Seldom use the G68 cycle because it is such a pain to get it running right. I had one that bored one diameter that worked. Program had been sent back from lathe so I know nothing is wrong with it. I modified it to run a slightly more complicated bore. Only way I can get it to run is by making P7 = K0. If I leave stock for finishing (such as P7 = K.005), it alarms out with the 004 alarm. Makes no sense to me.
N10 G0 (G68 CYCLE)
N20 G97 S2000 M3
N30 X -.95 Z1. T08.08
N40 G92 S2000
N50 G96 S500
N60 Z.02 F.003
N70 G68 P0 = K -2.75 P1 = K0 P5 = K.02 P7 = K0 P8 = K.001 P9 = K.003 P10 = K1 P13 = K110 P14 = K170
N80 G0 G97 Z.5 M5
N90 X0 Z0 T0.0
N100 M30
N110 X -2.75 Z -.21
N120 X -2.17 Z -.21
N130 X -2.164 Z -.212
N140 X -2.162 Z -.212
N150 G3 X -1.88 Z -.353 I0 K -.141
N160 G1 X -1.88 Z -.66
N170 X -.95 Z -.66
Don't worry about the shallow DOC and slow feedrate. I think this lathe is the one with a 1/2 HP motor. .03 DOC at F.004 stopped the spindle around 2.3 diameter.
Thanks.