Smithy CNC Mills - Manual (Page 110)

SmithyCNC Programmer’s Reference Manual: Mill Canned Cycles 10-7
2. a feed parallel to the Z-axis to (13,17, 4.2)
3. a traverse parallel to the Z-axis to (13,17,4.8)
Example 3 - Relative Position G81
Now suppose that you execute the first g81 block of code but from (0, 0, 0)
rather than from (1, 2, 3).
G90 G81 G98 X4 Y5 Z1.5 R2.8 Since OLD_Z is below the R value, it adds noth-
ing for the motion but since the initial value of Z is less than the value specified
in R, there will be an initial Z move during the preliminary moves.