threading away from the shoulder - a tool to consider

[savet06]

I know that this topic has been discussed ad nauseum, but I haven't seen mention of this tool before and wanted to share my experience with it.
If you go to ebay.com and search for "goose neck threading tool" you will find the 1/2" shank tool made by mesatool based in the U.S., though I am not sure if the machining of those tools is done here. Does say country of manufacture USA on ebay.
an image:
https://i.ebayimg.com/images/g/kN0AAOSwC4FdVeB8/s-l1600.jpg

I have not seen this tool on mesatool.com's website though they have a really interesting set of threading tools that would allow the same type of threading with a different insert.
The goose neck tool allows the use of the arthur r warner HSS tnmc or similar inserts to be used upside down and at the proper center height. I have a 40 position tool post and would have to shim the 1/2 shank regular left hand tool too high for use on my machine, an emco v13. I had some issues with trying an internal threading tool on the back side of the barrel and decided to try this.
I have threaded my first barrel with it, and it all went very well with an excellent surface finish. I have recently started threading away from the headstock, and start by making a 60 degree groove at the shoulder to full thread depth. I have also recently had to advance the shoulder of a barrel about .250, and the groove I made allowed the thread to continue seamlessly even while threading away from the shoulder.
For use some-timers this tool may be a great addition and at about $40 was worth it for me. YMMV
Mike

 

[jackie schmidt]

Pretty neat tool.

 

[bapayton]

Interesting tool. Wouldn't mind trying it in 5/8 shank.


I have one of Mesa's 1/2" threading & grooving tools. The inserts are so fragile I quit using it almost right after I bought it, at least for external threading. This one looks much more functional.

 

[Pete Wass]

Ive watched several Youtubes

on threading away from the head stock and do it myself, most often. I also have seen some Ausies and Europeans who never take the machine out of the half nut once they begin their thread. I tried that the last barrel I did and it worked great. My lathe has a sloppy or lagging half nut so this was very beneficial to me. Helps to have a machine with a brake, which mine doesn't . I've used HSS threading tools all the while I've been doing this except for once. I bought a Carbide threading tool and got a big ball of chips. I spoke to a tooling guy about it and he said he didn't use carbide for that reason. I don't have coolant and that may make a difference but it would seem to me that carbide not performing at slow speeds well would be the reason for the issue.

Thoughts?

Pete

 

[GeneT]

on threading away from the head stock and do it myself, most often. I also have seen some Ausies and Europeans who never take the machine out of the half nut once they begin their thread. I tried that the last barrel I did and it worked great. My lathe has a sloppy or lagging half nut so this was very beneficial to me. Helps to have a machine with a brake, which mine doesn't . I've used HSS threading tools all the while I've been doing this except for once. I bought a Carbide threading tool and got a big ball of chips. I spoke to a tooling guy about it and he said he didn't use carbide for that reason. I don't have coolant and that may make a difference but it would seem to me that carbide not performing at slow speeds well would be the reason for the issue.

Thoughts?

Pete

I have found a few carbide inserts that work well for threading at low speed*, but I tend to use HSS most of the time as well. I'm curious about the benefit of leaving the half-nut closed. I'm pretty sure it makes no difference if you're threading toward the headstock - in that case the backlash is taken up before the cutter touches the work. If one were threading away from the headstock I think it would depend on how you approached getting back to 'start', but perhaps not.

GsT

*Shars 424-1381, 424-0797

 

[Michael Huebner]

I have found a few carbide inserts that work well for threading at low speed*, but I tend to use HSS most of the time as well. I'm curious about the benefit of leaving the half-nut closed. I'm pretty sure it makes no difference if you're threading toward the headstock - in that case the backlash is taken up before the cutter touches the work. If one were threading away from the headstock I think it would depend on how you approached getting back to 'start', but perhaps not.

GsT

*Shars 424-1381, 424-0797

I would suspect his reference to half nuts being engaged will be metric leadscrew machines cutting imperial threads

 

[jackie schmidt]

I would suspect his reference to half nuts being engaged will be metric leadscrew machines cutting imperial threads

Correct. If a machine has a imperial lead screw, you generally have to leave the half nuts engaged to cut metric, and visa versa.

We have five late model lathes in our shop that cut both, and that is how we have to do it. And yes, it helps to have a good brake.

 

[Pete Wass]

Now that you mention it

I would suspect his reference to half nuts being engaged will be metric leadscrew machines cutting imperial threads

Those folks were doing what you said. Figured they would have done it anyway, regardless of what thread they were cutting. In my case, my half nut isn't reliable. Also, I recall Joe Pi showing a recent Youtube where he kept his half nut engaged whilst threading away from the chuck while threading US threads. They always take the backlash out before proceeding to the next cut. For we hobbiests and home shoppers, these youTubes are priceless. I understand it's likely boring for someone who has been a machinist all their lives but for many of us who learn best by watching, these episodes can't be beat.

Pete

 

[rsmithsr]

not sure what "backlash" you are refering to.
in threading, you engage the half nuts at the same basic spot on the shaft, and the shaft rotation removes any backlash, before any cutting happens.

Those folks were doing what you said. Figured they would have done it anyway, regardless of what thread they were cutting. In my case, my half nut isn't reliable. Also, I recall Joe Pi showing a recent Youtube where he kept his half nut engaged whilst threading away from the chuck while threading US threads. They always take the backlash out before proceeding to the next cut. For we hobbiests and home shoppers, these youTubes are priceless. I understand it's likely boring for someone who has been a machinist all their lives but for many of us who learn best by watching, these episodes can't be beat.

Pete

 

[Pete Wass]

Backlash in the lead screw

not sure what "backlash" you are refering to.
in threading, you engage the half nuts at the same basic spot on the shaft, and the shaft rotation removes any backlash, before any cutting happens.

Unless one has an absolutely tight half nut and unworn lead screw, there will be backlash. If it isn't allowed for or allowed to be removed, things can go wrong. Watch one of Get er out's vids where he threads without releasing the half nut, he explains about the backlash. I see it in my lathe so I take it out before I proceed each time. If you had read about not releasing the half nut, you might understand better.

Pete