SV905-12 HV Brushless Metal Gear 17Kgf.cm 0.04sec Tail Servo for 550-700 Class RC Helicopters
KST SV905-12 HV Brushless Tail Servo
The KST SV905-12 HV Brushless Tail Servo is designed for 550–700 class RC helicopters, delivering the high-speed response, strong torque, and reliability required for demanding tail control applications.
Powered directly by a 12V LiPo battery, the SV905-12 provides up to 17Kgf.cm of torque at 13V with an ultra-fast 0.04 sec/60° speed, ensuring quick and precise tail response during high-performance flight.
Featuring a brushless motor, dual ball bearings, and a robust metal gear train, the servo delivers smooth, stable, and accurate operation with excellent durability under demanding conditions.
With its combination of high-voltage direct drive, powerful torque, and exceptional response speed, the SV905-12 is an excellent choice for pilots seeking precise and reliable tail control on 550–700 class RC helicopters.

Features
- DC 12V Rated Voltage
- Support 8–13V High Voltage or 2–3S LiPo Battery Direct Drive
- High Frequency & Fast Response
- Ultra High Torque & Excellent Speed
- Dual Ball Bearings
- Brushless DC Motor
- Hardened Steel Gear
- CNC Aluminium Case
- Programmable
- Ideal for 550–700 Class RC Helicopters Tail
Specification
| Parameter | Value |
| Item | SV905-12 Tail Servo |
| Rated Voltage | DC12.0V |
| Voltage Range | DC8.0V–13.0V |
| Torque | 13Kgf.cm@8.4V / 16Kgf.cm@12.0V / 17Kgf.cm@13.0V |
| Speed | 0.06sec/60°@8.4V / 0.045sec/60°@12.0V / 0.040sec/60°@13.0V |
| Working Frequency | 760μs/560Hz |
| Operating Temperature | -10℃ ~ +65℃ |
| Programmable | Yes |
| Case Material | Aluminium Alloy |
| Motor Type | Brushless DC Motor |
| Gear Set Material | Hardened Steel |
| Position Sensor | Potentiometer |
| Ball Bearing | 2BB |
| Case Dimensions | 40.5mm × 20mm × 38mm ±0.2mm |
| Weight | 70g ±10% |
Package Includes
- 1 * SV905-12 Servo
- 5 * Plastic Servo Horn
- 1 * Servo Horn Screw
- 4 * Grommet
- 4 * Eyelet
- 4 * Mounting Screw
