MACH-1 RACING – M81SR 55 KG SR SERIES DIGITAL PROGRAMMABLE SERVO

MACH-1 SR SERIES 55KG – Programmable Digital Brushless Servo

Built for serious performance, the MACH-1 SR Series 55KG digital programmable servo is engineered to deliver exceptional torque, precision, and reliability — making it a top choice for competitive 1:8 scale electric and nitro buggy and truggy drivers around the world.

This servo has proven itself at high-level international events including:

• 2024 Dirt Nitro Challenge

• 2024 Psycho Nitro Blast

• 2024 Silver State

• 2024 RCRA Queensland State Titles

• 2024 Philippines Masters
  …and many more regional events across Australia and the USA.

Highlights

• Programmable high-voltage digital servo

• CNC-machined 3-piece aluminum alloy case for superior heat dissipation and minimal flex

• Hardened stainless steel gears with reinforced pin for added strength

• Powerful 4-pole brushless motor, delivering up to 55KG stall torque

• Three dust-resistant ball bearings for smooth, durable operation

• Magnetic angle sensor ensures accurate performance even in high humidity

• Waterproof rating: IP67

• Compatible with 2S LiPo batteries and standard 25T output spline

Technical Specifications

• Working Voltage: 4.8V – 8.4V

• Speed:
    0.145 sec/60° @ 4.8V
    0.125 sec/60° @ 6.0V
    0.100 sec/60° @ 7.4V
    0.087 sec/60° @ 8.4V

• Stall Torque:
    36 kg-cm (500 oz-in) @ 4.8V
    43 kg-cm (597 oz-in) @ 6.0V
    48 kg-cm (667 oz-in) @ 7.4V
    55 kg-cm (750 oz-in) @ 8.4V

• Power Consumption (Unloaded):
    280mA @ 4.8V
    320mA @ 6.0V
    360mA @ 7.4V
    400mA @ 8.4V

• Power Consumption (Loaded):
    4600mA @ 4.8V
    5400mA @ 6.0V
    6200mA @ 7.4V
    7000mA @ 8.4V

• Dead Band: 2 µSec

• Signal Range: 500–2500 µSec

• Size: 40 × 20 × 38 mm

• Weight: 83 g

• Connector Wire: 300mm / 22AWG

• Gears: Hardened Steel

• Bearings: 3x Ball Bearings

• Angle Sensor: Magnetic