KST MS825 V8.0 HV Brushless Servo – 35kgf.cm Contactless Hall Sensor

The KST MS825 V8.0 HV Brushless Servo is a high-performance standard-size servo designed for demanding large-scale RC aircraft, scale models and aerobatic airplanes.

With up to 35kgf.cm of torque at 8.4V and an impressive 0.11 sec/60° response speed, the MS825 combines high power with fast and precise control.

One of its key advantages is the contactless Hall-effect position sensor. Unlike conventional potentiometer-based servos, the contactless sensor eliminates physical contact at the position-sensing element, providing excellent precision, repeatability and long-term reliability.

Combined with a powerful brushless DC motor, hardened steel gears, dual ball bearings and a CNC aluminum alloy case, the MS825 V8.0 is built for serious RC aircraft applications.

High Torque and Fast Response

The KST MS825 V8.0 delivers an impressive combination of torque and speed.

At 8.4V, it produces 35kgf.cm of stall torque while achieving a fast 0.11 sec/60° no-load speed.

This makes it suitable for large control surfaces where both strong holding power and fast response are important.

The performance increases with higher operating voltage:

• 25kgf.cm / 0.15 sec/60° @ 6.0V

• 30kgf.cm / 0.13 sec/60° @ 7.4V

• 35kgf.cm / 0.11 sec/60° @ 8.4V

Contactless Hall Sensor Technology

The MS825 V8.0 uses a contactless Hall-effect position sensor instead of a conventional mechanical potentiometer.

This technology provides highly accurate position feedback without physical wear at the sensing element. The result is excellent centering accuracy, repeatability and long-term reliability, particularly valuable in large RC aircraft where vibration can be significant.

The contactless sensor is especially beneficial for large-scale scale and aerobatic models, where precise and consistent control-surface positioning is essential.

Powerful Brushless Motor

The MS825 is powered by a high-performance brushless DC motor.

Brushless technology provides fast response, smooth operation and excellent durability, making it well suited to demanding RC applications.

The combination of brushless motor technology and high-speed digital electronics allows the MS825 to respond quickly to control inputs while maintaining accurate positioning.

Hardened Steel Gear Train

For maximum durability, the MS825 V8.0 uses a robust hardened steel gear train.

The all-metal gear system is designed to withstand the high loads generated by large control surfaces and demanding flight conditions.

Combined with dual ball bearings, the gear train provides smooth operation and helps maintain precise control under load.

CNC Aluminum Alloy Case

The MS825 features a rigid CNC aluminum alloy case that provides excellent structural strength while helping to dissipate heat during operation.

Despite its high torque output, the servo maintains a compact standard-size footprint of just 40.5 × 20 × 38mm, making it easy to install in many large RC aircraft.

Programmable HV Servo

The MS825 V8.0 supports a wide 6.0–8.4V operating voltage range and is fully programmable.

Its programmable electronics allow the servo characteristics to be configured to suit different aircraft and control-surface applications.

The servo also features programmable soft start, helping to reduce sudden mechanical loads when the servo system is powered on.

Programming is supported using compatible KST programming tools.

Ideal for Large-Scale RC Aircraft

The MS825 V8.0 is an excellent choice for:

• Large-scale RC airplanes

• Scale aircraft

• Warbirds

• Large aerobatic models

• Giant-scale aircraft

• Large Extra and Edge models

• Large control surfaces

• Ailerons, elevators and rudders

• High-load flaps

• Other demanding RC applications

Its combination of 35kgf.cm torque, 0.11 sec speed, contactless Hall sensor and hardened steel gears makes it a particularly strong option for large aircraft where precision and reliability are important.

Key Features

• 35kgf.cm maximum torque @ 8.4V

• 0.11 sec/60° speed @ 8.4V

• Contactless Hall-effect position sensor

• High-performance brushless DC motor

• Durable hardened steel gears

• Dual ball bearings

• CNC aluminum alloy case

• High-voltage operation from 6.0V to 8.4V

• Fully programmable digital electronics

• Programmable soft start

• Standard-size servo dimensions

• Excellent centering accuracy and repeatability

• Designed for large-scale RC aircraft

Technical Specifications

The above values are based on KST's technical specification; the official sheet lists 35kgf.cm at 8.4V, 0.11 sec/60°, contactless positioning, brushless motor, hardened steel gears, 2BB and the 40.5 × 20 × 38mm case.

Package Contents

• 1 × KST MS825 V8.0 HV Brushless Servo

• 1 × Servo Accessory Set

Recommended Application

The MS825 V8.0 should be used with a suitable HV receiver and power system capable of supplying sufficient current for the servo and the complete aircraft.

For large aircraft equipped with multiple high-torque servos, always ensure that the receiver power supply, wiring and BEC are appropriately rated for the expected current demand.

KST MS825 V8.0 – Precision, Speed and High Torque

The KST MS825 V8.0 is designed for pilots who demand more from their servos. With 35kgf.cm of torque, 0.11 sec/60° speed, a brushless motor, hardened steel gears and a contactless Hall sensor, it delivers the precision, speed and durability required for demanding large-scale RC aircraft.