# 3 Start Threading on your new metal lathe



## skiprat (Nov 1, 2009)

Here is a method of making 3 start threaded parts for your capped pens.
Before I get shot down in flames, I appreciate that purists will say the topslide SHOULD be set at 29deg etc etc, but I believe that with shallow fine cuts that doing it this way is just fine. 
I will need to add some text that I couldn't fit on some of the pics.
This is just repetitive text so I'll only write it once even though you will have to repeat it several times. :biggrin:

The pics are numbered in the sequence that they are done, T1, T2 etc


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## skiprat (Nov 1, 2009)

more..


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## skiprat (Nov 1, 2009)

May needs some text here..

When you have done the first 'scratch' cut, back off the cross slide, then reverse the carriage till the cutter is back above the relief area near the tailstock. Now set the Topslide to zero.Now put the Cross slide back to the zero that you have already set. 
I did each thread with two passes, first at 0.5mm then at 1.0mm. Remember to back off the Cross slide before reversing the machine back to the beginning.
Also remember to switch the machine from reverse to forward !!!Or you will crash and burn!!


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## skiprat (Nov 1, 2009)

When the first thread is complete, and you have reversed the machine back to the beginning, simply advance the Topslide by 1mm. Now just repeat like you did for the first thread.
Same again when the second one is finished.
Things to remember are; 
Don't forget to back off the cross slide before reversing.
Don't forget to switch back to forward before cutting
Don't lose your zero points
and NEVER dissengage the Half -Nuts till the job is complete.

These instructions are for a manual change gearbox and a metric lathe doing metric cuts but the principle should work on any lathe

My next little pictorial will show how to use this threaded rod to make pen parts and to make a tap for the cap threads.


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## devowoodworking (Nov 1, 2009)

Wow, thanks for sharing...I think I'll stick to puzzlemaking :biggrin:


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## Jim15 (Nov 1, 2009)

Thank you for the tutorial, way above my capabilities but it gives me a little knowledge of something I had no idea about.


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## furini (Nov 1, 2009)

Skip, these tutorials are great - really looking forward to the next one!

Thanks

Stewart


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## kevin miller (Nov 1, 2009)

keep this up i will needto get a new machine. thanks kevin


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## jleiwig (Nov 1, 2009)

I can't wait to get my metal lathe!  Someone buy my Jet so I can make triple start threads like Skippy! Great tutorial!


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## Dan_F (Nov 1, 2009)

Thanks for taking the time to do this, can't wait to see the next installment. This is rekindling my desire to get a metal lathe. 

Dan


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## Chuck Key (Nov 1, 2009)

Skip, you make it look easy but I wish you had put it in English or at least TPI. I use a mini lathe that many people here have and set it to 6 TPI then cut 4 starts into that or the equivalent of 24 TPI. Were you advance the top slide 1mm I advance mine 1/24 inch which is .041666 or .042 inches. That is one full turn plus 2 tick marks on the top slide . Where you advance two times I advance the top slide three times to get to 4 starts. Where your thread depth is 1mm mine is .032 inches. I will not go into the calculations to get the depth of cut. Fortunately all these numbers are available in charts. The next time I do this I am going to see how your three start looks. That would be only two one full turns on my top slide for the threads and one full turn on the cross slide for the depth. 

Can not wait to see your tap.

I have been using the above procedure on the female threads as well :frown:

Chuckie


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## Russianwolf (Nov 1, 2009)

Skippy, you are making me drool waiting to get my Grizzly metal lathe. I'm about a month away from ordering one I think.


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## workinforwood (Nov 2, 2009)

Pretty sure my lathe is metric and I do prefer metric over standard.  The numbers are just so much simpler to understand.  There's no fractions to convert.  I can't study this right now because I"m running off to work, but now that you have a triple start threaded rod, how are you going to match that inside a cap???  That seems quite intimidating. I'd be pretty darn happy with a single start thread.  I have been looking around in a few magazines and have yet to find a boring bar and thread cutter that fit's inside a 3/8-1/2" size hole.  look forward to seeing what you do with this threaded rod you made!


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## jleiwig (Nov 2, 2009)

workinforwood said:


> Pretty sure my lathe is metric and I do prefer metric over standard. The numbers are just so much simpler to understand. There's no fractions to convert. I can't study this right now because I"m running off to work, but now that you have a triple start threaded rod, how are you going to match that inside a cap??? That seems quite intimidating. I'd be pretty darn happy with a single start thread. I have been looking around in a few magazines and have yet to find a boring bar and thread cutter that fit's inside a 3/8-1/2" size hole. look forward to seeing what you do with this threaded rod you made!


 
Could he make his rod into a tap?  If he wasn't tapping anythign overly hard he could just cut flutes into his rod to make a tap from it.


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## JeffinWIS (Nov 2, 2009)

Jeff, REALLY small tools available here..........scroll to the bottom of the page for internal threading, grooving,etc.

http://www.kaisertool.com/New_Prod/Product Overview Flyer 2007.pdf

Or you could make your own.  This one will go in a 5/16" bore...


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## workinforwood (Nov 5, 2009)

Steve..I see you have a tool in which to compare your thread cutter to.  A guage would be a better word.  Is there different size cutters for different threads, or does one cutter pretty much cover all threads?


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## Russianwolf (Nov 5, 2009)

Jeff, the size isn't as important as the angle. Notice on the gauge that the one side is 60", while there is 55" on the opposite. 

60" is the standard for us. But as long as both the internal and external threads match in terms angle, you're fine.


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## glycerine (Nov 9, 2009)

Can I do this with pretty much any decent metal lathe?  I'm looking into getting one, but it definitely needs to cut threads or there's no point in my opinion.  Or is it just as easy to get and use a tap and die?


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## Paul in OKC (Nov 9, 2009)

Nice stuff, there skippy. If you have an inch lathe it can still be done easily. And no, I don't put the compound at 29 degress. Just dial in and rip it!


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## Gin N' Tonic (Nov 9, 2009)

You know something?

I made a lathe dog that straddles the jaw of my chuck so all I have to do is cut one thread, switch to the next jaw and cut another, switch again and I'm done.

Psssst, works well on my 4-Jaw chuck to :wink:

Got another lathe dog that hooks into the faceplate If I want to get fancy with more starts. I have also been fiddling with interrupted start threads and found that they work quite well with a single thread. But I'm still trying to perfect it before I try iy on a pen that I sell.


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## NewLondon88 (Nov 9, 2009)

Ok, I'm trying to picture this..


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## Ligget (Nov 9, 2009)

Fantastic tutorial Steve!


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