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When your motion system demands consistent belt tracking and slip-free power transfer, a mismatched or poorly machined pulley becomes the weakest link. These V grooved aluminum pulleys are engineered for builders, robotics enthusiasts, and CNC hobbyists who need reliable, repeatable performance from their round belt drive systems.
Each pulley is machined from aluminum alloy with a V-profile groove sized for 7mm round belts. Available in single-groove and double-groove configurations, outer diameters range from 20mm to 100mm (~0.79" to ~3.94"), with a consistent 7mm bore across all variants. The double-groove option allows parallel belt runs or two-stage drive setups without additional hardware.
Typical applications include desktop CNC router axis drives, 3D printer filament feed mechanisms, lightweight conveyor belt systems, and custom robotics joint actuators — anywhere a compact, low-backlash round belt pulley for 7mm belt is needed.
| Material | Aluminum alloy |
|---|---|
| Groove Type | V-groove |
| Belt Compatibility | 7mm round belt |
| Bore Diameter | 7mm |
| Outer Diameter (OD) | 20mm – 100mm (0.79" – 3.94") |
| Groove Configuration | Single groove / Double groove (see variant options) |
| Finish | See variant options |
| Weight | See variant options |
| Packing Quantity | 1 piece per order (multi-pack options available) |
The outer diameter (OD) determines your drive ratio when paired with a second pulley. Divide the driven pulley OD by the driving pulley OD to get the speed reduction ratio. For example, a 20mm driving pulley paired with a 60mm driven pulley gives a 3:1 reduction. Select OD based on your target RPM and torque requirements.
Single-groove pulleys carry one 7mm round belt and are used in standard single-belt drive configurations. Double-groove pulleys have two parallel V-grooves, allowing two belts to run side by side — useful for higher torque transmission, redundancy, or two-stage compound drive ratios without adding extra shaft components.
The bore diameter is 7mm across all variants. If your shaft is exactly 7mm, the pulley should slide onto the shaft. For a secure, non-slip fit, a set screw, keyway, or retaining collar is recommended depending on your torque load. Confirm your shaft diameter before ordering.
Aluminum alloy pulleys are well-suited for light-to-medium duty applications such as 3D printers, desktop CNC routers, robotics, and small conveyor systems. For heavy industrial loads or high-impact environments, consider whether a steel pulley would be more appropriate. For most DIY and maker applications, aluminum provides an excellent balance of strength and low rotational inertia.
Aluminum naturally forms a thin oxide layer that provides moderate corrosion resistance in typical indoor environments. These pulleys are suitable for dry and low-humidity conditions. For outdoor or high-moisture environments, consider applying a protective coating or anodizing treatment after purchase.
The V-groove profile is compatible with both solid round belts and O-ring style round belts with a 7mm cross-section diameter. Ensure the belt's cross-section matches the groove profile for proper seating and tracking. Using an undersized or oversized belt may cause slipping or premature wear.
If you are building a single-axis drive, one pulley is typically sufficient. For multi-axis CNC machines, conveyor systems, or robotics with multiple joints, ordering the required quantity upfront ensures consistent batch quality and avoids delays. The packing quantity option on this listing is set to 1 piece per unit — add the quantity you need to your cart.
