[sinha_nsit]

Fanuc 0i manual says in G71 type II section:
"The offset of the tool tip radius is not added to finishing allowances. In turning, the offset of the tool tip radius is assumed to be zero."
Does it mean that radius compensation (G41/42) is not possible in type II turning? I have seen many people using radius compensation in type I turning. Please share your experience specially with regard to Fanuc controls.

[cogsman1]

I hG41/G42 in BOTH the type I & II. You just need to turn it on INSIDE the canned cycle and cancel it before you leave. Works fine on every machine I have ever tried it on. This will NOT work if you turn it on and then go into the G71/G72/G73 cycles.

[sinha_nsit]

Thanks a lot for extremely useful and exact information.
I still have a small doubt. Is radius compensation being taken care of by the subsequent G70 cycle after G71/72/73, or is it really being incorporated by G71/72/73. Without radius compensation, we will get slightly oversize job. So, even if G71/72/73 ignores radius compensation, the error would be corrected by G70. Just to test it, can you please run G71 without finishing allowances (i.e., without using G70), and measure the obtained dimensions. This will settle the issue exactly.

I have a book on macro programming by Peter Smid. He claims to have written this book for Fanuc Custom Macro B. In a programming example on page 211, he has used G42 before calling G71:
...
...
G00 Z3.0
G42 X51.0
G71 U2.5 R1.0
G71 P9 Q14 U1.5 W0.125 F0.3
N9 G00 X16.0
...
...
N14 X54.0 F0.3
G70 P9 Q14 S125
G00 G40 X100.0 Z50.0
...
...
In fact, I have seen several programs which use G42 before calling G71. I have a feeling that it is G70 which is using compensation, and not G71. Please clarify. I would be grateful. I am a teacher and I have to give exact information to my students.