5-Axis CNC Machining of a High-Performance Propeller from Nibral

Summary

The client required a highly accurate and efficient propeller for a new class of performance yacht. The complex blade geometry could not be achieved with traditional casting and grinding methods. We used simultaneous 5-axis CNC milling to machine the entire propeller from a single Nibral (Nickel Bronze Aluminum) casting, resulting in a perfectly balanced and hydrodynamically optimized propeller.

The Challenge

Initial Need:

To maximize speed and fuel efficiency, the client's design featured complex, variable-pitch blades with extremely specific hydrodynamic profiles. Any deviation from the CAD model would cause vibration and cavitation, hurting performance.

Pain Points:

Traditional sand-casting followed by manual grinding and polishing is notoriously inaccurate. It's impossible to make two propellers exactly alike, and the final shape never perfectly matches the design, leading to unpredictable performance.

Our Solution

Final Summary:

A near-net-shape Nibral blank was cast, then mounted in our large 5-axis gantry mill. A specialized CAM program was created to generate the smooth, flowing toolpaths required for the complex blade surfaces. The result was a propeller with exceptional geometric accuracy (ISO 484/2 Class S), requiring only minimal polishing.

Outcome

Project Details