Description
The CHIHAI CHR-GM25-BK370 is a compact high-speed brushed DC gear motor combining a powerful 370 motor with a 25mm all-metal reduction gearbox.
Designed for robotics, RC vehicles, smart cars, automation mechanisms and DIY projects, the motor is available in multiple gear ratios from 4.4:1 to 478:1, allowing users to select the appropriate balance between output speed and torque.
The gearbox uses metal gears for improved durability, while the motor features copper windings and replaceable extended carbon brushes. A 4mm D-shaped output shaft provides reliable coupling to wheels, hubs, couplers and other mechanical components.
Performance data is available for both 6V and 12V operation.
Key Features
- 25mm diameter metal gear motor
- High-speed 370 brushed DC motor
- 6V and 12V operation
- All-metal gearbox
- Multiple gear ratios from 4.4:1 to 478:1
- 4mm D-shaped output shaft
- Copper motor windings
- Extended replaceable carbon brushes
- Up to 26W maximum power at 12V
- Compact design for robotics and RC applications
- Custom 24V version may be available
Specifications
| Specification | Value |
|---|---|
| Brand | CHIHAI |
| Model | CHR-GM25-BK370 |
| Motor Type | Brushed DC Gear Motor |
| Motor | 370 Brushed DC Motor |
| Gearbox Type | Metal Gearbox |
| Gear Material | Metal |
| Gearbox Diameter | 25 mm |
| Operating Voltage | 1.5–12V DC |
| Reference Voltages | 6V / 12V |
| Custom Voltage | 24V available according to supplied information |
| Output Shaft | 4 mm D-Shaped Shaft |
| Shaft Flat | 3.5 mm |
| Standard Shaft Extension | 12 mm shown in drawing |
| Motor Body Length | 29.3 mm |
| Approx. Overall Diameter | 25 mm |
| Approx. Overall Length | 48.5–59 mm, depending on ratio |
| Approx. Weight | 85 g, varies by gear ratio |
| Maximum Power @ 6V | 8 W |
| Motor Input Speed @ 6V | 10,000 RPM |
| Maximum Power @ 12V | 26 W |
| Motor Input Speed @ 12V | 20,000 RPM |
| Maximum Permitted Gearbox Load | 8.0 kg·cm / 0.8 N·m |
Important: Do not exceed the specified maximum gearbox load of 8.0 kg·cm (0.8 N·m), as excessive loading may damage the gears.
Gear Ratio & Gearbox Length
| Gear Ratio | Gearbox Length |
|---|---|
| 4.4:1 | 19.0 mm |
| 10:1 | 19.0 mm |
| 20:1 | 19.0 mm |
| 34:1 | 21.5 mm |
| 45:1 | 24.0 mm |
| 57:1 | 24.0 mm |
| 75:1 | 26.5 mm |
| 100:1 | 26.5 mm |
| 125:1 | 29.0 mm |
| 217:1 | 29.0 mm |
| 478:1 | 29.0 mm |
6V Performance
| Gear Ratio | No-Load Speed | Rated Speed | Rated Torque | Rated Current |
|---|---|---|---|---|
| 4.4:1 | 2250 RPM | 1750 RPM | 0.03 N·m | ≤1.4 A |
| 10:1 | 1000 RPM | 790 RPM | 0.06 N·m | ≤1.4 A |
| 20:1 | 490 RPM | 390 RPM | 0.12 N·m | ≤1.4 A |
| 34:1 | 280 RPM | 230 RPM | 0.20 N·m | ≤1.4 A |
| 45:1 | 220 RPM | 175 RPM | 0.27 N·m | ≤1.4 A |
| 57:1 | 175 RPM | 135 RPM | 0.34 N·m | ≤1.4 A |
| 75:1 | 130 RPM | 100 RPM | 0.44 N·m | ≤1.4 A |
| 100:1 | 100 RPM | 80 RPM | 0.59 N·m | ≤1.4 A |
| 125:1 | 80 RPM | 60 RPM | Max. load limited to 0.8 N·m | ≤1.4 A |
| 217:1 | 45 RPM | 37 RPM | Max. load limited to 0.8 N·m | ≤1.4 A |
| 478:1 | 20 RPM | 18 RPM | Max. load limited to 0.8 N·m | ≤1.4 A |
No-load current at 6V: ≤320mA.
Stall current: ≤8A.
12V Performance
| Gear Ratio | No-Load Speed | Rated Speed | Rated Torque | Rated Current |
|---|---|---|---|---|
| 4.4:1 | 4500 RPM | 3500 RPM | 0.05 N·m | ≤2.7 A |
| 10:1 | 2000 RPM | 1580 RPM | 0.10 N·m | ≤2.7 A |
| 20:1 | 980 RPM | 780 RPM | 0.21 N·m | ≤2.7 A |
| 34:1 | 580 RPM | 460 RPM | 0.34 N·m | ≤2.7 A |
| 45:1 | 440 RPM | 350 RPM | 0.44 N·m | ≤2.7 A |
| 57:1 | 350 RPM | 275 RPM | 0.59 N·m | ≤2.7 A |
| 75:1 | 260 RPM | 210 RPM | 0.69 N·m | ≤2.7 A |
| 100:1 | 200 RPM | 160 RPM | Max. load limited to 0.8 N·m | ≤2.7 A |
| 125:1 | 160 RPM | 130 RPM | Max. load limited to 0.8 N·m | ≤2.7 A |
| 217:1 | 90 RPM | 75 RPM | Max. load limited to 0.8 N·m | ≤2.7 A |
| 478:1 | 40 RPM | — | Max. load limited to 0.8 N·m | ≤2.7 A |
No-load current at 12V: ≤600mA.
Stall current: ≤16A.
Applications
- RC cars and trucks
- Smart robot cars
- Mobile robots
- Robot drive mechanisms
- DIY robotics
- Automation equipment
- Small electric mechanisms
- Educational robotics
- Motorized wheels and platforms
- Compact mechanical drive systems
Package Includes
1 × CHR-GM25-BK370 DC Gear Motor
Gear ratio and voltage are supplied according to the selected variant.
FAQ
What is the difference between the 6V and 12V versions?
The 12V configuration operates at substantially higher motor and output speeds. Refer to the performance tables for the speed, torque and current specifications of each voltage.
Does this motor use metal gears?
Yes. The supplied product information specifies an all-metal reduction gearbox.
What is the output shaft diameter?
The motor uses a 4mm D-shaped output shaft with a 3.5mm flat dimension.
Can I order a 24V version?
The supplied manufacturer information indicates that a customized 24V version is available. Contact us before ordering for availability and specifications.
Which gear ratio should I choose?
Lower gear ratios provide higher output speed. Higher ratios provide lower speed and greater reduction, but the gearbox load must remain within its specified limit.
