NCT Group 99M, 2000M manual Fine Boring Cycle G76

17 Canned Cycles for Drilling

17.1.3 Fine Boring Cycle (G76)

Fig. 17.1.3-1

Cycle G76 is only applicable when the facility of spindle orientation is incorporated in the machine- tool. In this case parameter ORIENT1 is to be set to 1, otherwise message 3052 ERROR IN G76 is returned.

Since, on the bottom point, the cycle performs spindle orientation and recesses the tool from the surface with the values specified at I, J and K, the part will not be scratched when the tool is withdrawn.

The variables used in the cycle are

G17 G76 Xp__ Yp__ I__ J__ Zp__ R__ P__ F__ L__

G18 G76 Zp__ Xp__ K__ I__ Yp__ R__ P__ F__ L__

G19 G76 Yp__ Zp__ J__ K__ Xp__ R__ P__ F__ L__ Command M3 has to be issued prior to starting the cycle.

The operations of the cycle:

1.rapid-traverse positioning in the selected plane

2.-

3.rapid-traverse movement as far as point R

4.-

5.boring as far as the point Z, with feed F

6.– dwell with the value specified at address P

–spindle orientation (M19)

–rapid-traverse receding of the tool with values I, J, K in the selected plane

7.with G99, rapid-traverse retraction as far as point R

8.with G99,

–rapid-traverse retraction of the tool in the selected plane, opposite to the values specified at I, J, K

–spindle re-started in direction M3

9.with G98, rapid-traverse retraction to the initial point

10.with G98,

–rapid-traverse retraction of the tool in the selected plane, opposite to the values specified at I, J, K

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