Fanuc oi

[leszek0213]

Please i need help on pulley V groove cycle.
the machine show alarm G71-G76
N295G0X15.8
N300G0X15.8Z-0.806
N305G71U0.05R0.025
N310G71P315Q345U0.01W0.005F0.012
N315G1X13.9078F0.
N320Z-0.9669
N330X12.7264Z-1.1705
N335Z-1.3295
N345X13.9078Z-1.5331
N350G0X15.8

[txcncman]

G71 does not allow the diameter to reverse.

N295G0X15.8
N300G0X15.8Z-0.806
N305G71U0.05R0.025
N310G71P315Q345U0.01W0.005F0.012
N315G1X13.9078F0. (<<<smaller than X15.8 - OK)
N320Z-0.9669
N330X12.7264Z-1.1705 (<<<smaller than X13.907 - OK)
N335Z-1.3295
N345X13.9078Z-1.5331 (<<<larger than X12.7264 - NOT OK)
N350G0X15.8

[angelw]

G71 does not allow the diameter to reverse.

Not correct.

There are two versions of G71, Type I and Type II. Although Type II is an option, most machines are supplied with both versions. Type II was first introduced in the 6TB control.

G71 Type I only tolerates Monotonous direction X moves, whilst Type II profile need not show monotone increase or monotone decrease along the X axis, and can have up to 10 concave (pockets) forms.

To activate G71 Type I, only an X(U) move is specified in the first part shape description block referenced by P in the G71 block. Type II is activated by specifying both X(U) and Z(W) in the first block.

leszek0213's problem is that only X was specified in block N315, the P reference block, thus activating G71 Type I, then specified a shape with non-monotonous direction X moves. The fix is to specify both X(U) and Z(W) in the P referenced block as follows:

N315 G1 X13.9078 Z-0.806 F0.
or
N315 G1 X13.9078 W0.0 F0.

The F0. in the part shape description is ignored during the G71 operation, the F specified in the G71 block will be used. However, if the same blocks are used in conjunction with G70, then F0. will be a problem.

Regards,

Bill

[txcncman]

Not correct.

There are two versions of G71, Type I and Type II. Although Type II is an option, most machines are supplied with both versions. Type II was first introduced in the 6TB control.

G71 Type I only tolerates Monotonous direction X moves, whilst Type II profile need not show monotone increase or monotone decrease along the X axis, and can have up to 10 concave (pockets) forms.

To activate G71 Type I, only an X(U) move is specified in the first part shape description block referenced by P in the G71 block. Type II is activated by specifying both X(U) and Z(W) in the first block.

leszek0213's problem is that only X was specified in block N315, the P reference block, thus activating G71 Type I, then specified a shape with non-monotonous direction X moves. The fix is to specify both X(U) and Z(W) in the P referenced block as follows:

N315 G1 X13.9078 Z-0.806 F0.
or
N315 G1 X13.9078 W0.0 F0.

The F0. in the part shape description is ignored during the G71 operation, the F specified in the G71 block will be used. However, if the same blocks are used in conjunction with G70, then F0. will be a problem.

Regards,

Bill

I doubt he understood most of that.

[angelw]

I doubt he understood most of that.

And why would that be? Is it the same reason you're unaware that concave form (pocketing) is possible with the G71 Multi Repetitive cycle? Perhaps you can elaborate?

I tend to give people recognition of intelligence, and whether the OP is able to comprehend the post or not, its factually correct and of more benefit to the OP and other readers of the forum than incorrect information. This feature has been available on Fanuc controls for over 30 years, its nothing new; I'm surprised with the reading you've done that you haven't heard of it.

Hands up all those who didn't understand Post #3


In lay terms its as follows:
1. If the control is equipped with G71 Type II then change in direction of X is allowed if G71 Type II is active.
2. If the control has Type II it also has Type I
3. To activate Type I, command only an X or U(the incremental equivalent to the Absolute X) on the line referred to by P in the G71 block, block N315 in the OP's example.
4. If G71 Type I is active, change in direction of X is not allowed.
5. If the OP's control is equipped with G71 Type II, the example program has only activated Type I, but the part shape contains change in direction of X, which is not allowed if Type I is active. Hence the probable reason for the alarm (the actual alarm number and description was not posted by the OP).
6. To activate Type II, command both an X or U, and Z or W(the incremental equivalent to the Absolute Z) on the line referred to by P in the G71 block, block N315 in the OP's example.
7. If G71 Type II is active, change in direction of X is allowed to produces a profile with up to and including 10 concave (pockets) shapes.

If the leszek0213 needs clarification of any point, I, and I'm sure many other contributors to the forum, will be able to help.



Regards,

Bill

[txcncman]

You are correct as usual. I am outta here. Too many people here either know absolutely nothing or know way too much for anyone's good. No one seems to be middle of the road, K.I.S.S., get the job done but learn a little along the way. Well, that is how I roll. And this place ain't it.

[stevo1]

I tend to give people recognition of intelligence, and whether the OP is able to comprehend the post or not, its factually correct and of more benefit to the OP and other readers of the forum than incorrect information. This feature has been available on Fanuc controls for over 30 years, its nothing new; I'm surprised with the reading you've done that you haven't heard of it.

Hands up all those who didn't understand Post #3

Returning the comment...."Well said Bill".

You are correct as usual. I am outta here. Too many people here either know absolutely nothing or know way too much for anyone's good. No one seems to be middle of the road, K.I.S.S., get the job done but learn a little along the way. Well, that is how I roll. And this place ain't it.

This forum serves many purposes across many spectrums. Why does everyone have to be “middle of the road”?? I am curious as to why you would presume to think the people that ask simple questions “know absolutely nothing”. I have seen the most basic questions asked by the most experienced people. These questions are just typically things that they have not come across. Even the people that “know way too much for anyone’s good” learn something almost every day here.

I do have to honestly say that I do not want to see anyone leave…..including you. You seem knowledgeable in what you do and could contribute. The people that know nothing to the ones middle of the road on up to the people that know too much can always contribute their knowledge (this is how people learn). I am not trying to get all philosophical with this but I live very strongly by the “pay it forward” mentality and that there is no stupid question. I have seen your websites and you do training/consulting which is why it is so hard for me to grasp your presumptions about people here that are asking questions when that is supposed to be “your job”……to listen and advise.

If that is truly the way you feel then lets make it our goal to get the ones that know nothing up to the middle of the road.

Best of luck,
Steve

[stevo1]

Sorry leszek0213,
I don’t typically like to come to a thread and not contribute to the OP’s questions. So for the fear of embarrassing myself I will not elaborate on what Bill has already posted but will instead confirm what he stated is correct.

Stevo

[sinha_nsit]

Z finishing allowance would actually overcut the right side of the groove:
"N310G71P315Q345U0.01W0.005F0.012"