Newbie SINGLE POINT NPT THREADING ON HAAS LATHE

1. ## SINGLE POINT NPT THREADING ON HAAS LATHE

I've been working on mills for years and this new job I'm working on lathes as well. I need help with threading a pipe thread. Please don't make fun .
G76 is pretty straight forward but if any of you guys knows what is the X value for this specific thread. And also why the said value, where did you picked it up.
If anyone knows how would this G76 line of command look like?
When turning for this specific size what is the correct diameter before threading.
Any nice help and explanations are greatly appreciated

2. ## Re: SINGLE POINT NPT THREADING ON HAAS LATHE

Hi,

As a European I can give you a Metric example for a Haas ST25Y Next Gen control for a Metric Fine thread M18 x 1.5
It's a M18 x 1.5 mm pitch with the numbers you can find in a thread table or the Internet.
Thread height is 0.92mm, so the minor diameter in X = 18 - (2x0.92) = 16.16 mm
Pitch diameter for your gauge is 17.026 mm
Haas uses Settings to control your parameters like Chamfer ON/OFF, Chamfer Angle, Minimum cut, Last cut, etc.
If you want a Chamfer at the end of the thread you have to program M23, if you don't want it M24.
Setting 95 is Chamfer Size ( multiplied by pitch, max. 1 ) and Setting 96 is Chamfer Angle, these numbers are for M23 - Chamfer ON.
Setting 99 is Minimum Cut in radius.
Setting 289 is Finish Allowance in radius / Last Cut.

Simple would be:
------
------
G00 X25. Z5.
M23 ( M23 = Chamfer ON or M24 = Chamfer OFF )
G76 X16.16 Z-20. K0.92 D0.25 A60 F1.5
------
------

X16.16 = minor diameter
K0.92 = height of thread for pitch 1.5mm
D0.25 = first cut
F1.5 = pitch 1.5mm

3. ## Re: SINGLE POINT NPT THREADING ON HAAS LATHE

For a tapered pipe thread, a G32 might work better. The thread calculations are all done in CAM rather than using the canned cycle on the Haas, but it does add many more lines of code to the program. I use G32 exclusively for all of my single point threading.

4. ## Re: SINGLE POINT NPT THREADING ON HAAS LATHE

First I want to thank you for your kind reply. However your reply still doesn't solve my dilemma. I was inquiring about pipe threading. The pipe thread has two diameters and I don't know how to pick my diameter, my X value that I need to put in the G76 line of code. If you know please tell me. Your help if appreciated

5. ## Re: SINGLE POINT NPT THREADING ON HAAS LATHE

Can you please let me know how would a G32 line of code look like for a 2.5 inch pipe thread?

6. ## Re: SINGLE POINT NPT THREADING ON HAAS LATHE

According the Haas manual they use a I - value in the G76 line similar like Fanuc uses a R for tapered thread.
It's a radial (X) value from start diameter to finish diameter (taper), it's no angle value, there's no example in the book for it.
This is what the manual says: I - Thread taper amount, radius measure
If you have the Next Gen control you can make an example for G32 or G76 with VPS, it will create the right code, I don't know for the older control.

7. ## Re: SINGLE POINT NPT THREADING ON HAAS LATHE

I have the manual, read it , understand it. I mean understand every address in the G76 line of command except one in this case.
G76 X??? Z-1.I-0.086 K0.05 D0.01 F0.088
This example is just an example, the numbers are not exact for a specific size of external pipe thread.
The following addresses is what I understand
Z is final distance in Z axis
I is the radial difference between the end point and start point of the thread. Negative value for external pipe thread
K is the radial final depth of cut . Depth of thread
D is the depth of cut for the first pass
F is the pitch of the thread.

What I don't know is the value of X. In this specific case I have to do a 2-1/2 NPT external thread. What is the X value for this thread and where do I pick the value from?

8. ## Re: SINGLE POINT NPT THREADING ON HAAS LATHE

Greetings,

I Googled Carmex Inserts as I use them in the shop.

Within the WebPage is an online thread calculator

.Carmex Tool Wizard - Welcome

It allows several Controllers for the Post Processing.

Hopefully, you have gauges to check the final size?

Cheers,

Dave

9. Originally Posted by Nick Doe
I've been working on mills for years and this new job I'm working on lathes as well. I need help with threading a pipe thread. Please don't make fun .
G76 is pretty straight forward but if any of you guys knows what is the X value for this specific thread. And also why the said value, where did you picked it up.
If anyone knows how would this G76 line of command look like?
When turning for this specific size what is the correct diameter before threading.
Any nice help and explanations are greatly appreciated

G0 X62.345 Z6.45
G75 X73.025 Z-35.243 I1300 K2540 D572 A60
F3.275

(ISO MM)

10. ## Re: SINGLE POINT NPT THREADING ON HAAS LATHE

Originally Posted by waer
G0 X62.345 Z6.45
G75 X73.025 Z-35.243 I1300 K2540 D572 A60
F3.275

(ISO MM)
Servus Waer. Aseara m-am gandit ce faceam gresit. De obicei cand esti aproape de actiune scapi ceva din vedere si asa s-a intamplat si de data asta. Am lucrat pe CNC Mills multi ani si acuma am un nou job unde lucrez freza si strung CNC. Informatia ce am dat-o aici este incompleta. Trebuie sa fac niste " dopuri " care sa inchida gaura ca sa putem sa testam niste piese sub presiune. Dopurile inchid cu garnituri de guma care au locul lor frezat in dop. Informatia incorecta este ca eu de fapt trebuie sa fac un filet incomplet de vreme ce filetul de teava nu se infileteaza pana la capat. Diametrul mare in cazul meu nu poate sa fie diametrul mare normal ci diametrul pana unde cele doua parti se infileteaza. Multumesc pentru ajutor oricum

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