Re-acquiring a thread ?

Re-acquiring a thread ?

Joined: August 20th, 2010, 5:56 pm

March 28th, 2012, 12:07 am #1

What is the best way to reacquire a thread after you remove a piece from your lathe & find out you need to make a few more cuts ? Not sure how to get threading dial back in syinc.

thanks
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Joined: June 16th, 2009, 7:43 pm

March 28th, 2012, 1:25 am #2

Then make the small adjustments with the Y axis and compound. Dykem your threads.

"Silence is the only thing that can hinder the Truth"
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Joined: August 20th, 2010, 5:56 pm

March 28th, 2012, 3:37 am #3

Just chuck-up the piece, set tool in the thread & reset dial to the proper line.(I HOPE)

I'm making a regulator for my disco. The wall thickness is .060 using a 28 TPI in aluminum. I thought the thread was cut to the proper depth so I removed the piece. Wrong ! The Aluminum was so shinny, I couldn't see it wasn't cut deep enough. At this point, I don't want to mess it up & have to start over.
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Joined: August 20th, 2006, 5:36 am

March 28th, 2012, 3:56 am #4

But isn't 28 TPI awfully fine for aluminum? Especially if it's going to be under pressure. Come to think of it, isn't .060" wall thickness kind of thin for 2K psi in aluminum, too? I'm asking, not telling, and the questions are based on the little I've learned about machining so far. Later.

Dave
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Joined: August 20th, 2010, 5:56 pm

March 28th, 2012, 4:48 am #5

The center section of the reg. contains the bellville spring washers and Ninja plunger assembly and has NO air pressure in it. (vented to exterior) Only 2K psi "crush" pressure pushing against o-ringed end of reg. Due to the dia. of the springs & plunger and the i.d. of the Disco tube, only .120 remaining = .060 wall.
The threaded section is not under any air pressure & just holds the two sections together. Thanks.
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Joined: August 22nd, 2001, 3:27 pm

March 28th, 2012, 11:17 am #6

What is the best way to reacquire a thread after you remove a piece from your lathe & find out you need to make a few more cuts ? Not sure how to get threading dial back in syinc.

thanks
of the thread first,this will be your gauge for the female half of the thread, which you check for depth by using the completed male half to test the fit. If you have to re-acquire the thread, set the part in the lathe, back the tool away from the part, set the head controls so that you can rotate the lathe head by hand, engage the thread feed and rotate the head by hand until the cutting tool is moving along the thread path, now bring the tool close to the thread and check the aliment between the thread and tool, a magnifier is helpful. Now check the ailment with the lathe running and the thread feed engauged. You always want to check the aliment under power with everything engaged. hth
Last edited by jpsaxnc on March 28th, 2012, 11:20 am, edited 1 time in total.
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Joined: July 24th, 2010, 1:44 am

March 28th, 2012, 1:17 pm #7

What is the best way to reacquire a thread after you remove a piece from your lathe & find out you need to make a few more cuts ? Not sure how to get threading dial back in syinc.

thanks
http://www.youtube.com/watch?v=FfwdsBYJN34
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Joined: August 20th, 2010, 5:56 pm

March 28th, 2012, 1:30 pm #8

of the thread first,this will be your gauge for the female half of the thread, which you check for depth by using the completed male half to test the fit. If you have to re-acquire the thread, set the part in the lathe, back the tool away from the part, set the head controls so that you can rotate the lathe head by hand, engage the thread feed and rotate the head by hand until the cutting tool is moving along the thread path, now bring the tool close to the thread and check the aliment between the thread and tool, a magnifier is helpful. Now check the ailment with the lathe running and the thread feed engauged. You always want to check the aliment under power with everything engaged. hth
Since the wall thickness of the female half is only .060, I thought I should cut it first to avoid cutting to deep. With a 28 TPI, the single thread depth is .027 almost half the thickness. I would then cut the male half to fit, as it is about 1/4" thick at that area. (more metal to play with safely) Oh well, live & learn I guess. Either way, I'll get it.

thanks
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Joined: August 20th, 2010, 5:56 pm

March 28th, 2012, 1:50 pm #9

Thanks Ed ! Good find on your part ! Very informative, I'll save that one for sure. There is more to it than I thought.

By the way, is that your video ? Nicely done!

thanks again
Last edited by Harleyrider05 on March 28th, 2012, 1:56 pm, edited 1 time in total.
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Joined: July 24th, 2010, 1:44 am

March 28th, 2012, 2:01 pm #10

YouTube for videos on how to single point thread with a lathe and stumbled upon this last night.
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