OD Threading Lathe

This is the subroutine I use for OD Threading on the lathe.

image missing http://www.linuxcnc.org/media/kunena/attachments/legacy/images/Thread_OD.png



John

Likely me being confused, but is parameter 3 the start / total diameter of the piece or the radius?
Or put another way, would the example in the screen shot make a 3/4 - 16 od thread or a 3/8 - 16 od thread.
Looking at the G76 code it seems to be the radius, or the difference between the drive line and the thread peak, where the thread peak is expressed as a radius.( I think )

I have yet to thread anything successfully, found this and thought it would be a great tool to get me started, and want to make sure I understand.

BTW, I thought putting the G76 image in with this might be helpful, but the more I look the less sure I am, it seems like you would need an explanation as to how the parameters get mapped, and it might get too busy. Something like this but cleaned up.

image missing http://www.linuxcnc.org/media/kunena/attachments/legacy/images/th_od_in_ngcgui.png

At any rate, John, thanks a ton for putting these up, and Dewey, you are some kind of crazy geek / artist hybrid thanks for the code, and I love your woodworking.

Pete

otto_pjm wrote:

Likely me being confused, but is parameter 3 the start / total diameter of the piece or the radius?
Or put another way, would the example in the screen shot make a 3/4 - 16 od thread or a 3/8 - 16 od thread.
Looking at the G76 code it seems to be the radius, or the difference between the drive line and the thread peak, where the thread peak is expressed as a radius.( I think )

That example is for a 3/8-16 thread. The diameter + the X offset describe the start X position.

I have yet to thread anything successfully, found this and thought it would be a great tool to get me started, and want to make sure I understand.

BTW, I thought putting the G76 image in with this might be helpful, but the more I look the less sure I am, it seems like you would need an explanation as to how the parameters get mapped, and it might get too busy. Something like this but cleaned up.

image missing http://www.linuxcnc.org/media/kunena/attachments/legacy/images/th_od_in_ngcgui.png

At any rate, John, thanks a ton for putting these up, and Dewey, you are some kind of crazy geek / artist hybrid thanks for the code, and I love your woodworking.

Pete

I like the image idea and if you can post that with parameter 3 showing diameter somehow that would be great.

John

re-worked the image a bit, and I'm hopefully understanding better, put it with the th_od.ngc file and it should appear in the tab when opened.

image missing http://www.linuxcnc.org/media/kunena/attachments/legacy/images/th_od.png

Pete

LOL, now I have to figure out how to attach the image...

Thanks
John

It's automagic, once the tab exists, you just put the image (same name with .png) in the same directory. There's one option as to it's location, but I don't think I needed to mess with it.

Pete