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Technical Specifications
Last Updated: 2026-10-25
Weight
Dimensions
Torque
Speed
Current
Temp
Wire
| Identity | |
| Brand |  |
| Product Number | XQ-S4120D |
| Category | Hobby |
| Discontinued | Yes |
| Performance | |
| Torque |
8.5V
291.70 oz-in
21.00 kg-cm
2.1 N-m
7.4V
247.20 oz-in
17.80 kg-cm
1.7 N-m
Average
|
| Speed |
8.5V
0.14 sec/60°
428.6 deg/s
71.4 RPM
7.4V
0.16 sec/60°
375.0 deg/s
62.5 RPM
Average
|
| Running Current |
8.5V
0.150 A
150 mA
7.4V
0.240 A
240 mA
Average
|
| Stall Current | 2–2.3 A2000–2300 mAAbove Average |
| Physical | |
| Weight | 2.03 oz57.5 gAbove Average |
| Dimensions |
L 1.583 in W 0.791 in H 1.528 in L 40.2 mm W 20.1 mm H 38.8 mm |
| Case Material | Plastic / Aluminum |
| Drivetrain | |
| Motor Type | Coreless |
| Gears | Titanium |
| Gear Spline/Teeth | 25 T |
| Rotation Mode | Positional |
| Rotation/Support | Dual Bearings |
| Control & Signal | |
| Modulation | Digital |
| Direction | Counterclockwise |
| Rotational Range | 110° |
| Mechanical Limit | 210° |
| Pulse Width | 800-2200 µs |
| Neutral Position | 1500 µs |
| Dead Band | 2 µs |
| Control System | PWM |
| Electrical & Environment | |
| Operating Voltage | 7.4–8.5 V |
| Power Source | 2S LiPo |
| Temperature | -15–60 °C5–140 °F |
| Water Rating | Splashproof |
| Idle Current | 0.008 A8 mA |
| Connectivity | |
| Connector | JR (Universal) |
| Wire Length | 300 mm11.81 in |
| Origin | |
| Country of Origin | China |
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
| Torque | Average Stronger than 57% of 1060 Digital Standard servos at 7.4V |
| Speed | Average Faster than 36% of 1045 Digital Standard servos at 7.4V |
| Weight | Above Average Lighter than 68% of 1880 Digital Standard servos |
| Running Current | Average Lower draw than 47% of 226 Digital Standard servos at 7.4V |
| Stall Current | Above Average Lower draw than 82% of 570 Digital Standard servos |
Performance Analysis
| Shaft Power | 2.86–3.85 W |
| Power Density | 2.014 W/in³ More power-dense than 44% of 1768 Digital Standard servos |
| Torque Density | 4.2991 oz-in/g Stronger than 67% of 1053 Digital Standard servos |
| Torque-to-Volume Ratio | 129.20 oz-in/in³ Denser torque than 58% of 1058 Digital Standard servos |
| Speed-to-Weight | 0.10870 (1/sec·g) Faster than 46% of 1038 Digital Standard servos |
| Speed-Torque Trade-off | 39.55 Better balanced than 63% of 1034 Digital Standard servos |
| Current-per-Torque Ratio | 0.0093 A/oz-in More efficient than 84% of 331 Digital Standard servos |
| Idle-to-Running Current Ratio | 0.033 Lower idle draw than 69% of 167 Digital Standard servos |
| No-Load vs Stall Current Spread | 9.58 Narrower current spread than 75% of 179 Digital Standard servos |
| Torque Gain per Volt | 16.37%/V More voltage-responsive (torque) than 55% of 873 Digital Standard servos |
| Speed Gain per Volt | 12.99%/V More voltage-responsive (speed) than 34% of 874 Digital Standard servos |
| Voltage Range Width | 1.1 V Wider voltage range than 4% of 1560 Digital Standard servos |
| Dead-Band-to-Pulse-Width Ratio | 0.0014 Finer dead band than 57% of 504 Digital Standard servos |
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Reviews (1)
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WOLF
November 1, 2012Application(s): STEERING 1/8 ROCK CRAWLER STEERING 1/10 DRIFT RACER
Comments: DO NOT BUY HAD 3 OF THESE ALL DEAD WITHIN 3 MONTHS ONLY AT 7.4VOLTS had no back up support from seller