Manual

154 7 Programming: Canned Cycles, sub-programs
7.2 Canned Cycles
Chip Break Cycle
 This is the chip-breaker peck-drilling cycle, generally used to
peck-drill medium to deep holes. The cycle feeds from the R-plane
to the first peck depth in Z, rapid retracts the chip-break increment
(W), feeds to the next calculated peck depth (initial peck less J), and
continues this sequence until it reaches a U depth, or until final hole
depth is reached. The peck distance is never more than I or less
than K.
 This cycle enables optimum drilling conditions for holes. For
maximum efficiency in deep hole drilling, set parameters to
accommodate the material and tool types used. Generally, the
deeper the hole, the smaller the peck distance (J). This prevents the
binding of chips, tool, and workpiece. Set U to retract the drill
completely at set depth intervals.
 G-code format: G87
Field Code Description
ZDepth Z Absolute hole depth. (Required)
MinPeck K Minimum peck distance (positive
dimension). Required.
StartHgt R Initial Z start point, in rapid. (Required)
PeckDecr J Amount to subtract from previous peck
(positive dimension). Required.
FirstPeck I First peck distance (positive dimension).
Required.
ReturnHgt P Z return point after hole depth, in rapid.
Retract
Dep
U Incremental depth between full retracts
(positive dimension).
ChipBrkInc W Chip break increment (positive dimension).
Feed F Feedrate