KST CM509MG V6.0 HV Micro Servo – 6.0kgf.cm, 0.08 sec/60°

The KST CM509MG V6.0 HV Micro Servo is a compact, lightweight and high-performance digital servo designed for small-scale RC aircraft, lightweight models and RC cars.

Despite weighing only 15 grams and measuring just 23 × 11 × 24mm, the CM509MG delivers up to 6.0kgf.cm of torque at 8.4V with an impressive 0.08 sec/60° response speed.

Its combination of a coreless motor, metal gears, dual ball bearings and CNC aluminum alloy housing provides excellent precision, durability and performance in a very compact package.

The CM509MG is an excellent choice when you need more power than a conventional micro servo, but still want to keep the installation compact and lightweight.

Compact Size with Impressive Power

The CM509MG is designed for models where both weight and installation space matter.

At only 11mm wide and approximately 15g, it can be installed in compact areas where a conventional standard-size servo would be too large.

At the same time, its 6.0kgf.cm torque at 8.4V provides considerably more power than many lightweight micro servos.

This makes it ideal for:

• Small-scale RC aircraft

• Lightweight aerobatic models

• Small electric airplanes

• Gliders

• Lightweight control surfaces

• RC cars

• Compact RC models

• Applications where servo weight is critical

Fast 0.08 sec Response

The CM509MG combines its compact size with excellent speed.

At 8.4V, it reaches 0.08 sec/60°, providing fast and precise control response.

Performance across the operating voltage range:

• 3.6kgf.cm / 0.13 sec/60° @ 4.8V

• 4.8kgf.cm / 0.11 sec/60° @ 6.0V

• 5.5kgf.cm / 0.09 sec/60° @ 7.4V

• 6.0kgf.cm / 0.08 sec/60° @ 8.4V

This makes the CM509MG particularly suitable for small aircraft where fast and accurate control is important.

Coreless Motor

The CM509MG uses a coreless DC motor designed for fast response and smooth operation.

The coreless motor helps provide quick acceleration and precise positioning while keeping the servo compact and lightweight.

Combined with digital electronics, the motor provides responsive control for demanding small-scale RC applications.

Metal Gear Train

The servo features a durable metal gear train designed to handle the loads associated with small RC aircraft and other demanding applications.

The output shaft is supported by two ball bearings, helping to provide smooth operation, good centering accuracy and reliable mechanical performance.

The output shaft is made from AI7075 aluminum alloy, further reducing weight while maintaining strength.

CNC Aluminum Alloy Housing

The CM509MG uses an aluminum alloy housing that provides excellent rigidity and helps dissipate heat during operation.

The compact 23 × 11 × 24mm case makes the servo particularly easy to install in small wings, fuselages and other space-restricted applications.

At approximately 15g, it also helps keep the overall aircraft weight under control.

High-Voltage Compatible

The CM509MG V6.0 supports a wide 4.8–8.4V operating range.

At 7.4V, it already delivers 5.5kgf.cm of torque and 0.09 sec/60° speed, while 8.4V provides the maximum 6.0kgf.cm and 0.08 sec/60° performance.

This makes the servo compatible with modern HV receiver systems when operated within the specified voltage range.

Programmable Digital Electronics

The CM509MG features programmable digital electronics and programmable soft start.

This allows the servo characteristics to be configured to suit different RC applications using compatible KST programming equipment.

The default operating frequency is 1520μs / 333Hz.

Ideal for Small RC Aircraft

The CM509MG is particularly well suited to small and lightweight RC aircraft.

Recommended applications include:

• Small aerobatic RC planes

• Lightweight 3D models

• Small electric aircraft

• Gliders

• Small-scale sport models

• Lightweight control surfaces

• RC cars

Its combination of 6kgf.cm torque, 0.08 sec speed and only 15g weight makes it an excellent performance upgrade over conventional micro servos.

Key Features

• 6.0kgf.cm maximum torque @ 8.4V

• 0.08 sec/60° speed @ 8.4V

• Only 15g ±10%

• Compact 11mm-wide housing

• Coreless DC motor

• Durable metal gears

• Dual ball bearings

• AI7075 aluminum alloy output shaft

• Aluminum alloy case

• 4.8–8.4V operating voltage

• Programmable digital electronics

• Programmable soft start

• 25T / 5mm output spline

• Ideal for small-scale RC aircraft and lightweight models

Technical Specifications

Specifications are based on KST's technical specification and current product listings.

Package Contents

• 1 × KST CM509MG V6.0 HV Micro Servo

• 1 × Servo Accessory Set

Recommended Application

The CM509MG is designed for small-scale and lightweight RC applications. Always ensure that the servo torque is suitable for the control-surface loads of your particular model.

When operating at 7.4V or 8.4V, make sure your receiver and power system are compatible with the selected voltage.

KST CM509MG V6.0 – Small Size. Serious Performance.

The KST CM509MG V6.0 delivers an impressive 6.0kgf.cm of torque and 0.08 sec/60° speed at 8.4V while weighing only 15 grams.

With its coreless motor, metal gears, dual ball bearings and compact 11mm-wide housing, it is an excellent choice for small-scale RC aircraft, lightweight aerobatic models and other applications where performance, weight and installation space all matter.