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How does this happen to a tailstock screw?

Caesars0331

Aluminum
Joined
May 21, 2012
Location
Detroit, Michigan
I was finally able to move my 10L from storage to my shop to begin going through it, take a few test cuts, etc.

I noticed the tailstock wheel felt really 'soft' when trying to center drill a small round I had chucked up, but it wasn't until I started tearing things down did I find out why:

IMG_1817.jpg

Being new to metalworking machines, but not woodworking machines (where I've seen a lot of various abuse), I'm struggling to envision how you could deform the threads so badly. Any guesses?
 
That's lapping wear. The machine was used for quite some time around abrasives.

That steel screw runs in a bronze nut- you would think the nut would wear out, and the
steel screw would be fine. But the bronze nut gets charged with abrasive and over time
just wears out the steel screw.
 
Thanks for the feedback, guys.

Below is a picture of the threaded portion of the ram; I've read on the forum that the 10L's have a bronze nut with an acme thread pinned in the ram. Does that go for the early 10L's too? If so, it appears I have an ugly, deformed acme thread that has worn down so much that it looks more like a standard v thread?

I've never cut acme threads, so I'd need practice, but turning the rest of the screw's features are something I think I could handle. I'm nowhere near ready to try and fabricate a new ram, or even repair the internal thread for that matter.

IMG_1822.jpg

Edit: Here's a thread describing exactly what I might want to do. Too bad it's one many old threads with all dead photo links.
http://www.practicalmachinist.com/vb/south-bend-lathes/repairing-tail-stock-10l-232055/
 
"Hybridization", actually. Simply start with an under-engineered machine-tool, "vanilla" choice of materials, cross-breed abuse with persistence, multiply by time.

So in other words, physics.

For the record, I wouldn't agree that South Bends were under-engineered. They were well-engineered for a certain price point. That's why there are still so many of them around today. Not everyone needed a Maserati, er, uh, Monarch. Not that I would kick a nice 10EE out of my shop...I think it would look great sitting next to my freshly restored 1943 16" South Bend. :)
 
So in other words, physics.

For the record, I wouldn't agree that South Bends were under-engineered. They were well-engineered for a certain price point. That's why there are still so many of them around today. Not everyone needed a Maserati, er, uh, Monarch. Not that I would kick a nice 10EE out of my shop...I think it would look great sitting next to my freshly restored 1943 16" South Bend. :)

Silly to compare a SB to a Monarch or any other "heavy". Or even a "medium". Leblond Regal. Cinncy tray-top & such.

For long years essentially a "living fossil" of war-one era lineshaft designs - they were under-engineered compared to Rockwell's, Clausings, even in some respects, white-bread Logans.

Apparent durability is partly due to MOST of them being utilized in low-powered, "understressed" situations, and/or only "part time" running.

Not a lot WRONG with that. "Light work" needs turning, too, after all.

Anything pushed repeatedly to/beyond its limits will break or wear out faster than when limits are respected, and due care lavished.

OP makes a new screw & nut for this particular one, treats it as what it IS - a light-duty machine TS, not a bleedin' screw-press or drillpress - it could last his lifetime and beyond.

FWIW-even-less-department, the TS on a 10EE is the dead LAST component I'd hold up as a good example of anything Sidneyish/Monarch-istic. SHOULD be way stronger than that of a SB, not just heavier cast, but if even it is, only barely so.

Piddly 2 MT, tiny barrel & screw, thin key, chronic ball-tip breakage on the locks?

Actually the weakest "subsystem" on the entire lathe. Embarrassingly so, even.

:(
 
- they were under-engineered compared to Rockwell's, Clausings, even in some respects, white-bread Logans.
:(

With one notable exception. The lathe in question had the single largest spindle bore for that size machine, of any of the machines you mention
above.

INCLUDING the logan. Logan only made that size spindle in an 11 inch machine.
 








 
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