4mm Wheel Connector / DC Gear Motor Hex Coupling with Screws

4mm Hex Coupling for Robot Smart Car Wheel – Brass – 18mm Length

The coupling used in this design provides a stable connection between the motor and wheel, making it highly effective in builds that require a precise 4mm shaft coupling. Because of its strong brass construction, this part performs well in educational robots and DIY setups where a reliable wheel coupling is essential. Additionally, users working on robotics frequently choose this motor coupling for smooth torque transfer and long-lasting performance. Its robust machining ensures the 4mm shaft coupling maintains tight alignment during rotation, which helps improve durability in small chassis systems. Makers building smart cars or STEM robots benefit from this wheel coupling, as it keeps the wheel hub securely positioned. Furthermore, the structure enables the motor coupling to operate without frequent maintenance. Because it connects directly to DC geared motors, the 4mm shaft coupling becomes a dependable choice for compact robotic platforms. Students and hobbyists also appreciate how this wheel coupling supports stable motor output while keeping vibrations low. As a result, the motor coupling remains ideal for various automation and prototype tasks.

Technical Details

• Item Type: Coupling / Shaft Connector
• Material: Brass
• Inner Diameter (Motor Side): 4 mm
• Outer Hex Diameter: 12 mm
• Thread Size (Top): M4
• Body Length: 12 mm
• Hex Height: 6 mm
• Total Length: 18 mm
• Weight: 14 g
• Set Screw Type: M3 Grub Screw

Features

• High-strength brass construction for superior durability.
• Hexagonal outer design ensures secure wheel attachment.
• Compact 18mm size suitable for small robotic assemblies.
• Easy to install and requires no special maintenance.
• Transfers motor torque smoothly to the wheel hub.

Applications

• Smart car and robot wheel coupling
• DIY and educational robotics projects
• Automation and mini vehicle prototypes
• Motor-to-wheel power transmission systems

Physical Attributes

• Color: Golden (Brass Finish)
• Material: Brass
• Shape: Hexagonal
• Compatible Motor Shafts: 4mm diameter (Johnson Motor, BO Motor, Encoder Motor)
• Operating Torque Range: Suitable for low-power DC geared motors

Package Includes

• 1 × 4mm Hex Coupling – Brass – Short Type – 18mm Length