Starting a thread on the lathe with a die

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earlgo
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Re: Starting a thread on the lathe with a die

Post by earlgo » Mon Jan 01, 2018 11:18 am

+1 on the spigot. It has worked for me for many threads.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.

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tornitore45
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Re: Starting a thread on the lathe with a die

Post by tornitore45 » Mon Jan 01, 2018 11:32 am

RSG threading on the lathe is like riding the bicycle. Pros do it fast but you can use as slow an RPM as you can. If you have a landing groove at the shoulder is really easy, just try or practice with a fake shoulder on PVC.
I can stop my spindle "on a dime" by slackening the belt, other lathes may need different approach.
Mauro Gaetano
in Austin TX

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BigDumbDinosaur
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Re: Starting a thread on the lathe with a die

Post by BigDumbDinosaur » Mon Jan 01, 2018 1:29 pm

tornitore45 wrote:RSG threading on the lathe is like riding the bicycle. Pros do it fast but you can use as slow an RPM as you can. If you have a landing groove at the shoulder is really easy, just try or practice with a fake shoulder on PVC.
I can stop my spindle "on a dime" by slackening the belt, other lathes may need different approach.
All of the lathes I have used couldn't instantly stop. If tapping or if threading with a die, I usually take it slow so I don't have an "accident." I always suggest to a beginner to take it slow.
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Re: Starting a thread on the lathe with a die

Post by RSG » Mon Jan 01, 2018 5:27 pm

John Hasler wrote:I like the idea of a spigot turned to the minor diameter rather than just a chamfer. If it's about as long as the die the die will be perfectly aligned when it starts cutting the first thread.
This is a great idea!
Vision is not seeing things as they are, but as they will be.

RSG
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Re: Starting a thread on the lathe with a die

Post by RSG » Mon Jan 01, 2018 5:32 pm

Mauro, I have done some single point threading on larger items and while not proficient nor elegant I can get the job done but this stuff is so small I would need way more practice than I have time for. The die I'm using does a very nice job once started it was just the face of the thread that was bad and it needs to be flat to accommodate the mating part. Now, with the idea of going back and trimming it to final length the problem is solved.
Vision is not seeing things as they are, but as they will be.

RMinMN
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Re: Starting a thread on the lathe with a die

Post by RMinMN » Tue Jan 02, 2018 9:08 am

RSG wrote:Glenn, I thought about doing it on the lathe but I'm not well versed on threading up to a shoulder that small and I have about 14 to do as well. I wish I could do it, it's one skill I've avoided perfecting.

I do like John and Mauros ideas and will give them a try today.

Thanks for the input guys and Happy New Year to the board!
Turn your threading tool upside down, set the lathe in reverse, and thread away from the shoulder. If you cannot have a runout groove you will need to turn the lathe by hand which is easiest done if you have made a crank that locks into the spindle. Even if you do not make the thread full depth it will help guide the die and keep it threading true and it takes a lot less force to cut a shallow amount of thread with the die than full depth.

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GlennW
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Re: Starting a thread on the lathe with a die

Post by GlennW » Tue Jan 02, 2018 10:25 am

RSG wrote:Glenn, I thought about doing it on the lathe but I'm not well versed on threading up to a shoulder that small and I have about 14 to do as well. I wish I could do it, it's one skill I've avoided perfecting.
You need a Cazenouve lathe like Patio's. :D

That's a piece of hardware there!
Glenn

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

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BadDog
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Re: Starting a thread on the lathe with a die

Post by BadDog » Tue Jan 02, 2018 11:48 am

GlennW wrote:You need a Cazenouve lathe like Patio's. :D
Don't we all!
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AllenH59
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Re: Starting a thread on the lathe with a die

Post by AllenH59 » Wed Jan 03, 2018 11:59 pm

I learned how to single point threads, you can too.

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Re: Starting a thread on the lathe with a die

Post by spro » Thu Jan 04, 2018 1:31 am

Welcome to the board RMinMN.

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Re: Starting a thread on the lathe with a die

Post by RMinMN » Thu Jan 04, 2018 6:43 am

Thank you for the welcome. I had been following this board as I wanted to learn more about using the machines I bought and to refresh memory or how machining should be done from the small amount of classwork I did some 40+ years ago. I supplemented this board with a couple others and watched a lot of Youtube machinists, some of which are quite good. Eventually I realized that some of what I had learned could be passed on to others who might have similar problems so I joined so I could have some input and feedback.

spro
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Re: Starting a thread on the lathe with a die

Post by spro » Thu Jan 04, 2018 7:17 am

Much of what we describe has been said before but there are new "twists". It is good to have new people aboard. Many of the same machines have served beyond expected life and have issues unforeseen. These things are or have been addressed. The "search" engine is wonderful and you'll note the absence of "pop up" advertisements and distractions.

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