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South bend 11 through hole enlargement

Brodytonelotti

Aluminum
Joined
Feb 8, 2017
Location
Hocking Hills
Well I have a 11" south bend from 1927 and just put a variable speed and reversible D.C. Motor on it. When they drilled the hole through the spindle there bit walked and the end of the hole is out about 1/8 of an inch. I have been kicking around the idea of making a new spindle for it and I think I can squeeze a 1 1/4" through hole out of it without having to change any of the gear train and I would still have a 1/4" wall. The lathe is in really good shape and if I can make the spindle hole larger I will go ahead and use it for gunsmithing. I know a heavy 10 or something larger would be better but I got a really good deal on this lathe and don't mind putting some work into it. I just wanted to see if anyone has ever tried this on an 11 or any other lathe. I could also use some parts if anyone has any laying around. Thanks
 
Those early lathes have soft spindles, so it could be done. That said, what sort of stress will be released when you start cutting, and will that distort the spindle? Also, I would assume the original spindle was bored after it was drilled, so are you sure you don't have something bent already? Pictures would be good.

allan
 
Well I have a 11" south bend from 1927 and just put a variable speed and reversible D.C. Motor on it. When they drilled the hole through the spindle there bit walked and the end of the hole is out about 1/8 of an inch. I have been kicking around the idea of making a new spindle for it and I think I can squeeze a 1 1/4" through hole out of it without having to change any of the gear train and I would still have a 1/4" wall. The lathe is in really good shape and if I can make the spindle hole larger I will go ahead and use it for gunsmithing. I know a heavy 10 or something larger would be better but I got a really good deal on this lathe and don't mind putting some work into it. I just wanted to see if anyone has ever tried this on an 11 or any other lathe. I could also use some parts if anyone has any laying around. Thanks

Just a guess, but it might be less total work and risk, better outcome if you fitted an entire HS to it, spindle, bearings, drivetrain, 'modern' RPM capability to utilize carbides better, and all.

Personally, I'd just go and get better-suited lathe.

These 'Frankenprojects' tend to get slow to complete, more expensive than planned, too often just die along the road rather than ever deliver to goal.
 
Those early lathes have soft spindles, so it could be done. That said, what sort of stress will be released when you start cutting, and will that distort the spindle? Also, I would assume the original spindle was bored after it was drilled, so are you sure you don't have something bent already? Pictures would be good.

allan
I don't believe it is bent already. You can see at the back of the headstock that the hole is off center. I'll try to take a picture of that this weekend but for now I'll post a few general pictures of the lathe itself
 
Just a guess, but it might be less total work and risk, better outcome if you fitted an entire HS to it, spindle, bearings, drivetrain, 'modern' RPM capability to utilize carbides better, and all.

Personally, I'd just go and get better-suited lathe.

These 'Frankenprojects' tend to get slow to complete, more expensive than planned, too often just die along the road rather than ever deliver to goal.
I'd like to keep it as original as possible so I don't really want to try to fit a modern HS to it. It would just look weird to me. I would like to eventually get a larger lathe. At least a 13" and a large Bridgeport mill in the future but I like a good challenge and would like this lathe to work in the mean time as it's not currently used to make me money so I can't justify getting another one yet
 
I don't believe it is bent already. You can see at the back of the headstock that the hole is off center. I'll try to take a picture of that this weekend but for now I'll post a few general pictures of the lathe itself

That surely sounds more as if you are looking at a spindle that is ALREADY some Pilgrim's DIY shop-fab or at least flawed modification.

1927 was 'fat times' for most manufacturers. War One was nearly ten years behind them, surplused machine tools left-over from it finally being used up, economy was in high-gear with the crash of '29 still in the unexpected future?

No Fine Way QC would have been likely to let that pass AT ALL when the most common collet-closer of the era - and common they were - was an arse-end handwheel that NEEDED decent concentricity and would have led to a serious stink being raised were that to be impaired.

If that spindle was ever OEM, it has been f**ked with, post-production and delivery.

Doesn't happen to be oversize vs factory spec does it?

