CMU 3mm ID Hex Shaft Coupling 18mm Brass Motor-to-Wheel Connector

The CMU Hex Shaft Coupling 18mm x 3mm is a compact, precision-machined brass coupling designed to securely connect a 3mm DC gear motor shaft to a wheel, hub, pulley, or mechanical drive component. It provides a reliable and rigid mechanical link between motor and load, making it ideal for robotics, DIY electronics, RC projects, and small mechanical systems where accuracy and durability are essential.

Manufactured from solid brass, the coupling offers excellent strength, corrosion resistance, and long-term durability while remaining lightweight. The 3mm internal diameter ensures a snug, vibration-resistant fit on standard micro DC motor shafts, while the 18mm length provides stable alignment and strong torque transfer without adding unnecessary bulk to your build.

The coupling is supplied with two fixing screws (3×6mm and 4×8mm), allowing secure clamping of both the motor shaft and the connected component. Once tightened, the screws prevent slippage under load, ensuring efficient power transmission and smooth operation. The hex shaft design also improves grip and mechanical stability, reducing the risk of rotation loss during high-speed or high-torque applications.

This shaft coupling is perfect for:

• DC gear motors and micro motors
• Robotics and automation projects
• DIY vehicles and smart cars
• Motor-to-wheel or motor-to-pulley connections
• Educational electronics and engineering builds

Key Features

• Precision 3mm inner diameter for standard DC motor shafts
• 18mm length for stable and compact coupling
• Durable solid brass construction
• Secure fastening with included fixing screws
• Excellent torque transfer with minimal slippage
• Lightweight and corrosion-resistant

Specifications

• Material: Brass
• Inside Diameter: 3mm
• Total Length: 18mm
• Weight: 36g
• Screws Included: 3×6mm and 4×8mm (one of each)
• Application: Connecting DC gear motor shafts to wheels, hubs, or mechanical loads

The CMU 3mm Hex Shaft Coupling is a reliable, easy-to-install solution for creating strong, precise motor connections in compact mechanical and electronic projects.

What's in the box
1 x CMU 3mm ID Hex Shaft Coupling 18mm Brass Motor-to-Wheel Connector