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Technical Specifications
Last Updated: 2026-10-25
Weight
Dimensions
Torque
Speed
Current
Temp
Wire
| Identity | |
| Brand |  |
| Product Number | BMS-391HT |
| Category | Hobby |
| Performance | |
| Torque |
8.4V
134.73 oz-in
9.70 kg-cm
1.0 N-m
7.4V
119.45 oz-in
8.60 kg-cm
0.8 N-m
6.0V
95.84 oz-in
6.90 kg-cm
0.7 N-m
|
| Speed |
8.4V
0.10 sec/60°
600.0 deg/s
100.0 RPM
7.4V
0.11 sec/60°
545.5 deg/s
90.9 RPM
6.0V
0.13 sec/60°
461.5 deg/s
76.9 RPM
|
| Physical | |
| Weight | 0.78 oz22.0 gAverage |
| Dimensions |
L 1.142 in W 0.512 in H 1.181 in L 29.0 mm W 13.0 mm H 30.0 mm |
| Case Material | Aluminum |
| Drivetrain | |
| Motor Type | Coreless |
| Gears | Metal |
| Gear Spline/Teeth | 25 T |
| Rotation/Support | Dual Bearings |
| Control & Signal | |
| Modulation | Digital |
| Neutral Position | 1500 µs |
| Dead Band | 1 µs |
| Refresh Rate | 333 Hz |
| Control System | PWM |
| Electrical & Environment | |
| Operating Voltage | 4.5–8.5 V |
| Connectivity | |
| Connector | JR (Universal) estimate |
| Origin | |
| Country of Origin | Taiwan |
Disclaimer: Most data is sourced from the manufacturer. Some data is sourced from our loyal community and with the help of AI. We aim for accuracy but are not responsible for inaccurate information.
Class Comparison
| Weight | Average Lighter than 64% of 505 Digital Mini servos |
Performance Analysis
| Shaft Power | 1.36–2.49 W |
| Power Density | 3.608 W/in³ More power-dense than 76% of 482 Digital Mini servos |
| Torque Density | 4.3564 oz-in/g |
| Torque-to-Volume Ratio | 138.79 oz-in/in³ |
| Speed-to-Weight | 0.34965 (1/sec·g) |
| Speed-Torque Trade-off | 12.46 |
| Voltage Range Width | 4.0 V Wider voltage range than 91% of 405 Digital Mini servos |
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Reviews (1)
Includes 1 review aggregated from around the web.
There are very few reviews for this servo on the web. A German forum member calls it his absolute favorite 13mm servo thanks to its low play.
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