computer numerical control programming basics - Industrial Press

4. Dimension the part clearly so that its shape can be understood
without making mathematical calculations or guesses.
5. Define the part so that a computer numerical control cutter
path can be easily programmed.
Machine Zero Point
The machine zero point can be set by three methods—by the
operator, manually by a programmed absolute zero shift, or by
work coordinates, to suit the holding fixture or the part to be
machined.
MANUAL SETTING - The operator can use the MCU controls to
locate the spindle over the desired part zero and then set the X
and Y coordinate registers on the console to zero.
Stored zero shifts (G54...G59)
Programmed zero shift (G92)
R = Reference point (maximum travel of machine)
M = Machine zero point (X0,Y0,Z0) of machine coordinate system.
W = Part zero point workpiece coordinate system.
Under G54 ... G59 the actual machine coordinates of part
zero are stored in the stored zero offsets memory and
activated in the part program.
Under G92 the actual machine coordinates are inserted and
used on the G92 line of the part program.
Fig. 19 The relationship between the part zero and the machine system of coordinates.
(Deckel Maho, Inc.)
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