Need advice for repairing damaged SB 14-1/2” lathe

[rwdenney]

I posted in another thread about the tumble my new SB 14-1/2 took when it turned over removing it from the skid. I know I’m new with little credibility on the forum, and what I’m needing may need old-friend status with some of you. I get that, and wish I had time to earn more respect here, but this is the hand I dealt myself when I let the lathe tip over.

Now I’m trying to put the toothpaste back in the tube.

The taper attachment slide block (6 on the diagram shown further down) and the bed bracket (28) are destroyed, broken into several pieces. Those parts are cast iron and brittle (the photo doesn’t show it, but one of the dovetails from the slide block was snapped off—it’s sitting in its correct spot in the photo).

Another victim is the crossfeed screw, which buckled into a camel hump:

The brass nut still turns on the screw, but I already have a new nut in hand. The nut retainer hollow bolt broke as well. I’m assuming at present that the front part of the slide shaft is undamaged, or at least repairable with new thrust bearings.

The connecting bar (4) was distorted and is out of flat by about 1/16”.

The saddle took some damage but not fatal. One connecting bar bolt blew out a chunk of the casting, but most of the thread is still there and I can epoxy a stud in its place. And one gib bolt on the back of the saddle broke, and the other two bent, but the gib is undamaged and the bolts are common. The gib held and I believe prevented further damage to the saddle, which still moves smoothly on the bed.

The binder stud (5) that locks the connecting bar is broken. But the sleeve (21) is fine.

Here is a parts diagram with broken parts circled:



Options:

1. Find a replacement taper attachment with screw. Obviously, this is the preferred course but they are not thick on the ground. (More expensive alternative 1a is to fabricated the broken parts from steel, but I expect that would be pricey).

2. Replace the screw and the bed bracket only. The bed bracket is necessary for the taper attachment screw, because that screw is only keyed to the power-feed spur gear on the cross slide shaft, and depends on the thrust bushings in the taper attachment to retain it into that spur gear.

3. Convert the lathe to a non-taper version. This would require a new cross slide shaft/screw all the way out to the handle, with the threaded portion fixed in the spur gear instead of a keyed insertion. Then, the bushings at the handle end do all the thrust work. Alternate 3A—find a 11/16-8 LH Acme threaded rod and pin or braze it into the spur gear. That would close the door on a future restoration of the taper attachment.

4. Modify a 16” taper attachment to fit. The 16 uses the same 11/16-8 LH Acme thread as the 14-1/2, and presumably only differs in length. If the 16 taper attachment could be mounted in a useful location, I suspect the screw could be adjusted to fit. The connecting bar wouldn’t fit on the slide, but maybe I can machine flat my old one and make it work. I’d need someone with a 16 taper attachment to measure it up for me so I could understand the differences.

5. Use a SB 16 screw and fabricate enough of an outer bracket to install a thrust bushing to retain the screw. No taper attachment, but might be easiest. I’d need help from a machinist willing to fab up that bracket, but I am sure I could provide a good drawing. This would preserve the ability to restore the taper attachment in the future.

I’m hoping against hope that someone is parting out a 14-1/2 Toolroom model and still has the basic taper attachment parts.

Ideas? Advice? First priority is to get it working without the taper attachment.

Also needed: a carriage stop for the 14-1/2. I had ground down one from a 16 that worked, but the carriage was locked when it fell and this part broke.

Rick “asking a lot” Denney

 

[Dabbler]

Rick, it really sucks that you had this happen. I'm very sorry for the path you are now following...

Let me start with a bias: I have a taper attachment on 2 of my 3 lathes, and in 40+ years of machining, I've never used either of them.

I think option #3 is your best bet for the short term, and if you are like me, the long term also - or at least until you can find/make some of the broken parts.

 

[matthewsx]

6. Find another lathe.

Not an attractive option but I will venture that you will find more things broken as you go along. You may be able to source all the parts needed and complete the repair but it's best to total up what you know is broken and make an honest assessment on the viability of a repair.

If you do go the repair route your best bet may be to source a similar machine for parts rather than trying to find them one at a time.

The dropped lathe I worked on wasn't a South Bend but you can find many tales of trying to fix a dropped lathe and most don't end well.

Good luck whatever you do.

John

 

[sdelivery]

Rick, I am already looking for parts for your lathe but there isn't much out there so far.
I believe you would be better off finding another machine.
Chance are the parts will come up in time....but my bet is you haven't seen all of the damage yet.
Can it be done? Anything can be done with enough money ,time and perseverance.


I thought 14 1/2 and 16 inch used the same parts?

 

[rwdenney]

Thanks—but it’s not as bad as all that. See my other thread for some testing I did on the rest of the lathe to make sure it was worth the repair. It’s not perfect but it should meet my hobbyist needs and it’s already in my shop.

I have been lucky today—I sourced a screw, a taper attachment bed bracket, and a binder stud, all for a 14-1/2, and all for a reasonable price. The screw is in good condition from the photos. I’ll need a cross-feed nut clamp screw, but that part is imminently makable.

That will be enough to get me going, I think. I’ll need to mess with the bushings in the screw to dial it in, but I was expecting to that anyway.

I’m still looking for the slide block—with that I can restore taper function, at least after I machine the connecting bar flat. That can go on the back burner. I have a routine need for machining a taper, but short enough to do it with the compound.

So, Number 2 it is for now.

