148 7 Programming: Canned Cycles, sub-programs
7.2 Canned Cycles
Drilling Cycles
Drilling, Tapping, and Boring
When you activate a drilling cycle, it executes after each programmed
position, until you cancel it.
The following reminders are for drill cycles:
F feedrate is optional. If it is not given, the current feedrate is used.
All start heights (R) and finish heights (P) as well as Z dimensions are
absolute dimensions.
For all peck drill cycles, R (start height) must be 0.1" (or 2 mm) above
the work surface.
Tapping uses S word for Spindle Yes/No. Your machine must be
equipped with spindle M-functions.
Z-axis depth can be changed by placing a new Z depth on the same
line as the X- and/or Y-axis location of the hole you want the new
depth applied. A Z address on a line of its own causes the control to
drill the new depth at the current location.
Basic Drill Cycle
Modal cycles remain active until canceled. Use Drilloff (G80) to cancel
drill, tap, and bore canned cycles.
Basic drilling cycle is generally used for center drilling or hole drilling
that does not require a pecking motion. It feeds from the start height
(R) to the specified hole depth (Z) at a given feedrate (F), then rapids
to the return height (P).
G-code format: G81
The P entry (return height) is optional, and you do not need
to provide it. If you do not specify P, the CNC sets it to R.
If P is provided, it must be greater than R, or an alarm is
given.
Field Code Description
ZDepth Z Absolute hole depth. (Required)
StartHgt R Initial Z start point, in rapid. (Required)
ReturnHgt P Z return point after hole depth, in rapid.
Feed F Feedrate