
Overview
The CHIHAI MOTOR CHS-GM12-10BY is a miniature geared stepper motor with a 55 mm M4 threaded output shaft. Choose a real reduction ratio and a motor-only, flange-nut, open-driver or enclosed-driver package for compact rotary positioning mechanisms.
Features
- Two-phase, four-wire step control with a metal reduction gear train.
- M4-0.7 threaded shaft with an optional matching flange nut.
- Five selectable ratios and package-specific driver choices.
- Attached four-wire lead and miniature connector.
Specifications
| Brand / model | CHIHAI MOTOR / CHS-GM12-10BY, 55 mm M4 threaded shaft |
| Motor structure | Two-phase, four-wire permanent-magnet geared stepper; all-metal gear train |
| Retail ratios | 10:1, 30:1, 50:1, 100:1 and 298:1 |
| Output shaft | M4-0.7 thread, 55.0 mm projection; 0.7 mm thread pitch |
| Mechanical envelope | 10 × 12 mm front reference; 9 mm mounting-hole spacing; 2 × M1.6 holes |
| Drawing dimensions | 9 mm front gearbox reference, 10.5 ±0.2 mm motor section, 6.0 mm rear reference, 0.7 mm shoulder and 1.0 mm feature |
| Cable / connector | 75 ±10 mm lead; UL1571 AWG30; 51021-0400 single-row white housing; 1.25 mm pitch |
| Motor net mass reference | Approximately 14 g; varies with ratio. This is not packaged shipping mass. |
| Electrical parameter reference | 5.0 V DC with driver IC 6219; 128 mA per phase; 39 Ω ±7% per phase; 14.3 mH per phase |
| Operating guidance | 5–12 V application range with a compatible current-controlled stepper driver; motor winding limits and controller supply limits are different |
| Maximum gearbox torque | 3.0 kgf·cm rotational limit; not axial thrust or a continuous torque promise |
Ratio and Torque Reference
The following table uses the 5 V / IC 6219 electrical reference. The selectable 10:1 version has no corresponding row here; do not apply another ratio's torque or step angle to it.
| Nominal ratio :1 | Exact ratio | Output step angle ° | Holding kgf·cm | Pull-out kgf·cm |
|---|---|---|---|---|
| 30 | 29.47 | 0.61 | 0.36 | 0.09 |
| 50 | 51.1 | 0.35 | 0.6 | 0.15 |
| 100 | 99.3 | 0.18 | 1.2 | 0.3 |
| 298 | 297.9 | 0.06 | Not separately specified | 0.9 |
Holding torque and pull-out torque describe different conditions. The maximum gearbox torque is 3.0 kgf·cm. Frequency labels give self-starting more than 1200 PPS and response more than 900 PPS; these differently labeled figures do not establish a reliable guaranteed ceiling. Set starting frequency and acceleration for the actual load and driver.
Motor Input Frequency and Current Reference
These separate full-step test references use a 39 Ω motor. Frequencies and rpm refer to the motor input before reduction; divide motor rpm by the exact gear ratio for an output-speed reference. Higher frequency reduces available torque. Choose an operating point without marked resonance; low-voltage references do not override the main model's driver and current requirements.
| Test supply | High Hz | Motor rpm at high Hz | Current at high Hz | Low Hz | Motor rpm at low Hz | Current at low Hz | Locked-phase current, 0 Hz |
|---|---|---|---|---|---|---|---|
| 6.0 V | 1400 | 4200 | ≤0.12 A | 800 | 2400 | ≤0.18 A | ≤0.30 A |
| 5.0 V | 1300 | 3900 | ≤0.085 A | 700 | 2100 | ≤0.155 A | ≤0.25 A |
| 3.7 V | 800 | 2400 | ≤0.085 A | 500 | 1500 | ≤0.125 A | ≤0.19 A |
Supply voltage equals back EMF plus phase current times winding resistance. Use a suitable stepper driver and current setting. Monitor temperature during extended operation and provide cooling or rest intervals as needed. The 128 mA-per-phase parameter and this test table have different stated conditions.
Connection and Excitation
| Connector pin | Color | Phase reference |
|---|---|---|
| 1 | Brown | B |
| 2 | Black | B return |
| 3 | White | A |
| 4 | Red | A return |
White and red form one coil; brown and black form the other. Both the connection drawing and excitation table identify brown as B, black as B return, white as A and red as A return. Check coil pairs and direction on the actual unit before connecting it to a driver. The two-phase full-step sequence energizes A/B, A-return/B, A-return/B-return and A/B-return in order; reversing the sequence reverses rotation. Do not connect a bare stepper motor directly like a brushed DC motor.
Mechanical Fit and Optional Flange Nut
The shaft drawing specifies M4-0.7 thread and 55 mm projection. Nominal thread advance is 0.7 mm per shaft revolution only with a matching restrained nut; it does not establish usable travel, linear accuracy, backlash or axial load capacity. A guide and carriage are separate mechanical components.
The optional nut has a 22 mm flange diameter, 10 mm body diameter, 12 mm overall length, 2 mm flange thickness and 8 mm section reference. Four 3 mm holes use a 16 mm spacing reference; the side drawing marks an M3 through feature. Confirm fit and clearances before machining or assembly.
Applications
Compact instrument adjustment, focus mechanisms, miniature robotic mechanisms and small positioning projects where the selected speed, torque, shaft and driver are suitable. Application examples do not include a robot, optical mechanism, linear guide, carriage or complete machine.
What's Included
- Motor Only: one selected-ratio motor with M4 threaded shaft and lead.
- Motor + Flange Nut: one motor and one flange nut.
- Motor + Open Driver: one motor and one pictured open control board.
- Motor + Enclosed Driver: one motor and one pictured enclosed control board.
- Motor + Flange Nut + Open Driver: one motor, one nut and one open board.
A DC power supply, external automation controller, carriage and complete machine are not included. The pictured open board is marked STEPCON-V1.1 and 5–18 V at its power connector. This is the board supply reference, not the motor phase rating. PUL, DIR and EN labels are visible; external signal timing and logic levels depend on the actual board revision. Match the board and motor current setting before use.
Installation and Operation
Use a compatible two-phase driver, verify coil pairs and support the driven mechanism. Avoid overload, stall and unsupported shaft loads. Keep mounting screws clear of internal components. Speed, noise and heating vary with drive mode, supply, load and duty cycle.
FAQ
Does every package include a nut or driver?
No. Only the accessories explicitly named in the chosen package are included.
Can the bare motor run directly from DC?
It needs a compatible two-phase stepper driver and an appropriate current setting.
Is it a complete linear actuator?
No. It is a geared stepper with a threaded rotary shaft; a nut is optional and the guide and carriage are separate.
Does the 10:1 option use the 30:1 torque figures?
No. The technical table does not give a 10:1 torque row.
Visual Details








