Thread Milling

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Les_S
Posts: 97
Joined: Thu Jul 21, 2011 11:09 am
Location: Cheyenne, WY

Re: Thread Milling

Post by Les_S » Tue Mar 26, 2019 1:15 pm

Interesting subject! Just curious, I'm assuming that the process for pipe threads would be a little different than the process used for a straight thread. How do you account for the taper? My old Heidenhain controller will do helical interpolation so I'm anxious to get a cutter and try it out!
Thanks,
Les

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GlennW
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Re: Thread Milling

Post by GlennW » Tue Mar 26, 2019 5:00 pm

In my case, the cutter that I am using has the correct taper for NPT ground on it.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

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NP317
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Re: Thread Milling

Post by NP317 » Tue Mar 26, 2019 7:36 pm

A CNC lathe I've have used can be programmed to cut threads in a taper, using internal subroutines.
Programming was "conversational" so taper threads were easy, simply answering questions from the software.
I sure wish I had one of those lathes at home!
~RN

Les_S
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Location: Cheyenne, WY

Re: Thread Milling

Post by Les_S » Tue Mar 26, 2019 8:43 pm

Thanks guys.
So Glen, I'm guessing that you cut the OD to size and then mill from the top to the bottom and the multitooth tool has the correct taper so the taper widens as it progresses down the shaft? Sorry for the silly questions but what you have shown is really cool! I'm guessing you couldn't do tapered threads with a single profile tool without some serious programming correct?

RN - I suspect that your cutter is just the usual 60 degree threading tool and your tool backs away from the center line as you approach the chuck? Or is the tool in the spindle and your cross slide moves to make the cut? cool stuff!

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NP317
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Re: Thread Milling

Post by NP317 » Tue Mar 26, 2019 11:49 pm

Les_S wrote:
Tue Mar 26, 2019 8:43 pm
[snip]
RN - I suspect that your cutter is just the usual 60 degree threading tool and your tool backs away from the center line as you approach the chuck? Or is the tool in the spindle and your cross slide moves to make the cut? cool stuff!
Yes, the single point tool is on the carriage, which is moved in the X-Z directions to cut the treads while backing away to follow the pre-turned taper.
~RN

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GlennW
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Re: Thread Milling

Post by GlennW » Wed Mar 27, 2019 9:31 am

Les_S wrote:
Tue Mar 26, 2019 8:43 pm
So Glen, I'm guessing that you cut the OD to size and then mill from the top to the bottom and the multitooth tool has the correct taper so the taper widens as it progresses down the shaft?
That is correct.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

Les_S
Posts: 97
Joined: Thu Jul 21, 2011 11:09 am
Location: Cheyenne, WY

Re: Thread Milling

Post by Les_S » Wed Mar 27, 2019 10:16 am

Thanks guys - I appreciate the info
Les

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