:)

Oh.. and DO please confirm you speak of the rotating item - the spindle itself - AND NOT the difference between the spindle axis and that of a clearance hole in a cast-iron cover?
 
That surely sounds more as if you are looking at a spindle that is ALREADY some Pilgrim's DIY shop-fab or at least flawed modification.

1927 was 'fat times' for most manufacturers. War One was nearly ten years behind them, surplused machine tools left-over from it finally being used up, economy was in high-gear with the crash of '29 still in the unexpected future?

No Fine Way QC would have been likely to let that pass AT ALL when the most common collet-closer of the era - and common they were - was an arse-end handwheel that NEEDED decent concentricity and would have led to a serious stink being raised were that to be impaired.

If that spindle was ever OEM, it has been f**ked with, post-production and delivery.

Doesn't happen to be oversize vs factory spec does it?

:)

Oh.. and DO please confirm you speak of the rotating item - the spindle itself - AND NOT the difference between the spindle axis and that of a clearance hole in a cast-iron cover?

Yes. The through hole in the spindle compared to the OD of the spindle itself. The through hole is 7/8 and that was spec so it isn't oversized. It may be a spindle someone made because when I take the bushing off the spindle is grooved and marred so it must be a fairly soft spindle. The spindle does run pretty true though so if somebody made it as a replacement they did a decent job with concentricity.
 
Yes. The through hole in the spindle compared to the OD of the spindle itself. The through hole is 7/8 and that was spec so it isn't oversized. It may be a spindle someone made because when I take the bushing off the spindle is grooved and marred so it must be a fairly soft spindle. The spindle does run pretty true though so if somebody made it as a replacement they did a decent job with concentricity.

It is actually a dead-easy turning job, especially if you have at least borrowed access to a much better lathe to do it on than the fossil under repair.

Challenge comes when you DO go to harden it, make it 'right' for whatever sort of bearings are to be fitted.

If you choose to do it on the lathe you have, plan to make TWO.

First one need not be hardened, won't even need 100% of the 'features', nose threads, through-bore, internal taper, and back-gears can all be left-off, for example.

Just put a 60-degree point right onto it, cross-drill for a pin to drive a dog, and work 'tween centers. HS end turns WITH the work, takes less stress than TS end.

It should be as accurate as you can make it bearing, end-play, ergo TIR-wise.

Use that one to make a much better one, even if it takes more than one go to have it good after cutting ALL the features, hardening, and selective grinding. You'll have to use a decent drillpress, then reconfigure the lathe as a half-assed boring machine, too, but that is also done 'tween centers. And damned slowly.

Worn bed, carriage, cross, TS - everything, really - make that a series of 'compensating' workarounds, but lots of folk have had to deal with that and done it well with 'patience' their best tool.

Other than as a confidence-builder, not really worth it, BTW.

Not for a very average mass-produced lathe.

Count up the operations and how you will have to deal with each, perhaps you'll see my point in not even starting down that road?

Better to just run what yah got, apply the time and effort towards earnings for a better machine altogether.
 
It's not even worth posting about, How are you going to drill the new spindle with that short bed?

Don't drill, bore. Setup an outboard support, clamp a long, counterweighted bar in the toolpost, and drag it. You'd have to drill in place, which might shift the work some.

Also, the spindles on these lathes were dead soft from the factory. Show some pictures of the spindle nose too, they were generally very nicely machined, with a ground OD. That should help identify if it is the original spindle.

allan
 
It's not even worth posting about, How are you going to drill the new spindle with that short bed?

I've got store-bought drills two and three times the length of that spindle that are about the right size to get the initial bar clearance. Walker-Turner here would need about three changes in drill length. AB5/S would need one change.

That could be done on the lathe he has, drill in spindle, two stages, mebbe but one.

OTOH, the longest store-bought drill I mentioned probably cost twice what he paid for the whole lathe, so "to be fair".

A person needs to know how to make "D" drills. Those are cheap enough, any length needed.

