 mm - Profile Unspecified |
| 10:1 | 4.4 mm D |
| 50:1 | 4.4 mm D |
| 100:1 | 4.4 mm D |
| 150:1 | 4.4 mm D |
| 298:1 | 4.4 mm D |
| 380:1 | 4.4 mm D |
| 298:1 | 7.7 mm D |
| 210:1 | 5 mm D |
| 210:1 | 6.3 mm D |
Choose one of the listed combinations. D identifies the D-flat shaft options; the 1000:1 selection specifies a 10 mm projection without defining its profile. The square frame is the offered construction. Rounded-frame and alternative steel-plate illustrations show other series constructions and are not separate options in this product.
Series Performance References
The table covers the gearbox family, including ratios that are not selectable here. Rated torque and momentary permitted torque are different limits. Do not use momentary torque as a continuous operating rating. Noise figures have no specified test distance or motor operating condition and are references rather than a guaranteed assembled-system noise level.
| Ratio | Stages | Rated torque (gf·cm) | Momentary torque (gf·cm) | Noise reference (dB) | Body envelope (mm) |
|---|---|---|---|---|---|
| 3:1 | 2 | 200 | 600 | <60 | 12 x10 x9 |
| 5:1 | 2 | 200 | 600 | <60 | 12 x10 x9 |
| 10:1 | 2 | 200 | 600 | <60 | 12 x10 x9 |
| 17:1 | 4 | 300 | 900 | <60 | 12 x10 x9 |
| 20:1 | 4 | 300 | 900 | <60 | 12 x10 x9 |
| 30:1 | 4 | 300 | 900 | <60 | 12 x10 x9 |
| 36:1 | 4 | 300 | 900 | <60 | 12 x10 x9 |
| 50:1 | 4 | 400 | 1200 | <60 | 12 x10 x9 |
| 63:1 | 4 | 400 | 1200 | <60 | 12 x10 x9 |
| 100:1 | 4 | 500 | 1500 | <60 | 12 x10 x9 |
| 110:1 | 5 | 500 | 1500 | <50 | 12 x10 x9 |
| 150:1 | 5 | 500 | 1500 | <50 | 12 x10 x9 |
| 210:1 | 5 | 800 | 2400 | <50 | 12 x10 x9 |
| 250:1 | 5 | 800 | 2400 | <50 | 12 x10 x9 |
| 298:1 | 5 | 800 | 2400 | <50 | 12 x10 x9 |
| 380:1 | 5 | 800 | 2400 | <50 | 12 x10 x9 |
| 372:1 | 7 | 1000 | 3000 | <40 | 12 x10 x11 |
| 625:1 | 7 | 1000 | 3000 | <40 | 12 x10 x11 |
| 800:1 | 7 | 1000 | 3000 | <40 | 12 x10 x11 |
| 1000:1 | 7 | 1000 | 3000 | <40 | 12 x10 x11 |
Motor Fit and Installation
The input pinion fits a 1 mm motor shaft. Confirm the shaft diameter, projection, threaded holes and diagonal hole spacing against the drawings before assembly. The mounting-interface table specifies nominal M1.6 and 9.44 mm diagonal spacing; the separate matching-motor drawing labels 2-M1.4 x0.3. Check the actual motor and supplied screws before threading parts together. Motor-family names alone do not establish fit for every version.
- Use a suitable press fixture to install the pinion squarely on the motor shaft.
- Support the rear motor shaft while pressing to avoid transferring damaging force through the motor.
- Align the gearbox and tighten the mounting screws gradually in three passes, keeping the assembly square and stable.
- Handle the staked/riveted gearbox carefully; dropping or rough handling can loosen the structure.
Input pinion tooth counts vary with reduction ratio and are not interchangeable across ratios. Use the pinion supplied with the selected gearbox. A matching 12 mm coreless motor may also be used only when its shaft and threaded mounting holes fit. The normal operating-temperature range is -10 to +60 degrees C; a special -30 degrees C construction is not included in these selections.
Applications
Use this reducer in small motor-driven mechanisms and compact prototypes that require reduced output speed. Select an appropriate motor, reduction ratio and operating load; the standalone gearbox has no electrical supply rating of its own.
What's Included
- One selected square CHF-GM12 gearbox.
- One matching input pinion with 1 mm bore.
- Two mounting screws.
Motor, power supply, motor driver and installation press fixture are not included. Motor-mounted application images illustrate compatibility, not additional package contents.
FAQ
Does this include an N20 motor?
No. This is a standalone gearbox with pinion and screws; choose a separately sourced motor that matches the shaft and mounting drawing.
Can I reuse one input pinion for every ratio?
No. Pinion tooth counts depend on reduction ratio. Use the matching pinion supplied with the selected gearbox.
Are all shaft lengths offered at every ratio?
No. Only the listed ratio and shaft combinations are available.
Visual Details







