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Product Overview
The Aluminum Blue Small Coupling (L25×D14mm) from Pro Tronix is an essential hardware component for motion control systems. It is specifically designed to connect the output shaft of a NEMA 17 stepper motor (typically 5mm) to an 8mm lead screw (standard for Z-axis movement). Unlike flexible couplers that allow for misalignment, this rigid design provides a solid, direct connection, minimizing “backlash” and ensuring the highest possible accuracy for your mechanical projects.
Technical Specifications
| Feature | Specification |
| Material | Lightweight Anodized Aluminum |
| Color | Electric Blue |
| Length (L) | 25mm |
| Outer Diameter (D) | 14mm |
| Inner Diameter 1 | 5mm |
| Inner Diameter 2 | 8mm |
| Fastening Type | Set Screws (Grub Screws) |
| Supplier | Pro Tronix |
Key Features
Precision Machined: Bored to exact tolerances of 5mm and 8mm to ensure a snug fit and perfect alignment of the rotating axes.
Rigid Power Transfer: Zero flexibility means 100% of the motor’s torque is transferred to the lead screw, ideal for heavy-lift Z-axis applications.
Durable Anodized Finish: The blue coating doesn’t just look professional—it protects the aluminum from oxidation and wear.
Low Inertia: Its compact 14mm diameter and aluminum construction keep the rotational mass low, allowing for faster accelerations.
Common Applications
3D Printers: Connecting NEMA 17 motors to T8 lead screws for high-precision Z-axis movement.
CNC Routers: Coupling stepper motors to drive shafts in small-scale milling machines.
DIY Robotics: Connecting motor shafts to wheels or custom mechanical linkages.
Automation Rigs: Used in any system requiring a reliable 5mm to 8mm transition.
You can see the rest of our available 3D printing and CNC parts from here: 3D Printer & CNC | Pro Tronix
