Question About G71 Code in PathPilot Conversational

Lathe
1

Hi Everyone,

I am running the 8L lathe machine using PathPilot Conversational to fabricate a spinning part. The program includes the following G71 code:

G71 P1103 D0.02 F0.005 J0.006 L6 I0.003 K0.003 R0.02 E1;

Could anyone help me understand the meaning of J0.006, L6, I0.003, K0.003, and E1? This format does not seem to follow the standard G71 structure, and I find it quite confusing.

Any insights would be greatly appreciated!

Thanks,
Jie

2

I’m not in front of my 8l but dug into this kind of recently. The J I and K values relate to the F&S you set up in your program. I don’t recall which is which but when I was curious I made a dummy program and changed the settings around to figure out what is what.

3

So it’s not making the part correctly?

4

Works fine for me. I dig in a while back because I was curious.

5

Hi Davie,

Thanks!

I set the Finishing DOC to 0.003 and Finishing Passes to 2. I guess the J value represents the total allowance for finishing, while the I and K values indicate the Finishing DOC in the X and Z directions, respectively. What do you think?

Additionally, do you know what is the meanings of L 6 and E1? I suspect that L 6 refers to the number of roughing passes and E1 relates to tool nose compensation, but I couldn’t find any reference to these in the documentation provided by Tormach.

Looking forward to your insights!

Thanks,
Jie

6

Hi Dr. Harold,

The part is being made correctly, but I would like to understand each line of the G-code. Tormach does not follow the standard use of G71, and I have been unable to find any reference materials explaining its implementation.

Do you have any insights or resources that could help clarify this?

Thanks,
Jie

7

@Jie_Yao we haven’t looked at this routine in a while but were able to dig this up:
P word = 0 # Block Number of contour beginning (uses N word in beginning block)
D word = 0 # Roughing Depth per cut
R word = 0 # Retraction from each cut
J word = 0 # Overthickness before finishing X (diameter) (U on other controllers)
L word = 0 # Overthickness before finishing Z (W on other controllers)
I word = 0 # Thickness for finishing at X
K word = 0 # Thickness for finishing at Z
F word = 0 # Feedrate override between P and Q blocks
S word = 0 # Spindle speed override between P and Q blocks
T word = 0 # Tool for cycle

The E word is used deeper in the code and I will post here when I have a sec to dig into that one.

1 Like