Hong Jun

A new hollowing process for rapid prototype models

A new method of hollowing rapid prototype models based on STL models and their cross‐sectional contours is presented to meet the demands of hollowed prototypes in casting and rapid prototype manufacturing. Offsetting along the Z‐axis and cross‐sectional contour offsetting are employed to perform the hollowing operation. The process performs two‐dimensional Boolean operations on the polygons made by the offset contours of cross‐sectional contours instead of three‐dimensional offsetting of the STL models. This hollowing operation is especially suitable for hollowing STL models with free‐form surfaces. Detailed algorithms are described to generate the correct offset contours of an STL model. Adopting this method, the hollowing process is dramatically simplified and becomes more efficient. This method has been verified by practical case studies, and it is proved that this simplified hollowing operation can reduce the prototype build time and cost.

A cross-sectional image measuring system based on NC milling machine

It is especially difficult to capture both exterior and interior shape data of a complex part with high accuracy and low cost by using the current reverse engineering measuring methods. This paper presents a novel cross-sectional imaging measurement system for reverse engineering based on existing NC milling machine, which can simultaneously acquire the full cross-sectional contours of a part with complex external and internal surfaces. The principle and architecture of the system are described. Furthermore, some key issues to implement the measuring system are discussed in detail. Finally, a real case is employed to illustrate the applications of the system. As a result, this system provides a feasible and useful scheme for many enterprises to construct their own reverse measuring system based on existing equipments to aid rapid product development and extend the function of existing equipments. It will potentially find widespread application in industrial reverse measurement due to its advantages including high accuracy, rapid construction and low cost.