What's this metal-working doohickey?

November 14, 2012 3:58 PM

I found this metal lathe attachment? in a box that came with an old Atlas metal lathe I bought. Any idea what it is or how it is used?
posted by DB Cooper to Technology (8 answers total)

Isn't that the adjustable thingy on which you balance your cutting tool?
posted by monocultured at 4:25 PM on November 14, 2012

Husband says it looks like a taper attachment.
posted by mireille at 4:35 PM on November 14, 2012

On second look, he thinks it might be too small to be a taper attachment and that it might instead be a tool post.
posted by mireille at 4:39 PM on November 14, 2012

Husband here: Is there a corresponding opening on the machine itself? It would have to have the same TPF as the piece in question, look for a pin also that could fit what looks to me as being 1.125" opening. Without a photo of the machine, it's difficult to tell. More photos? I own a machine shop and when we switch out to new models quite often the shop hand may grab something off a bench and toss it in the box of parts to go in storage. Might not even be from that machine, if it is a part, it'll fit somewhere on the cross-slide or just behind.
posted by mireille at 5:07 PM on November 14, 2012

Response by poster: Here is a link to some additional pics of the part and the lathe. Thanks for your help!

more pics
posted by DB Cooper at 6:05 PM on November 14, 2012

Best answer: I would love to have that lathe for historical significance alone. The funny thing about a machine that size and age is that at one time that was considered to be an industrial grade machine and the capacity was something to be sought after. Machines with longer bedways and larger diameter spindle bores weren't accessible to entities smaller than an industrial revolution scaled company. This actually extended well into the mid 20th century. The Atlas models, (a cross-over of Craftsman, I believe) were one of the first models made available to small businesses and backyard machinists that was reasonably affordable with semi-dependable tolerances (0.003-0.005), these of course can be tightened up to 0.001" - 0.002" with a little time and some metal love. If you look closely at the piece in question you'll notice that the corners have been broken on all of the edges, if you look even closer you'll see how it was done with a file and that the chamfer isn't even, that piece was made by hand. We do a lot of custom, one-off work at the shop, I see tiny imperfections (or perfections, depends on the side of the fence I suppose) like that every day. The part that boggles my mind a bit is the spring or tether attached to the part, it looks like the business end of a gib clamp, (a good example of a gib would be the manually actuated clamp on the tailstock above and beyond the usual cam / lever locking mechanism found on your tailstock, in the photos you can see the bolt and nut for the tailstock gib on the bottom kind of in the center). There's also a curious pin behind the chuck (on the gearbox side) that almost looks to be the right size for the hole in that piece indicating that may have been a brake of sorts, but I ain't buying that shit. Doesn't quite fit. There's indications on the piece itself that would still support it being a toolpost of sorts, the (for lack of a better word, I fucking hate the sound of this) 'nubbin' on the bottom side has a recessed center, the recession accommodates pressure, compresses into the center and directs the force upwards kind of like a satellite array, you could think of it kind of like a hillbilly hydraulic system, I guess. I don't have an answer for you, that thing could be from anything. I wish I could tell you more than 'sweet fucking lathe dude', but - Sweet fucking lathe dude. Machines like that that have been restored and customized (chrome touches ect) sell for amounts that have no business turning up noses. Nice grab. Post-script: Don't even bother with HSS for cutting, it's junk. Keep your eyes open on ebay and buy a nice carbide holder and some inserts, you'll be astounded with the surface finish and accuracy. This is an excellent precursor for you to tell me that you're actually a machinist and I get to taste foot. Mmmm, foot.
posted by mireille at 9:08 PM on November 14, 2012 [1 favorite]

Response by poster: Thanks for the great insight! I'm not a machinist, but I am hoping to take it up as a hobby with this machine.
posted by DB Cooper at 9:43 PM on November 14, 2012

No worries. Husband out.
posted by mireille at 10:02 PM on November 14, 2012