G88 - Bore: Feed In, Spindle Stop, Feed Out, Spindle Start

Bore Cycle with feed in, spindle stop, feed out and spindle start at top.

The G88 bore cycle initiates boring operation at defined XY position at defined height and for defined depth. G88 cycle can be repeated at any given XY position until cycle is cancelled with G80 or with any other motion command(G01/G00).

Single boring operation can be divided into following phases:

Phase 1: Spindle
If spindle is OFF prior cycle execution, software will return error.

If spindle is ON, spindle speed is set with pre-existing S value.

Phase 2: XY position
The boring XY position is determined by the active distance mode and optional XY parameters.

When the cycle code does not include optional XY parameters, the boring process will occur at the current machine position. This applies regardless of whether the active distance mode is G90 or G91.

If G90 is active and the cycle code includes XY parameters, the boring process will take place at the position specified by the XY parameters.

If G91 is active and the cycle code includes XY parameters, the boring process will take place at the position defined by the XY parameters, taking into account the G91 distance mode.

Phase 3: R level
R level is Z height where boring starts. R level is set with parameter R. Machine Z axis travels to R plane at traverse speed.

Phase 4: Plunge to bottom Z
From R plane machine descends to bottom Z level, defined with parameter Z. If cycle uses F parameter, machine travels to bottom Z level at set F speed. If cycle does not use F parameter value, machine travels to bottom Z level at F speed set prior of cycle execution.

Phase 5: Bottom Z, dwell, spindle stop and retract
Once machine reaches bottom Z level position, and if P parameter is used, it dwells for a set period of time and stops spindle. From bottom height machine retracts to retract height at feed speed.

Retract height is defined with G98/G99, which can be either R plane or init height value.

If G98 is active, retract height is init height.

If G99 is active, retract height is R plane.

Phase 6: Spindle start
Start spindle.

G88 <X> <Y> R Z <P> <F> 

G00 X0 Y0 Z10
M3 S750
G98 G88 X0 Y0 R0 Z-15 P0.5 F500
X10
X20
X30
M5

G85, G86, G87, G89