Analytical approach to offsetting and pocket milling

In this study, a new offsetting algorithm has been developed for pocket milling operations on CNC milling machines in order to generate tool paths without error and suitable for the pocket profile. In this algorithm, pocket milling properties are read from DXF database. Offset lines and arcs are calculated by analytical equations of items that formed the profile. Then, all of the items are trimmed at the intersection points of offset for simplifying unnecessary items. Inaccurate offset items are thrown away, which would cause incorrect tool paths and then offsetting operation is ended. The algorithm works with DXF files obtained from AutoCAD 2009 and is applied using Delphi 7 program. The developed offsetting algorithm has been approved in the different applications.Key Words: Offset, Feature recognition, Pocket milling, DXF