Product overview
The AXR 9870 MG-D from Zhuhai SV Tech Co., Ltd. is a standard servo for model steering, control surfaces and mechanical actuation. Its construction combines a brushless motor, stainless steel gears and two bearings within a 40 × 20 × 40.4 mm body weighing 86 g. The cable measures 300 mm. Installation requires checking supply, signal pulse width, mounting holes and servo-arm connection. Before fabricating mounting parts, confirm the final mounting drawing and interface version because dimensional references may differ between drawings and specifications.
The servo accepts 4.8–8.4 V, uses PWM control and specifies a 333 Hz operating frequency. At 8.4 V, stall torque is 75 kg·cm and no-load speed is 0.091 s/60°; rated torque is 28 kg·cm. Stall torque cannot serve as a continuous-load rating, so selection must consider rated torque and duty cycle. The 1520 µs reference pulse differs from the 1500 µs position midpoint: confirm center and usable travel for the controller and delivered version. Commission unloaded or with limited load, and avoid sustained loading against mechanical stops.
Specifications
| Specification | Value & conditions |
|---|---|
| Model and purpose | AXR 9870 MG-D servo for model steering, control surfaces and mechanical actuation. |
| Operating voltage | 4.8–8.4 V |
| Performance at 4.8 V |
|
| Performance at 6 V |
|
| Performance at 7.4 V |
|
| Performance at 8.4 V |
|
| Rated torque | 28 kg·cm @ 8.4 VSupply voltage: 8.4 V. |
| Overall dimensions | 40 × 20 × 40.4 mm |
| Weight | 86 g |
| Motor type | Brushless motor |
| Gear material | Stainless steel gears |
| Bearing count | 2 |
| Cable length | 300 mm |
| Control signal | PWM |
| Operating frequency | 333 Hz |
| Reference pulse width | 1520 µs |
| Pulse width and corresponding angle | 500 / 1500 / 2500 µs → -90 / 0 / 90° |
| Center and travel qualification | The reference pulse is 1520 µs, while the position midpoint is 1500 µs. Confirm center and usable travel for the controller and delivered version. |
| Continuous-load limitation | Stall torque cannot serve as a continuous-load rating. Continuous-load selection must consider rated torque and duty cycle. |
| Supply range qualification | The voltage range defines permitted supply voltages; it does not imply test data at every voltage. |
| Mounting dimensions qualification | Drawings and specifications may use different dimensional references. Confirm the final mounting drawing and interface version before fabricating mounting parts. |
| Integration and commissioning | Check supply, signal pulse width, mounting holes and servo-arm connection. Confirm center, movement direction and mechanical travel before progressively checking the working load.Initial commissioning with the mechanism unloaded or its load limited. |
| Power and mechanical integration precautions | Allow supply headroom for transient current. Avoid cable voltage drop, reversed connections and sustained loading against mechanical stops. |
