Cutting Threads without CNC

[Historian]

I ran across a 'long lost' demonstration by an old machinist,
the kind I looked up to in the 1950's before I start threading
a piece soon.

<< http://www.youtube.com/watch?v=qpRX-ffL274 >>

The great physicist Dick Feynman would often go back to a
problem his high school math teacher started him on (Calculus of Variations) and
each time gain further and deeper insights which in turn opened up his physics.

When the CNC dies.

[MCKNBRD]

Can't see the video here at work, but your post is VERY timely.

I'm looking at getting a machine that has CNC controls, but is coming with gears for threading; I thought the Z axis control would take care of the threading feed rate. I've got an email in asking about a little clarification, but was wondering what the ST braintrust thought about threading...

Better to use the half nut and manually thread, or program it and get out of the way?

Thoughts?
Byrdman

[CThomas]

Personaly I have always been a fan of "tubalcain" and the "Viper" over on the tube.

[punkinhead]

I've never understood all the apparent fear of single point threading on the lathe. Based on the different forum questions and youtube videos you'd think it was some arcane skill taking a 4 year apprenticeship to master when the truth is I could have anyone threading on a manual lathe in 10 minutes. It just isn't as hard as people seem to want to make it.

[HandyMan]

I've never understood all the apparent fear of single point threading on the lathe. Based on the different forum questions and youtube videos you'd think it was some arcane skill taking a 4 year apprenticeship to master when the truth is I could have anyone threading on a manual lathe in 10 minutes. It just isn't as hard as people seem to want to make it.

Truth. When I went to school, we had to build several complete projects with nothing but manual machines. Not even a DRO. The key is practice.

Start at the slowest spindle speed your lathe offers and thread some scrap aluminum. Do it over and over until it is easy. Then speed things up. Manual threading is quite straight forward. Internal threads may seem scary, but you set up an indicator to show you when to pull the half nuts.

Just don't get mesmerised watching the needle spin round and round. Happened to one kid in my class. The ugly noises woke him right up.

[IAC533]

Tubalcain is THE master. I have learned so much about running my lathe from his videos.

[ghostdog662]

That's how i still do it. Best way to crash a lathe ever lol.

[Historian]

An oft forgotten but key step is setting the compound rest at 29º ... nearly
half of 60º thread. Reason: you want to cut with one side of the tool.
There are some machinists who cut straight in and get a passable thread
but not for those with refined tastes ... and expensive weapons ... on this site.

An example, the threading of a PPKS barrel with HSS tool ... diamond honed
to a razor's edge under a magnifier.

When I have cut specialty threads on my small Atlas 618 lathe, I made
a spindle hand crank that sits on the back of the lathe spindle. It is amazing how
much control one has and the tactile feel of metal characteristics and
finish is so satisfying.
[ Johnny B., cranky old SOB machinist/manager's ghost would be grudgingly proud of me ...
"I may not do good work, but I am slow". ]

<< http://www.deansphotographica.com/machi ... crank.html >>

Also:
<< http://www.youtube.com/watch?v=XMUY6ip14sM >>
<< http://www.bedroom-workshop.com/tools-l ... crank.html >>
<< http://www.penturners.org/forum/attachm ... dcrank.jpg >>
<< http://andysmachines.weebly.com/miscellaneous.html >>

If you have a small MT2, or whatever spindle diameter/taper your lathe has, collet then you
fit the collet in the front behind the chuck and the crank grabs hold easily.

In reprise, the satisfaction and tactile response using a hand crank is on par with
working on souping up ( is this phrase dated?? ) you car as opposed
to buying a fast production car off a lot.

Please let us know of your experience.

[Fulmen]

but not for those with refined tastes

Bah! Full profile inserts and the highest speed you can pull off without crashing. Perfect threads every time

[Historian]

but not for those with refined tastes

Bah! Full profile inserts and the highest speed you can pull off without crashing. Perfect threads every time

Impressive.

A machinists who can do that, Sir, you are indeed a high-wire act artist in this circus of
swarf makers. I tip my hat to you and anyone with that skill,facility, and success.

