Implementation of the process chain from point data acquisition to rapid tooling of a ship propeller

摘要

In the ship building industry, it is often required to manufacture complex shapes such as propellers for the development of a new ship propulsion system. Since these are obliged to a number of changes in the course of optimization process, several propeller prototypes have to be manufactured during the development stage. A conventional manufacturing technology used in industry for the manufacture of ship propellers is the 5-axis milling. Due to the complexity of the process, however, it is often difficult to generate the NC toolpath which has additionally to be tested by simulation before milling.rnIn this paper, an alternative way of manufacturing functional prototypes of propellers is investigated by using reverse engineering and rapid tooling techniques. The surface of an existing ship propeller was measured by a tactile measuring system and the point data of the surface acquired were used for modeling of a solid model in CAD system. By using LOM and casting processes, an aluminum propeller for functional test was manufactured, and its accuracy was measured by a laser scanner and compared with the original CAD data. The economics of rapid tooling compared with 5 axis milling in terms of processing time and cost was also investigated which is of importance when a new investment of rapid tooling is considered.