Abstract: The electrode wire (wire tool) will wear down in wire cut electrical discharge machining with high speed (WEDM-HS), especially in machining large thickness spatial curved surface parts with an accessory three axes linkage numerical control device. In order to decrease the bad influence of machining precision, the main wire wear down factors and the bad influence for machining precision are analyzed. A wire wear down online detection device is designed. The NC module is improved on by the introduced compensation factor. An NC arithmetic which includes online compensation quantity is proposed. A motion program online composite post disposal module based on the programmable multi-axis motion controller (PMAC) is established, and an example for online compensation is given. Contrast machining tests for online compensation of wire tool in WEDM are carried out and the experimental results show that the bad influence of machining precision for the wire wear dramatically decreases and the online compensation module has a good validity. The module also gives a powerful support to enhance the productivity, save on raw and processed materials, and make the best of the electronic wire for machining high precision, high thickness, long distance parts in 2D WEDM-HS.

Key words: Electrode wire wear-down, Large thickness spatial curved surface, Online detection, Post disposal module, Wire cut electrical discharge maching