Now, to the similarities with the 13 and 16. Here’s what I have learned:

A. The 14-1/2 screw uses the same 11/16-8 LH Acme thread as the 16, and the smooth part of the outer shaft is the same length and diameter as the 13. I suspect the threaded section is longer in the 16, and likewise the part that goes through the bed bracket.

B. The 14-1/2 taper attachment bed bracket is the same as used in the 13. The part number is PT862TF1. When the part number has TF in it, it’s used for both the 13 and the 14-1/2. When it has FH in it, it’s the same as in the 16. T=13”, F=14-1/2”, and H=16”. Likewise, the sleeve that goes through the bed bracket is the same for the 13 and 14-1/2.

C. The binder stud is the same as used on the 13.

D. The slide block is the same as with the 13. The taper block and plate are also the same (though mine are undamaged).

So, the taper attachment is mostly in common with the 13, but the screw uses the larger 11/16 thread in the cross slide as on the 16.

Yesterday, I had not quite learned the code in the parts manual, or I would not have suggested modifying a 16 taper attachment. It would be easy to use a 13 taper attachment, except for the screw, the connecting bar, and tie rod assembly (undamaged on mine).

Edit: Aaand, I just scored the slide block by searching for SB13 parts. I think I’ll be quite close to having restored the taper attachment.

Rick “feeling better” Denney

 

[sdelivery]

That is Great!
I am impressed with your learning the Southbend code, I was unaware of it.
Where did you find that information at?
Thanks Rick, I learned something.
Keep us informed of your progress

 

[brino]

That is Great!
I am impressed with your learning the Southbend code, I was unaware of it.
Where did you find that information at?
Thanks Rick, I learned something.
Keep us informed of your progress

Exactly the same feeling here!

Your "quick study" in SouthBend parts and manuals got you some deep understanding that many don't have.
Well done!

Brian

 

[matthewsx]

Good news, more pictures please.

 

[rwdenney]

That is Great!
I am impressed with your learning the Southbend code, I was unaware of it.
Where did you find that information at?
Thanks Rick, I learned something.
Keep us informed of your progress

From looking at the parts lists, it appears that SB part codes start with either "PT" or "AS", for "part" or "assembly". Not all parts were available separately and could only be bought as part of an assembly even though the parts list showed them separately.

The three digits that follow are the part or assembly number, which stays the same for that function no matter what the lathe size for lathes from the 10K to the 16/24.

Then, a letter or two that denotes which size lathe that part is for. R is for the 10K, T is for the 13, F is for the 14-1/2, and H is for the 16 and 16/24. These are the same letter codes that form the first position in the post-1947 serial number scheme.

Finally, there is what I believe is a version number for the part, usually 1 or 2.

So, for example, the "binder stud" (part 5 in the diagram in the OP) for the 16 is a PT867H1. All the binder studs are PT867's, but this one is only for the 16. But the 13 and 14-1/2 binder studs both show PT867TF1, and the "TF" denotes that the part is used for both the 13 and the 14-1/2. Sometimes, common parts will just show the "H" number in the 13 and 14-1/2 column, but these are usually for common parts like bolts and screws.

In the attached parts list for the taper attachment, I've circled some of the parts that are common to the 13 and 14-1/2, and a few that are common across other combinations. Parts that read "PTxxxFHy" are common to the 14-1/2 and 16, but the taper attachment parts are mostly common to the 13. One key exception is the tie-rod bracket, which this '95 parts manual showed as no longer available. That part was unique to the 14-1/2. Apparently, the one on my lathe was damaged in the past, because my tie-rod bracket is shop-built and machined from a block of steel instead of being a cast iron part.



The cross slide screw is shown on a different parts diagram (for the saddle) and is unique for the 14-1/2". But the brass nut that wraps around it is the same part number for the 14-1/2 and the 16 because they have the same threads. There were also different versions of that screw--a version for use with ball thrust bearings (mine uses bronze bushings, which I actually prefer) and a version that has hardened and ground threads (not needed for my hobbyist intentions).

On another note: I'm having trouble finding a replacement for the special screw that secures the brass cross slide screw nut. It has a small screw in the middle of it for oiling the cross slide screw threads. I've ordered some shim washers for shoulder bolts from McMaster, and with that I think I can reproduce that screw using a conventional 1/2" bolt. I also bought a shoulder bolt from McMaster that might make a better starting point. I'll drill and thread a hole through the middle of it to provide for oiling. This is the bolt that prevents the cross slide from moving with respect to the nut.

Other note: There are no thrust bearings in the front taper attachment screw (the part with the ball handle on it), as were shown with later screws that have the large direct-reading collars. So, the only way in which the rear taper attachment screw (the threaded part) is prevented from slop is with the thrust bushings that are part of the taper attachment. The front shaft's responsibility is only to turn the screw, either manually or using the power feed. So, converting this lathe to a non-taper version would require replacing the entire cross-slide screw assembly with the single screw used without the taper attachment, and including the retainer collar and everything else up by the handle.

As parts roll in, I will definitely make some photos and post them. But holiday responsibilities are likely to make that a slower process than I would like.

Rick "working on the machine is as fun as making stuff with it, as long as parts can be found" Denney

 

[rwdenney]

Exactly the same feeling here!

Your "quick study" in SouthBend parts and manuals got you some deep understanding that many don't have.
Well done!

Brian

Thanks--it's only possible because the work of so many others in preserving the old documentation for these tools.

Rick "researching documentation is half the fun" Denney