G76 thread

[cam-eleon]

Does anyone know the formula that Fanuc G76 uses to de-increment the depth of cut in the thread cycle. I know that I saw it in a 6T manual many years ago. I thinks it goes something like this:

1st pass depth = D ( the first depth in G76)

2nd pass D= D-sqrt of the pass number-1

3rd pass D= D-sqrt of the pass number-1

etc

[Andy]

What I looked up says;

N is the pass #

D= first path depth N=1

Second pass TOTAL depth D2=D*SQR(2)

Third D3=D*SQR(3)

Nth Dn=D*SQR(nth)

This is known as constant volume cut. ie

the same volume of material is removed every pass.

In my Mori there is a P parameter in the G76 code that allows for 4 different types of material removal

P1 as above

P2 constant material, alternating edge.

P3 constant infeed, single edge cutting.

P4 constant infeed, alternating edge.

Hope this helps.

Andy

------------------

Gordon Engineering

Eureka, Ca.

V8 Lathe and Mill

[Simtech]

Looked up in my Fanuc OT manual and it's the same as Andy wrote.

Luc

[cam-eleon]

Thanks all for the info!