G71 problem on OT control

First this control doesn't allow a Z(W) on the first block for Type 2 (I believe) cycle. Not a biggie. Can't use brackets inside the G71, so I thought I would get smart and set my program up a bit differently than usual. Start position may look a little off because it is using a lead angle turning tool.

The problem is...as written...it turns .4665 (.4765 actual, natch) diameter for the full length UNTIL the last pass. On the last pass it turns all the diameters as it should. Why? I'm converting to my usual way of running so the lathe won't be sitting idle, but I'd like to know if there is a way of programming as in this example. Thanks.

X1.Z.5
G50S3000
G96S650
Z-.05
G1Z-.08F.012
#1=.2995+#510
#2=.4655+#511
#3=.513+#512
#4=.513+#513
#5=.5565+#514
#6=.7635+#515
G71U.053R.01
G71P11Q12U.01W.005F.008
N11G1X#1
U.1181Z-.1391
U.0479Z-.1806 (X.4655)
X#2Z-.5495 (X.4655)
X#3W-.0238 (X.513)
X#4Z-.965 (X.513)
X#5W-.0233 (X.5565)
Z-1.4443
X#6W-.0277
U.0385W-.0333 (X.802)
Z-1.713
N12X1.W-.03

What do you gain by making a simple threading cycle so much more complicated.
Is it for job security?.
To tell the truth, I have been teaching this cycle for many, many years, including while teaching the Fanuc classes in Chicago and I have no idea what you are even asking/
What are you asking?
By the way, there are several examples of the G71 on my website. Fanuc CNC programming training. Learn CNC for Fanuc, Yasnac, Mitsubishi CNC controls, CNC Machining Videos and DVD's, CNC programming training, CNC education,and CNC consulting.
Good luck:
Heinz.

Heinz R. Putz said:

What do you gain by making a simple threading cycle so much more complicated.
Is it for job security?.
To tell the truth, I have been teaching this cycle for many, many years, including while teaching the Fanuc classes in Chicago and I have no idea what you are even asking/
What are you asking?
By the way, there are several examples of the G71 on my website. Fanuc CNC programming training. Learn CNC for Fanuc, Yasnac, Mitsubishi CNC controls, CNC Machining Videos and DVD's, CNC programming training, CNC education,and CNC consulting.
Good luck:
Heinz.

Click to expand...

Ah Heinz,
G71 is a Multi Repetative Roughing cycle in the Z axis.

Regards,

Bill

Angel:
Thanks for the correction.
How are things in your part of the world?
Do you do outside CNC training for shops?
I would be very interested what it is like to live where you are.
Please write back, I am sure I am not the only one interested.
Heinz.

Brackets can be used inside G71 for arithmetic calculations.
For example, X[#1 + #500] is allowed.

The program looks ok, at least with assumption of zero values in #500 series variables.