High-quality black-and-white photographs of large old machines and tools

[marksbug]

tin roofing dies?

[Dry Creek Smithing]

I was thinking Coragated Roofing dies as well. I'm not positive though. The size of the dies makes me wonder about something heavier. The next "Lathe" behind shows a new one in begining machining stage. I marvel at the process compared to today's machines.

[marksbug]

these days tin dies are about 4" dia, these days we know how to do lots of stuff we knew how to differently long ago.
or they could be machining tires for trains.....

[Jon]

Contouring lathe with electronic follower. Carnegie-Illinois Steel Corporation. Homestead, PA 1953.

Fullsize image: https://diqn32j8nouaz.cloudfront.net...r_fullsize.jpg

[12bolts]

with_electronic_follower

Or thats just the biggest parting tool I've ever seen!

[Toolmaker51]

Or thats just the biggest parting tool I've ever seen!

That observation is not far from reality. The good old day's before CNC...
Expanding the view reveals the tracer pattern, lower left of machinist's feet. The V has an involute-like form, so the stylus is radiused; smaller than where they converge, fillet where they meet parallel sides, and where those meet outer diameter. Many tracers are hydraulic only, depth controlled by crossfeed, first passes
don't create full contour. In mill profiling the cutter is most often ball end. Lathe work then, works likewise, with a radiused tip bit, either case is to scale of pattern and stylus. Roughing was accomplished by changing stylus or cutter size accordingly, as most patterns were 1:1, but ratios work too.
Since parting is still profiling, it's not uncommon to chamfer edges with same cutter before depth gets too far along, using the compound. best results are when [you guessed correctly] parting tool has small corner radii and square face.

[Jon]

Reconditioning a 12,000 ton press. United States Steel Corporation. 1944.

Fullsize image: https://diqn32j8nouaz.cloudfront.net...s_fullsize.jpg

[marksbug]

nowdays it's almost like everything is disposable... or if it's been there long enough it's replaced with better and old sent to aisa.

[C Tucker]

That big lathe looks a lot like the Poreba I used to run once in awhile. Ours wasn't a tracer, but it had a 60 inch chuck and was 40 feet between centers, with 2 saddles.

[marksbug]

that would wear me out just cleaning every night.