Lathe coordinate system is also called mechanical coordinate system. It is the reference coordinate system used by CNC for coordinate calculation and the inherent coordinate system of lathe. The point of origin of the lathe coordinate system is called the mechanical reference point or mechanical zero point. After power on, the lathe coordinate system is set by returning to the reference point. Once the lathe coordinate system is set, it will remain unchanged until the power is off. For lathes equipped with incremental encoders, the operation of returning to the reference point must be performed to set the lathe coordinate system after each power-on or power-off. For lathes equipped with multi-turn absolute encoders, it is not necessary to perform the reference point return operation after each power-on and power-off. For CNC lathes, it has 2 coordinate systems, namely X axis and Z axis.
The X axis is the front and back direction of the horizontal plane. It is centered on the main axis. The tool is far away from the spindle as positive, and the tool approaches the spindle as negative. The X axis is used to control the size of the workpiece.
The Z axis is the left and right direction of the horizontal plane, that is, the direction from the main shaft to the tailstock. The direction approaching to the spindle or workpiece is negative, and the approaching direction to the tailstock is positive. The Z axis controls the length of the workpiece.
As for types of CNC lathes, CNC lathes can be divided into front tool rest and rear tool post. Their distinction is centered on the spindle, the tool post in front of you is the front tool post, and the tool post behind the spindle is the rear tool post.
The coordinate system of the machining center is different from that of a lathe. 3-axis machining center: Z-axis is the upper and lower sides of the tool post, the lower side of the tool post is negative and the upper side is positive. When the X-axis is the working platform: The left and right movement facing you is the X axis, moving to the left is positive, moving to the right is negative. When the Y axis is the working platform: the front and back facing you is the Y axis.