What exactly is this piece of equipment?

[jtrout13]

I was looking at various things on Wikipedia and stumbled across the following picture, and wondered what it is. Obviously I know it is a US Navy seaman working on a lathe, but I don't know what the thing is he has mounted on his compound rest. I found a wooden box in the corner of our shop this morning which had one of these things in it, but nobody around seemed to know what it was, and there was no print on the crate it was in.

I'd appreciate any answer you could give me. I'm studying mechanical engineering, but machining is my first love. My summer job has me working 40hrs a week in the machine shop building stuff for research projects, so I'd like to learn all I can about it.

 

[Ed T]

Ball turning tool holder. He's swinging the tool with the braker bar.

 

[milotrain]

[youtube=425,350]http://www.youtube.com/watch?v=f4pwUw0G3RQ[/youtube]

^Video

 

[rkepler]

It's a Holdridge ball turning attachment.

http://www.holdridgemfg.com/

 

[1Kenny]

Great reply Guys.

 

[Tin Falcon]

Yep commercial ball turning tool. there are many shop brew variations of this tool .

My summer job has me working 40hrs a week in the machine shop building stuff for research projects, so I'd like to learn all I can about it.

J see if your shop has an msc catalog and or a McMaster Carr catalog. Browse through these on breaks and lunch time.
This thread has lots of links to reading material.
http://www.homemodelenginemachinist.com/index.php?topic=9413.0
Also scan the web the various manufacturers have things you can download pdf files of. many are catalogs but the catalogs often have info of how to best use there tools. and guide selection.

Tin

 

[jtrout13]

Thanks guys, I have a small ball end I want to turn for a project, but I've been doing it with files and emery before I found this out. I'm excited to give this thing a try!

 

[n4zou]

I know it is a US Navy seaman working on a lathe

He's not a seaman, and he would get mad at you if you called him that.
He's a Fireman. He is a non-commissioned 3'rd class petty officer (E-4). Note the colour of the stripe under the eagles on his collar. The red strip denotes that he is a Fireman. White stripes denote a seaman and green strips denote an Airedale.

Build your own ball turning tool.
Free Plans: Ball Turning Tool Post for the 7x Mini-lathe
http://www.machinistblog.com/free-plans-ball-turning-tool-post-for-the-7x-mini-lathe/

If you have a larger lathe you can scale it up in size to fit.

 

[MachineTom]

Inside the wooden box, the instructions should be glued, If not post a request, or drop me a PM and I'll walk you through it. Everything is simpler once you know how.

 

[jtrout13]

Thanks for the replies guys. I'm aware that the person pictured is a Fireman, in fact I've been asked to study at the USN Nuclear Reactor school post graduation. I just used the term seaman as a general term, similar to the term 'soldier,' since I've noticed this board has many members from around the globe which might understand the term better.

 

[Maryak]

From my association with the USN, I thought he was a Machinists Mate or has that term disappeared ???

Best Regards
Bob

 

[Omnimill]

Thanks for the replies guys. I'm aware that the person pictured is a Fireman, in fact I've been asked to study at the USN Nuclear Reactor school post graduation. I just used the term seaman as a general term, similar to the term 'soldier,' since I've noticed this board has many members from around the globe which might understand the term better.

Lucky you said it otherwise I'd be asking why the Fire Station has a machine shop! ;D

Vic.

 

[jonesie]

just my opinion, as i was in the navy and in r div, and my bet is that he is an mr machine repairman and could be on any ship from a destroyer to aircraft carrier to a tender.nice piece of tooling when you learn to ste it up, as you can do both male and female radius, learn to us and have fun. jonesie

 

[ChooChooMike]

ball-turning attachement

Wouldn't the correct term be "Radius-turning/cutting attachment" ? since it can be used for cutting inside and outside radii

 

[MachineTom]

The correct name is a spherical turning attachment, since its used in a lathe, items will come out with a 3 dimensional sphere, or segment thereof, not a 2D radius. The manufacture Holdridge calls it a Spherical Turning Device.

 

[mklotz]

The correct name is a spherical turning attachment, since its used in a lathe, items will come out with a 3 dimensional sphere, or segment thereof, not a 2D radius. The manufacture Holdridge calls it a Spherical Turning Device.

Mathematically, spheres are described by a radius. It's not a strictly two dimensional descriptor.

 

[MachineTom]

So after posting that Holdridge calls it a Spherical Turning Device, Marv correctly says a Radius is 3D, I open my Holdridge Tool box. Having used this thing for a couple of years, it did not dawn on me the they named this thing "Radii Cutter" Yup the Old brain ain't what it used to be

 

[mklotz]

In fact, hyperspheres (spheres in spaces with greater than three dimensions) are described by radii too, although I doubt the average "Radii Cutter" can make one.

 

[Rayanth]

In fact, hyperspheres (spheres in spaces with greater than three dimensions) are described by radii too, although I doubt the average "Radii Cutter" can make one.

Marv's apparent wealth of knowledge is making his avatar picture a bit more meaningful ;D

- Ryan

 

[DavesWimshurst]

One could also make toroidal (doughnut) shapes using such a tool. Handy for the top of your Tesla coil, or if you're a topologist a starting point for a coffee cup :
Dave