Machining center is more common in application than drilling and tapping center machine, it is mainly used for processing plane, curved surface and other shapes of equipment. The drilling and tapping center is mainly used for drilling and tapping, the current market to do mobile phone shell will use a lot of this machine, generally its processing volume is very large, customers are generally on dozens of sets at a time, the application is relatively single, unlike the milling machine grinder alone on one or two on the line, it is a quantity, a large amount. The machining center can be used for milling, but the machining center can only carry out slight milling, and can not carry out heavy load machining. In the selection of tool store, the machining center is mainly the hat tool store and the disk tool store, while the drilling and tapping center is mainly the turret tool store and the turret tool store. In terms of moving speed, the drilling and tapping center adopts linear guide rail, which is faster than the machining center, and the machining efficiency of the machine tool is obvious.

The problem that the machining center often has in processing should be noted is over-cutting, and when the inner contour arc machining, if the selected tool radius rD is too large, it is likely to produce over-cutting when it exceeds the required arc radius R. The NC machining program is programmed according to the actual contour track of the workpiece, without considering the motion track of the tool in the actual machining process. Otherwise the workpiece overcutting will be inevitable. Due to the existence of the tool radius, the actual tool trajectory becomes thick and does not coincide with the programming trajectory. In order to obtain the correct workpiece surface profile, the tool trajectory and the programming trajectory must be set with the tool radius compensation instruction.