Mystery piece of tooling? Lathe?

A variation on this style of threading tool?

It looks to me like a formed threading tool:

Is the disk cut to the right shape and hardened?

jsw

Yeah, the circular piece looks like a circular threading tool, which is a type of circular form tool. But I don't understand the holder.

Ignoramus14657 fired this volley in news:mO-dnZP5N6qSwvvWnZ2dnUVZ snipped-for-privacy@giganews.com:

Guys, awl... If it were a threading tool, doesn't it make sense it would have to move with the carriage? It _clamps_ to the ways. If it didn't clamp, it would fall off, as the front of the way is square, not dovetailed.

LLoyd

I wondered if it was a stop of some sort. Rotating the circular "tool" part would allow it to stop against or allow to pass a stop that was mounted to the carriage.

I am with Lloyd. If it was a threading tool, I do not see how it would clamp to carriage -- but it clamps to bed very precisely.

i

Maybe it is in some way related to the taper attachment. I will look more today.

i

It also isn't a 60 deg profile, like you'd expect for a threading tool. It appears to have a little flange.

If it had a through hole along the bed axis, I would have bet on the taper attachment clamp which I haven't seen in Ig's pics.

Right now I have no idea what that thing does.

Pete Keillor

Clamped to the front of the bed, it's a carriage stop.

It certainly looks so much like a form cutting tool for a thread (not a

60 degree thread, as has already been pointed out) (or particular groove) that I can't imagine it being anything else. The bed-edge clamping is probably a side effect of some quick-change tool-post that didn't catch on - it might well fit the back end of a typical lantern toolpost bit holder, for instance, just as well as the edge of the bed.

Also, clamped to the edge of the bed, the large bolt hole through it is not in use - the "clamp" screws are probabaly for fine positioning, while the main attachment bolt is supposed to be in that empty hole.

...and the side facing "out" from the late bed should be facing "Up" from the compound - with a T-nut in the compound that sticks the tail of the T above the surface of the compound for the slot to engage.

I don't believe that this is intended to mount on the bed of your lathe. I think you have a form tool that is mounted into a tool holder for some sort of screw machine. When Gunner gets back from dismantling America's industrial infrastructure, he can probably give you a better idea.

Paul K. Dickman

looks like tooling for a screw machine. cutoff tool for a cross slide. to sharpen you just grind the cutting surface and rotate it a little in the holder to make up for what you ground off.

Pete

No, it just appears to be sitting on the end of the lathe carriage. It has a dovetail that I assume mounts to some form of QC toolpost.

Jon

I am convinced by responses on practicalmachinist, that this is a circular form tool. It it basically a cutter that cuts profile on its edge. When it becomes dull, a little bit is ground off from it to expose new surface.

i

Like so many things mechanical, it's a mystery to me, too. If the talent here doesn't offer a good explanation, you might follow up by hawking it on ebay, set the shipping cost high-ish. If you get a buyer, ask HIM/HER what it is.

Yeah, that sounds right! I knew I'd seen stuff like that before. I also agree that if it fits the lathe bed, that is just a complete accident.

Jon

The "wheel" part is a threading cutter. It is resharpened by grinding back along a radial line, loosening the big nut, and rotating it to restore the radial line to center with the spindle axis prior to re-tightening the big nut.

I'm not sure what kind of toolpost it mounts on, but certainly not on the edge of the bed as you have it shown.

I'm not sure what the other bright metal piece is for -- but at a guess, it is an extra cutting edge to bevel the end of the workpiece so you can do two parts of the task with a single tool

It would be interesting to see what it was actually supposed to mount on. Obviously, not the piston style quick-change toolpost which the machine currently has mounted.

It might be for mounting on a turret tool -- but that would require a power feed for the turret, not the bolt-on bed turret that my Clausing has. For my turret, the proper tool for threading is a Geometric die head -- or one of the similar ones from other makers.

Enjoy, DoN.

Maybe it clamps to a square shank to be held in the standard tool holders? And maybe the thickness of the bed just happens to be the same size as the shank?

The fact that it clamps on the bed is a red herring -- or at best a coincidence.

Enjoy, DoN.