CNC machine tool machining centers are often divided into vertical machining centers, horizontal machining centers, gantry machining centers, and universal machining centers according to the state of the spindle in space. The spindle of the machining center is called a vertical machining center in a vertical state in space, and the horizontal machining center is called a horizontal machining center in which the spindle is in a horizontal state in space.

              Vertical machining center: the structural form is mostly fixed column type, and the workbench is rectangular, suitable for processing disk, sleeve and plate parts. Vertical machining centers usually have three linear motion coordinates, XYZ axis, and a fourth axis A axis can be installed on the table.

              The vertical machining center is easy to clamp, easy to operate, easy to observe the processing situation, and convenient to debug the program, but due to the influence of the height of the column and the tool change mechanism, it cannot process parts that are too high. The vertical machining center has a simple structure, a small footprint and a low price.

              Horizontal machining center: usually adopts a movable column, and the headstock moves up and down along the guide rail between the two columns. Horizontal machining centers usually have three linear motion coordinates, facing the machine tool, moving left and right is the X axis, moving back and forth is the Z axis, and moving up and down is the Y axis. Horizontal machining centers can also have a fourth axis, the A-axis, mounted on the table. Parts such as helical cylindrical cams can be processed. The horizontal machining center is inconvenient to observe when debugging the program and try to cut pins, it is inconvenient to monitor during processing, and it is inconvenient to clamp and measure parts, but it is easy to remove chips during processing. Compared with the vertical machining center, the horizontal machining center has a complex structure, occupies a large area and is expensive.

              Gantry machining center: Most of its spindles are vertically set, with ATC system and replaceable spindle head attachments. The system software has many functions and can be used for multiple purposes. It is suitable for processing large parts.

              Universal machining center: The universal machining center is a five-sided machining center, which has the functions of a vertical machining center and a horizontal machining center. After the workpiece is clamped once, it can complete the machining of all sides and top surfaces except the mounting surface.

Common universal machining centers are:

1. The spindle can be rotated 90°, it can work like a vertical machining center or a horizontal machining center.

2. The spindle does not change direction, and the worktable rotates 90° with the workpiece to complete the processing of five surfaces.