ACU-RITE CNC 3500i - Manual (Page 57)

ACU-RITE 3500i 31
2.1 F
undamentals of P
o
sitioning
Absolute and incremental work piece positions
Absolute work piece positions
Absolute coordinates are position coordinates that are referenced to
the datum of the coordinate system (origin). Each position on the work
piece is uniquely defined by its absolute coordinates.
Example 1: Holes dimensioned in absolute coordinates
Incremental work piece positions
Incremental coordinates are referenced to the last programmed
nominal position of the tool, which serves as the relative (imaginary)
datum. When you write a part program in incremental coordinates,
you thus program the tool to move by the distance between the
previous and the subsequent nominal positions. Incremental
coordinates are therefore also referred to as chain dimensions.
Example 2: Holes dimensioned in incremental coordinates
Absolute coordinates of hole 4
X = 10 mm
Y = 10 mm
Hole 1 Hole 2 Hole 3
X = 10 mm X = 30 mm X = 50 mm
Y = 10 mm Y = 20 mm Y = 30 mm
Hole 5 , with respect to 4 Hole 6 , with respect to 5
X = 20 mm X = 20 mm
Y = 10 mm Y = 10 mm