[TGSTP]

I'm having trouble figuring out the G76 treading on my Alpha 400s Fanuc controll lathe. Even better they're NPT threads. Please Help!!

1"-11 1/2 npt
3/4-14 npt
1/2-14 npt

[Sump Cleaner]

TGSTP,

Here is a blurb on G76 threading. If you are doing an NPT thread you will have to use the R(i) value to taper the thread. The value is an interger number with 1 being equal to .0001" and is the difference in radius from Z start to Z finish. Hope this helps you out.

JK

G76 P(m)(r)(a) Q(min) R(fin)
G76 X(Øfin) Z(len) R(i) P(k) Q(1st) F(L)

WHERE
m = SPRING CUTS (01)
r = CHAMFER AMOUNT(00)
a = TOOL ANGLE (80 60 55 30 29 0)
min = MINIMUM DEPTH OF CUT
fin = FINISHING ALLOWANCE
Øfin = ROOT DIAMETER
len = LENGTH OF THREAD
i = THREAD RADIUS DIFFERENCE
k = THREAD HEIGHT (RADIUS)
1st = 1ST CUT DEPTH
L = THREAD LEAD

[gridley51]

As a help to finding the values to enter,Stelram has a small download programme on their site that works very well.
Mark.

[g-codeguy]

I'm having trouble figuring out the G76 treading on my Alpha 400s Fanuc controll lathe. Even better they're NPT threads. Please Help!!

1"-11 1/2 npt
3/4-14 npt
1/2-14 npt

Did you get this figured out yet? If not, then are the threads internal, external, or both? What kind of material? Does your control use a 2-block call as previously shown, or a 1-block call? I will help you if you haven't already figured it out. I would need to know at least one more thing, but no need to ask the question if you are already up and running.

[K&K]

can anyone help me i can't find anything on API threading. How do you figure out the angles and what not. Any help would be great.

Thanks K&K

[sinha_nsit]

If you are doing an NPT thread you will have to use the R(i) value to taper the thread. The value is an interger number with 1 being equal to .0001" and is the difference in radius from Z start to Z finish.

Are you sure?
The manual does not explicitly say that R is an integer value. Moreover, we use decimal numbers for R of G90. R of both the cycles have the same meaning. I have not used R with G76, so I am not sure. Please confirm.