Does the wire guide really improve the accuracy of edm machines?

      It is well known that the low speed wire cut edm machines are equipped with gemstone guides or diamond guide in the upper and lower wire guide devices, and the diamond guide plays a key role in improving the edm machining precision. As the wire walking speed of the low speed wire cut edm machine is quite slower than high speed edm machines, and the wire material is copper, the hardness is low, so the electrode wire on the wire guide wears less out. Brass wire is the very electrode wire used in the low speed wire cut edm machines. Besides, the copper stress is very small and easily to be straightened, so the electrode wire, brass wire is easier to thread through wire guide by man-made (or automatically). However, the situation in the medium speed wire cutting machine is very different. The electrode wire for MS-WEDM is the molybdenum wire. The hardness and stress are far greater than the copper wire. 

      When you observe molybdenum wire under the microscope, the surface of molybdenum wire has a large number of "tumor". The high-speed operation of the molybdenum wire on the guide is no different from the "wire saw". So the abrasion of wire guide is very heavy compared with the low speed wire cut edm machines, and it is difficult to overlap the molybdenum wire between the orifice of the guide and the upper and lower guide wheels when the guide is mounted. This not only speeds up the wear and tear of wire guide, but also directly affects the position of the molybdenum wire during cutting production. This is very fatal to the position accuracy of the working mold and the consistency of the same parts. In addition, due to the large internal stress of the molybdenum wire, and the small hole of wire guide can only be directly 0.01mm larger than the molybdenum wire (otherwise no guide effect), and wire guide and molybdenum wire are sticky with working fluid, so it is very difficult when the operator need to make molybdenum wire thread through the small hole. It's also a huge test to operator’s patience. From the edm machining practical operation, most customers eventually give up the application of the wire guide. But we need to pay more attention to the usage of wire guide and edm filters.