NTP
06 Sep 2011 15:01 - 06 Sep 2011 17:30 #13006
by BigJohnT
Last edit: 06 Sep 2011 17:30 by BigJohnT.
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01 Dec 2012 02:16 #27105
by jlviloria
John
I can help make internal NPT threaded. I am analyzing the file that you enclose the truth but still do not quite understand the subroutines.
I see you say not to use. because there is a mistake, I need do npt threaded:
1 "1/4 npt
1 "1/2 npt
2 "npt
can guide me how I can make these threads?
Jorge
Colombia
I can help make internal NPT threaded. I am analyzing the file that you enclose the truth but still do not quite understand the subroutines.
I see you say not to use. because there is a mistake, I need do npt threaded:
1 "1/4 npt
1 "1/2 npt
2 "npt
can guide me how I can make these threads?
Jorge
Colombia
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14 Dec 2012 11:47 #27718
by joekline9
Here are some G code files to cut NPT tapered pipe threads.
They now do the spring passes and auto calc the compound feed angle from parameters #50 & #51.
You can change parameters #39 thru #58 to cut any thread, straight or tapered.
If #39 (X Start Point) and #52 (X End of thread) are the same it will cut straight.
Normaly #51 (Z cut Depth) is 1/2 of pitch (#41). That gives you 30 degree compound angle of in feed.
#51=0.0 it will plunge in ( 0 degrees).
I will post more sizes when they are done.
John,
I should have used named params but this is my 1st attempt at params in LinuxCnc
and I wasn't to sure how to use them.
Thanks for the tip.
PS:
Maybee in a future release of LinuxCnc G76 could have an X word to allow it to do tapered threads.
What do you think.
They now do the spring passes and auto calc the compound feed angle from parameters #50 & #51.
You can change parameters #39 thru #58 to cut any thread, straight or tapered.
If #39 (X Start Point) and #52 (X End of thread) are the same it will cut straight.
Normaly #51 (Z cut Depth) is 1/2 of pitch (#41). That gives you 30 degree compound angle of in feed.
#51=0.0 it will plunge in ( 0 degrees).
I will post more sizes when they are done.
John,
I should have used named params but this is my 1st attempt at params in LinuxCnc
and I wasn't to sure how to use them.
Thanks for the tip.
PS:
Maybee in a future release of LinuxCnc G76 could have an X word to allow it to do tapered threads.
What do you think.
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14 Dec 2012 19:37 - 14 Dec 2012 19:51 #27722
by BigJohnT
I think there has be quite a bit of discussion on taper threads and no one seems motivated to actually take on the task.
Named parameters are your friend and make code so much more readable.
I converted one of your files to use named parameters...
John
Named parameters are your friend and make code so much more readable.
I converted one of your files to use named parameters...
John
Last edit: 14 Dec 2012 19:51 by BigJohnT.
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15 Dec 2012 00:12 #27733
by andypugh
There is a "gotcha" with tapered threads and G33. G33 moves at the desired pitch along the path, not along the Z axis.
This may not be noticable for a shallow angle, but does need correcting for.
(This may look like a drawback, and some people consider it a bug, I am of the opinion that it allows for more flexibility, creating scroll chucks for example.)
Here are some G code files to cut NPT tapered pipe threads
There is a "gotcha" with tapered threads and G33. G33 moves at the desired pitch along the path, not along the Z axis.
This may not be noticable for a shallow angle, but does need correcting for.
(This may look like a drawback, and some people consider it a bug, I am of the opinion that it allows for more flexibility, creating scroll chucks for example.)
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