Specialized Concentrated Focused
Machine coordinate system is a set of fixed right-hand coordinate system. Its coordinate origin is
always fixed with respect to a certain position on the machine tool. Therefore, at any time, a certain
point in space can be exclusively fixed by the machine coordinate system.
The machine coordinate system requires the machine available of the homing function, or this
concept will only appear in the software.
3.2.2. Workpiece Coordinate System
As a set of right-hand coordinate system for the programmer, workpiece coordinate system is
used in programming. To establish it, the programmer can select a given point on the workpiece as the
origin (also called program origin). The origin of workpiece coordinate system (namely the workpiece
origin) is fixed with respect to a certain point on the workpiece, while variable with respect to the
machine origin. The origin of workpiece coordinate system should be selected meeting such
conditions as simple programming, easy dimension conversion and small machining errors.
Workpiece offset corresponds to WCS G54, G55, G56, G57, G58 and G59. After the system is
opened, the default WCS is G54, and the relation between workpiece offset and machine coordinate
system is as shown in Fig. 3-2.
G54(X)
Machine
Origin
Workpiece
Origin
Workpiece
Limit of Axial Motion
Fig. 3-2 The relation between workpiece offset and machine coordinate system
One, two or several workpiece offsets can be used in one machining program. As shown in Fig.
3-3, three workpieces are installed on the worktable, so each workpiece has a workpiece origin
corresponding to the G code of workpiece coordinate system. To drill a hole on each of the workpiece,
with calculation depth as Z-0.14, the programming example is as follows.
Basic Concepts「11」
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