In comparison then I must be honest and rate my machining skills at the level of the circus gentleman who in the
dark follows the elephant with a broom and pick up pan.

Best.

[57fairlane]

I always stopped the spindle, backed out in X, reversed the spindle to where I wanted and flipped direction back to forward.

Never even looked at the dial in school

[Fulmen]

I'm joking a bit of course, I'm no skilled machinist. But honestly, full profile inserts are the proper way to go if you can afford it. I'm lucky in that I can get a proper insert for most metric and some unified threads when I need without having to buy a set, this may not be common for most amateur machinists. But they really are great, as long as you have a sturdy setup you can feed straight in and get a clean thread with the proper dimensions by only measuring the OD. And they come out burr free every time.

As for speed, that's just a matter of practice. Always try to keep the speed up if you can.

[Historian]

I always stopped the spindle, backed out in X, reversed the spindle to where I wanted and flipped direction back to forward.

Never even looked at the dial in school

+1!

This has also been my simple minded way to avoid guessing when counter came around.
Hand cranking the lathe like a organ grinder is the luxury of having no one else structuring
your time.

Any excuse not to cogitate, solve, condense, collate, and finally write up.

[Baffled]

Nickole "mini-thin" threading inserts in their Swiss-style tools is the cat's ass for external fine threading jobs. Those inserts cut you just looking at them. You start to spontaneously bleed at the fingertips.

Just about every beginner starts with crappy brazed tools, the $6/dozen jobs, and wonder why their work looks like a chimp with a hack saw and cold chisels did the job. Good work comes not only from a good machine, but also quality tooling.

[Historian]

Nickole "mini-thin" threading inserts in their Swiss-style tools is the cat's ass for external fine threading jobs. Those inserts cut you just looking at them. You start to spontaneously bleed at the fingertips.

Just about every beginner starts with crappy brazed tools, the $6/dozen jobs, and wonder why their work looks like a chimp with a hack saw and cold chisels did the job. Good work comes not only from a good machine, but also quality tooling.

+1!

As you so humorously put it, otherwise you will be monkeying around like a democrat wrapping his tail
around a flag pole so he can see his ..... Ah... Ah... What was the end of this line?

Thank you for bringing up the "Nicole "mini-thin" shank with a threading insert"
This will be the next 'must' purchase for a fugitive from TJA ... Tool Junkies Anonymous.


Remembered this old informative reference:
<< http://www.homegunsmith.com/Archive/T12928.html >>

[Fulmen]

Those should be perfect for small scale machining since they can be used both for ID and OD, it's hard enough to keep a complete stock of such inserts as it is. Don't know how cost effective they are compared to the traditional triangular inserts though. As for quality tooling, I'd rather use cheap holders and expensive inserts if I have to choose.

[Historian]

Those should be perfect for small scale machining since they can be used both for ID and OD, it's hard enough to keep a complete stock of such inserts as it is. Don't know how cost effective they are compared to the traditional triangular inserts though. As for quality tooling, I'd rather use cheap holders and expensive inserts if I have to choose.

Please direct us to the inserts you would recommend. I have the cheap holders.
I would not use the inserts for threading as you point out they are cheap. Thus
for threading I have relied on HSS, tediously honed, and under glass diamoned
polished.

Thank you.

[Baffled]

Nickole "mini-thin" threading inserts in their Swiss-style tools is the cat's ass for external fine threading jobs. Those inserts cut you just looking at them. You start to spontaneously bleed at the fingertips.

Just about every beginner starts with crappy brazed tools, the $6/dozen jobs, and wonder why their work looks like a chimp with a hack saw and cold chisels did the job. Good work comes not only from a good machine, but also quality tooling.

+1!

As you so humorously put it, otherwise you will be monkeying around like a democrat wrapping his tail
around a flag pole so he can see his ..... Ah... Ah... What was the end of this line?

Thank you for bringing up the "Nicole "mini-thin" shank with a threading insert"
This will be the next 'must' purchase for a fugitive from TJA ... Tool Junkies Anonymous.


