Another auto retracting tool holder

[BoydAllen]

 

[jackieschmidt]

With something like this, perhaps the best thing to do is just let the video speak for it‘s self.

 

[shortgrass]

I think he needs to stick the work piece further out of the chuck!! Dang!

 

[tobnpr]

Well, interesting idea...but
Requires straight-in feed with the cross/compound. Not an ideal way to thread, cutting on both flanks of the insert-especially with coarse threads.

The "kickout" lever on the toolpost is angled. As he feeds in with the cross the "stop" mounted on the way will contact it at a different point (earlier) than the pass before. I don't see how that works with coarse threads with deep DOC.

Rigidity...curious how that thing is actually put together. The toolholder is sliding, which means clearance.

To me, it's a solution looking for a problem. Perhaps there's an application for it somewhere but not for moi.

 

[spitfire_er]

For general threading, I like the idea.

 

[tobnpr]

Isn't it disconcerting when you look at something online...then Google starts bombarding you...

This popped up on Youtube, this guy really put some work into it.

If you wanna cut threads at 1000 rpm on a manual lathe, guess this is the ticket

 

[shortgrass]

For general threading, I like the idea.

What is "general threading"?

 

[Dusty Stevens]

What is "general threading"?

Not specialty or “trick” threading

 

[shortgrass]

Not specialty or “trick” threading

If that's all "general" is, I'll stick with the convention methods. So, what's 'trick' threading? Heck, I thought single point threading was just that, single point threading. Any 'tricks' I tried made me crash! A device like that shown in the two threads just wouldn't be worth my time to make.

 

[Dusty Stevens]

If that's all "general" is, I'll stick with the convention methods. So, what's 'trick' threading? Heck, I thought single point threading was just that, single point threading. Any 'tricks' I tried made me crash! A device like that shown in the two threads just wouldn't be worth my time to make.

You still gotta disengage the carriage or itll still crash pretty quickly. Id love to be able th thread to a shoulder at about 900rpm

 

[Gun Smith]

My Hardinge HLV-H has a dog clutch(?) that kicks out the feed for threading to a shoulder. Somewhere in the manual it has a warning about threading at 1000 rpm if I recall. Never tried near that fast, too chicken!
I stuck with 3-4 rpm, and was comfortable. Haven't threaded anything in a couple years now, so I'd have to
retrain my brain!

 

[spitfire_er]

What is "general threading"?

Anything that doesn't require critical specs. Don't overthink it. 1A or 1B vs a 3A or 3B class thread.

 

[Danny1788]

I’ve seen the proximity switch used a couple times and that seems easier and would be more ridged in my mind, since it completely stops the lathe.

 

[shortgrass]

Anything that doesn't require critical specs. Don't overthink it. 1A or 1B vs a 3A or 3B class

Anything that doesn't require critical specs. Don't overthink it. 1A or 1B vs a 3A or 3B class thread.

Ahhhh, but Dusty said " not specialty or trick threading". I see nothing "specialty" about class 3 threads. They're cut every day. I see nothing 'trick' or "special" about threading.

You still gotta disengage the carriage or itll still crash pretty quickly. Id love to be able th thread to a shoulder at about 900rpm

On a 1 1/16 diameter, that calculates to 250SFM. You can run carbide faster than that! But as you point out, you still have to dog out the carriage. Yesterday I cut a Hart that goes on a 700 @ 300RPM using a 1/2" HS bit (83 sfm by calculation). No crashy. By the time the gadget could be set-up, you could easily be done threading a barrel tenon conventionally.

 

[akajun]

There was a commercially made device like this called a snap tap, I think it was made in Europe. A retired machinist that did oilfield work had one and offered it to me
he showed me a few videos he made and said he could use it to thread To a shoulder manually at high speed and get great surface finish on his threads
he wanted 600 and I should have bought it

 

[tobnpr]

If I needed speed for a short production run of widgets, I'd use a die head and not single-pointing.
Different ways to skin that cat too.

 

[butchlambert]

I’ve seen the proximity switch used a couple times and that seems easier and would be more ridged in my mind, since it completely stops the lathe.

Nez, Bamban,on this forum built his own proximity switch to thread at high speed.

 

[Gun Smith]

Nice video tobnpr, thanks for linking it here. I have a geometric die head like that, that I used to use years back for making hundreds of special 5/16 -18 aluminum knurled bolts about 5/8" long on my South Bend with a 6 station turret. Worked like a charm. Sure beat a standard round die. Whomever invented that die head was a genious!

 

[shortgrass]

We used self-opening die heads on screw machines and turret lathes. Want to see 'genius'? You should watch a multiple spindle automatic bar machine run for awhile.

 

[Dusty Stevens]

We used self-opening die heads on screw machines and turret lathes. Want to see 'genius'? You should watch a multiple spindle automatic bar machine run for awhile.

I can still see the wall of cams in my sleep