G76 - cutting threads in one pass.

[AAA]

Got some internal threads that I'm wanting to chase after being re-bored.

Threads cycle is thus:

G76P020055Q10R0.001
G76X0.375Z-0.490P135Q40F0.0250R0

To cut them in one pass for chasing, I'm using:

G76P000055Q10R0
G76X0.375Z-0.490P135Q135F0.0250R0

It's cutting two passes as full depth, rather than one. Where am I screwing up here?

Thanks.

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[dcoupar]

G'day, Mate.

Please check the value of parameter 5142... should be 0.

What happens if you change Q135 to Q140? (Try it away from the part please).

I know that I've done this successfully on older controls, but I may not have done it on the 0iTD.

Dave

[dcoupar]

Well, I'm a little confused at this point. According to the 0iT-D Lathe Operator's manual, the value of the first two digits in the P000055 range from 1 to 99. It also says that the value is stored in prm 5142.
Let's try P010055, and in both blocks make the Q135... again, away from the part.

[AAA]

OK, so as per above:

G76P010055Q135R0
G76X0.375Z-0.490P135Q135F0.0250R0

Cuts two passes at 0.375"

When I change Q135 to Q140 it cuts 3 passes. One at 0.374" and two at 0.375".

When I go into the settings, my parameters jump from 5011 to 5213. So I'm obviously not looking in the right area?
I'm using the settings area - where one also has G54 and parts count setting?

cheers

[AAA]

Using the System button on keypad (I can't believe I missed that!), went into setting 5142 (G76 FINISHING REPETITION), this is currently set to "1".

I went into Handy page, and changed settings to write enable (while in MDI) and tried to changing the parameter to zero to see what that would do. It allows the input of "0", but it still cuts 2 passes. When I go back into the parameter, it's changed itself back to 1!

[sinha_nsit]

... the value of the first two digits in the P000055 range from 1 to 99...

That is correct, and because of this reason, I think two passes would always be there.

[dcoupar]

Mike,

Maybe I'm imagining things, but I could swear I've done this successfully... maybe not.

Is this issue keeping you from making parts?

You might want to post this on the Daewoo/Doosan forum. They have a couple of really smart guys monitoring and answering questions.