Lots of folks as would be gobsmacked, they watched a Pennsylvania long rifle barrel being hand made and 'hook' rifled, late 1700's. Then were shown there were more than two ways of making barrels, already. And on how much local hardwood - not even metal - was involved in the doing of so much of it.

I did say something about the whole project taking a good deal of time and patience?

No such thing as "can't".

Just "How serious are you about wanting _____?"

"Man is a tool MAKING animal" after all, so if there "is no way", we MAKE a way, and in as many stages as it takes to 'bootstrap' from cold start to the desired end.

:)
 
Most any kind of drill, gun drill or reamer would follow the hole that is off center..

Guess you might grind the back end ID to a size perhaps 1", 1 1/8" or even 1 1/4" if you trust going that large to a depth of 1" or 1 1/2". then press in a bushing to be the out-board bushing for a line bore boring bar. Yes a brass, or bronze bushing with an oil drip hole might be good..

*Part of the need for wall thickness is that the weight of the chuck and work piece.. perhaps out of balance is a big load to swing..so I might not reduce it to 1/4 wall.

Yes with having another lathe to use you could make the bushing bore with part held a steady and bore. yes the opposite end in a 4jaw or the like.

Stresses have already been taken out and put in with the off center drilling
 
Most any kind of drill, gun drill or reamer would follow the hole that is off center..
Only if you allowed it to do.

If the original spindle was to be improved with nothing more complicated that a length of torch-hardenable drill-rod, Job One wold be simply to set an undrilled slug into it, bore a pilot hole that WAS true, and put a pilot onto the nose of yer shop-fabbed "D" drill to guide on that, not the original bore it was filling.

Nothing remotely 'new' about that.

The technique for 'moving a hole' to a different centre works with dirt, wood, bone, and stone as well, so may have started before we got to messing about with metal at all.

:)
 
Agree to that..perhaps the slug in the error end and re-centering from that end.. good idea.

Still going in the nose end or the far end perhaps a 7/8 diameter home made drill might have difficulty going 20" deep in to a hole that ran off at the deep.. I have deep drilled with single and double flute Gun drills having .0002 back taper with good success.
Some jobs that deep I would do the bore first and then finish the OD last, cant do that with this job :)

Yes I should go down to see how Kenny Jarrett does his barrels so well.

OT: with not having a radial relief fixture on can put on a facet grind 10 t0 12* clearance then butter fly round the heal..single or double flute. Yes with centers or in a bushing.
 
OK, if you were marooned on an island somewhere and it was all you had you could figure out a way to do it. But your not so why bother with it, especially on an old sb. I don't see why atlas is banned and sb is not. Just get a real lathe and be done with it.
 
OT: with not having a radial relief fixture on can put on a facet grind 10 t0 12* clearance then butter fly round the heal..single or double flute. Yes with centers or in a bushing.

Lots of ways to do most things.

"Hacker's Second Law" applies. Mind - I'm not sure I've been all that consistent each time I proclaim it, but you'll get the drift, 'coz nothing *I* do is 'original', either:

There are few things TRULY new under the sun.

When faced wth a new challenge, Job One is to ascertain how the most-recent SUCCESSFUL entity handled that same challenge or one like it.

THEN see if their method even needs improvement.

Whenever you feel you have done something for the first time, ever?

Don't get TOO damned cocky. It usually means you just didn't do your research. There's "prior art" to some degree or another for most everything.

:)
 
[Don't get TOO damned cocky.] I do hope I did not seem too cocky..
Just throwing ideas out there like everybody .:)

Oh, no... not you! Mankind in general. I mean..

Well... Saturn Five was one hellacious impressive bit of rocketry. Moved itself by expelling mass out its arse at a higher velocity than average.

So does a common Squid. Same basic concept.

And Squid have been around for 'at least 60 million years'. Nary an Aerospace Engineer or machinist - that we'd recognize on-sight, by OUR metrics, anyway - involved in their reproduction then, before, or until present-day.

:)

BTW: Google "Mantis Shrimp" for some far, far, more impressive "technology".
 








 
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