Aluminium U Pulley Single-Slot OD 30mm~100mm for Motor Machine 8MM PU Round Belt

The OD determines your drive ratio when paired with a second pulley. Divide the driven pulley OD by the drive pulley OD to get the speed reduction ratio. For example, a 30mm drive pulley paired with a 60mm driven pulley gives a 2:1 reduction. Select the OD that achieves your target RPM or torque output at the driven shaft.

Measure your motor or axle shaft diameter with a caliper before ordering. The bore hole must match the shaft diameter precisely — a loose fit causes runout and vibration, while an undersized bore cannot be mounted without machining. Available bore sizes range from 5mm to 32mm; select the OD × Bore variant that matches your shaft exactly.

This pulley's U-groove is sized specifically for 8mm PU round belts. Using a belt with a significantly different diameter may result in poor seating, reduced grip, and accelerated belt wear. For other belt profiles or widths, please verify groove dimensions match your belt cross-section before ordering.

Aluminium alloy pulleys are well-suited for light-to-medium duty motor applications typical of DIY automation, conveyor systems, and educational robotics. For heavy industrial loads or high-torque continuous-duty cycles, verify that the torque transmitted through the belt does not exceed the pulley's structural limits. If in doubt, contact us to confirm suitability for your specific load conditions.

Aluminium naturally forms a thin oxide layer that provides baseline corrosion resistance in typical indoor workshop and automation environments. It is not recommended for prolonged exposure to salt spray, strong acids, or alkaline solutions without additional protective coating. Surface finish details are listed per variant — contact us to confirm if a specific finish is required for your environment.

Set screw compatibility depends on the specific variant's hub design. Please review the product images for your selected OD × Bore size or contact us to confirm whether the variant includes a set screw hole. If a keyway is required for your application, please reach out before ordering to verify availability.

A smaller OD (e.g., 30mm) on the drive side increases output speed but reduces torque at the driven shaft. A larger OD (e.g., 100mm) on the drive side reduces output speed and increases torque. Choose based on whether your application is speed-critical (smaller drive pulley) or torque-critical (larger drive pulley). Pair with a driven pulley of the appropriate OD to achieve your target mechanical advantage.