Remembered this old informative reference:
<< http://www.homegunsmith.com/Archive/T12928.html >>

Yeah I have pushed these tools for many years because they truly are superb for the kind of work we do. I bought the basic set because I had to do a lot of deep and fine slotting for some IC cylinder fins. They had a threading insert as well, and it was the best external threading tool I've ever used for finer pitches, say about 18 TPI or finer.

You MUST be S'in me - If you do a goggle search for "Nicole mini-thin", you get 100 images of some anorexic hollywood person. And one picture of a setup from my own shop!

It's actually "Nikcole" and there's a set on amazon for reference. Not cheap. There are Chinese clones of this set that probably are. I'd get two threading inserts and a few slotting inserts which are freaking perfect for o-ring grooves and thread relief. I haven't used a parting tool for anything except parting in a long time.

http://www.amazon.com/Nikcole-Mini-Groo ... B004KAET5I

[Historian]

Nickole "mini-thin" threading inserts in their Swiss-style tools is the cat's ass for external fine threading jobs. Those inserts cut you just looking at them. You start to spontaneously bleed at the fingertips.

Just about every beginner starts with crappy brazed tools, the $6/dozen jobs, and wonder why their work looks like a chimp with a hack saw and cold chisels did the job. Good work comes not only from a good machine, but also quality tooling.

+1!

As you so humorously put it, otherwise you will be monkeying around like a democrat wrapping his tail
around a flag pole so he can see his ..... Ah... Ah... What was the end of this line?

Thank you for bringing up the "Nicole "mini-thin" shank with a threading insert"
This will be the next 'must' purchase for a fugitive from TJA ... Tool Junkies Anonymous.



Remembered this old informative reference:
<< http://www.homegunsmith.com/Archive/T12928.html >>

Yeah I have pushed these tools for many years because they truly are superb for the kind of work we do. I bought the basic set because I had to do a lot of deep and fine slotting for some IC cylinder fins. They had a threading insert as well, and it was the best external threading tool I've ever used for finer pitches, say about 18 TPI or finer.

You MUST be S'in me - If you do a goggle search for "Nicole mini-thin", you get 100 images of some anorexic hollywood person. And one picture of a setup from my own shop!

It's actually "Nikcole" and there's a set on amazon for reference. Not cheap. There are Chinese clones of this set that probably are. I'd get two threading inserts and a few slotting inserts which are freaking perfect for o-ring grooves and thread relief. I haven't used a parting tool for anything except parting in a long time.

http://www.amazon.com/Nikcole-Mini-Groo ... B004KAET5I

My compliments to you for your perspicuity in picking up my fun 'mis-spelling' ( if the Empty Suit in Chief can misspeak
I can misspell to reference attractive young ladies ). I just ordered a set before the TJA members with nets stopped me from
sinning again.

Best.

[apd855]

I have good luck with these.

http://www.mesatool.com/products/threading-tools/

[Capt. Link.]

I have good luck with these.

http://www.mesatool.com/products/threading-tools/

Would Baffled and yourself please post your tool threads to the resource page.If you have reasons why you like this tool over another post that also.I would love to see some IC work...
Historians resource page
viewtopic.php?f=10&t=115318

[Historian]

I have good luck with these.

http://www.mesatool.com/products/threading-tools/

Would Baffled and yourself please post your tool threads to the resource page.If you have reasons why you like this tool over another post that also.I would love to see some IC work...
Historians resource page
viewtopic.php?f=10&t=115318

Certainly!

[Fulmen]

Please direct us to the inserts you would recommend

It's the ones I get for free from a friend

I've never checked the mfg or type, probably Sandvik, Seco or Iscar. I also have an internal holder from Glanze (Indian IIRC) with universal inserts that I bought from Chronos in UK that work just fine.

[Baffled]

As far as "brand" stuff goes, I have always been very pleased with Iscar. They make a series of miniature carbide-shanked boring bars that for whatever reason simply work very, very well. Their internal threading tools are excellent.

Interestingly, over the last few years, Chinese clones of various cutting tools have greatly improved. There was a day once when I'd never touch a Chinese end mill, but they are getting better. Still, they are not quite up to Western standards.

A lot of guys buy those gold "20 TICN end mills for $25!!" in the crappy wooden box, and boy do they suck. With cutters of any variety, you generally get what you pay for.