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17 Canned Cycles for Drilling
17.1.13 Boring Cycle (Manual Operation on the Bottom Point) (G88)
Fig.
The variables used in the cycle are
G17 G88 Xp__ Yp__ Zp__ R__ P__ F__ L__
G18 G88 Zp__ Xp__ Yp__ R__ P__ F__ L__
G19 G88 Yp__ Zp__ Xp__ R__ P__ F__ L__
The spindle must be given rotation M3 when the cycle is started.
The operations of the cycle are
1.
2.-
3.
4.-
5.boring as far as the bottom point with feed F
6.– dwell with value P
–spindle stop (M5)
–the control assumes STOP state (M0), from which the operator can get in one of the manual movement modes (JOG, INCREMENTAL JOG, or HANDLE) and operate the machine manually, for example retract the tool from the side of the hole then remove the tool from the hole. After returning AUTO mode machining can be continued by START.
7.with G99, START followed by retraction to point R (rapid traverse)
8.with G99, spindle
9.with G98, rapid-traverse retraction to the initial point
10.with G98, spindle
The cycle is the same as case "A" of G87 but dwelling before the spindle stop.
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