Can You Identify This Large Unusual Lathe Dog Leg?

[Metal-Masher]

Last week I posted this question in the South Bend Lathe section, but it didn't get much action there. I think it would have been better if I had posted it here instead.

I bought a group of several vintage dog legs and in the bunch was this large one. It has no markings on it.

One individual did comment that it was for transferring a work piece from one faceplate to another.

Do you know the purpose and era of this tool?

Many thanks,
Alex

 

[Jim Christie]

I haven’t seen one like that before but one thing I can think of that it might have been used for was cutting double start threads .
If that was the purpose the drive pin would have been bolted to the face or drive plate and fitted in the slot of the dog.
Once one start of the thread was cut you would back off the center and turn the work 1/2 a turn and the drive pin put into the other slot and then the second start of the thread would be 180 degrees apart from the first one.
Regards ,
Jim

 

[Paolo_MD]

As far as I know, dogs without a leg are mainly grinder's dogs, not lathe dogs.
Generally, workheads of cylindrical grinders have a stud attached to them to drive the dog. Being symmetrical is an easy way to ensure that it is balanced, both statically and dynamically.

Paolo

 

[akajun]

that looks more like a puller of some sort to me

 

[Conrad Hoffman]

Doubt it would be a puller, as it would break quickly. The screws are also typical for machinist tools. I wonder if it was for repetitive work, so you could bolt down one side in correct position, then only loosen the clamp and other side to change parts. Heck, probably something else entirely.

 

[Marty Feldman]

Not sure about how the thing would work as a puller. Looks more like a vise that could, for example, hold a puck flat on a milling machine table (or a faceplate). For such a use, however, it is not clear if the screw heads would clear the surface of the table. I see that the thing has a front and a back, the slotted tabs pocketed out on one side. Interesting item. Great precision scale in photographs 3 & 4.

-Marty-

 

[Jim Christie]

I have a couple of c. 1950 Red-E Grinder dogs by Ready Tool with two driving ends like that but they are lighter than the one in the original post.
They show one model on the lathe dog page of this site .
http://www.readytool.com/
I couldn’t find a good image of mine on line yet so I may try and post a picture later.
Maybe there will be something in this older catalogue.
READY TOOL CO. CATALOG - 1930's ~~ tools, Red-E-Tools, Bridgeport, CT - $32.99 | PicClick
Regards,
Jim

 

[art.h]

My thoughts would be For using a center on the headstock end and a steady rest, to enable doing an operation to the free end with the tailstock or boring bar. An alternative to putting a chuck on. Another reason to hold a long shaft that wants to walk out of a chuck when using a steady rest(a good indication your lathe as a twist in it and needs leveling). This would only work if your chuck had T slots, may large 4 jaws did. Like drive dogs old school thoughts.

 

[Metal-Masher]

Wow, so many different ideas. I didn't realize it was that unusual!

 

[iwananew10K]

dog for use with large dividing head?

 

[Matt_Maguire]

I was going to mention that this may be better off in general… Then forgot about it.

I have a funny feeling that is a driver that prolly came with a machine or machinery swag somewhere. It’s well built but won’t handle the power a true lathe dog will on rounds. The other two split ones look like what you’d see used with a dividing head or possibly by a tool grinder.

The 2 grinder dogs attached swing apart & assemble, 3” bent tail lathe dog for comparison. The 4" split dog originaly had cap screws like the 2.5" one does but they plum wore out so I made studs & hex nuts for it...

Good luck,
Matt

 

[Jim Christie]

Attached are some of the grinder dogs in my collection .
You can see the 2 Red-E dogs in the boxes with two driving lugs .
I have used them a couple of times and they had little if any use before I got them with a machine I bought.
The others either came with machines or are some I found in a box at a dealer's
Regards,
Jim

 

[Metal-Masher]

Attached are some of the grinder dogs in my collection .
You can see the 2 Red-E dogs in the boxes with two driving lugs .
I have used them a couple of times and they had little if any use before I got them with a machine I bought.
The others either came with machines or are some I found in a box at a dealer's
Regards,
Jim

Jim- Your Red-E grinder dogs look very similar to the one in question. Thanks for posting those photos.

I hope that someone can zero in on the manufacturer and era, if at all possible. Tough to do without markings, I know.

In this thread you can see that as more time goes by, the trail grows colder. For me personally, I like to look for the history of odd things like this dog, then I tag the items with what I know. It may seem a bit anal, but its a good way to retain the knowledge of our history, which is so often lost to apathy.

Alex

 

[iwananew10K]

ya, about the only way it seems good for lathe work would be a scenario for large,heavy work between centers withou tail stock support(like with a steady rest) where just lashing would not be enough pull the work tight to chuck or faceplate.

 

[JST]

Well, now I know that one grinder dog I have is probably a Red-E. Just like those.

 

[CBlair]

Art H beat me to it, this would be used when driving a shaft from the center with the free end in a steady rest. Similar to strapping the barrel of a rifle if your spindle hole isnt large enough to pass the barrel through. There are illustrations in older gunsmithing books that show something similar. Dont know if they are online or if I can find the photo now. Another method was to use a metal strap around a regular dog and bolt it to the face plate.

Charles

 

[CBlair]

Well, now I know that one grinder dog I have is probably a Red-E. Just like those.

I have one of those also, somewhere?

Charles

 

[Marty Feldman]

Jim Christie's Ready dogs are convincing. Paolo_MD back in post #3 got it.

-Marty-

 

[Jim Christie]

There is some discussion about bent and straight tail Lathe dogs starting here .
International Library of Technology: A Series of Textbooks for Persons Engaged in the ...
Farther on they discuss two tailed and equalizing lathe dogs.
This volume doesn’t work so well for me in the single page view but there maybe another copy on the Hathi Trust site or Google Books if they work better for you .
I have a print copy of this book although it may be a different edition .
Regards,
Jim

 

[Matt_Maguire]

Jim, those dogs look beautiful, collection quality IMO.

Yes the bent tail lathe dogs can make your work cork screw if you finish cut heavy. They were known for actually being strong enough in grip to break the cast iron back gear teeth in the old days of belt & sheave lathes…

Good luck,
Matt