As well as ship models, we build models of propellers and rudders. The propellers are milled from metal and the rudders from hard foam. We also do 3D printing in plastic or metal.
The propeller design is provided by the client but can also be made by MARIN in the propeller workshop. A propeller comprises a shaft and 3 to 7 propeller blades which have very complex, double curved surfaces.
To mill a propeller blade we use a very fast en precise 5-axis milling machine. 5-axis means that the machine can reach any angle and does not need to be turned by hand.
To mill a propeller blade surface on a modern numerically controlled machine, surfaces specification are required. We use various computer programs for this purpose. The surface is input and the milling tool paths are projected on the surface. This enables the whole milling process to be monitored in a simulation program.
After the propeller blades have been milled, the finishing is inspected and the blades are polished. They are then mounted on the shaft and set in the required speed position. The leading edge of the propeller is checked with microscope. The geometry of the milled blade is checked against the required geometry.
Did you know
propellers that are now machine milled were once made by hand?