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To scrape or not to scrape .. that is MY question

MyLilMule

Hot Rolled
Joined
Jan 5, 2021
Location
Ohio, USA
I am new to this. Please be gentle. LOL.

I have acquired my first piece of metal working machinery, a 1941 13" South Bend Lathe. The ways have noticeable wear. I found a small machine shop local to me that can grind the ways, along with the saddle to match, for a "reasonable" price ($700).

However, they can't do anything with the dovetails in the cross slide or the compound - they don't have the equipment for it. They also do NOT have the ability to scrape any of it, I would have to take it somewhere else.

That being said, the real question I still have to answer: is grinding it even worth it if I am not going to have them scraped? Since I have never done scraping before, nor would I know where to start (besides YooToob), or know anyone that owes me a favor, I would have to hire someone to do that for me. And, being an art that scraping appears to be, will likely be rather costly.

So I could potentially put more into grinding and scraping the ways than the lathe is even worth. I have no emotional attachment to it, outside of the fact that it's almost as old as my Dad.

The lathe is currently being dismantled for cleaning and refurbishment. I am already replacing the half nuts and the twin gears (they were total junk). So to take the ways and saddle to a machine shop wouldn't be a big deal.

I figure I have these options:

1. Leave them alone, clean it, put it back together, and have fun making parts
2. Quit whining about $700 (I'm not, really) and have the ways ground because it will improve your ability to make parts (or will it?)
3. Sell a kidney and have them ground and scraped. (There's an awesome place in WI that will do everything for $4200, six times what I paid for the lathe, if I ship them halfway across the country). And have fun making parts, if I can afford some raw stock.

I know what I DON'T want to do, and that is spend multiples of what the lathe is worth, even after all is said and done. I could put that kind of scratch into a more "modern" or less abused lathe. Spending the money to have them ground is well within what I am comfortable with, but only if I don't do more harm than good.

Pic for reference:

IMG_2889.jpg

So, WWYD? TIA.
 
Contact Cash Masters in Milwaukee - knifemaker.com as he can grind the bed and dove tails. Or buy a dove tail cutter and mill them.. I have been talking to a former student about doing a class in Ohio next summer.

I would grind or plane the bed.
 
a small machine shop local to me that can grind the ways, along with the saddle to match, for a "reasonable" price ($700).
Ways AND "saddle to match" that is a good price.

Not said if that includes "raising" the carriage back up with one of the miracle plastics so the leadscrew alignment is restored. "Not likely!", so that's more money spent. Maybe $200 for the materials? And it MUST be done - but you can learn to do that yourself.

I am puzzled though. Very.

If they can grind the bed AND grind the underside of the saddle, then they DO have what it takes to also grind the cross and the compound. Or "at least" mill them so there is not a lot of scraping left to finalize.

Even so, you just used a keyboard? You CAN learn scraping, too.

If you cannot take one of Richard's courses, you can probably learn enough from his videos plus a lot of reading, "Right here, on PM". And practice.

Youtube has "some" good information. And a lot more NOT so good. Best to go through Rich's CD/DVD FIRST. It will help you avoid the bad roads.

So, WWYD? TIA

"None of the above".

I'd trade a(ny) SB away. Then buy a lathe that could make better parts with whatever wear it had left TF alone.

From that better starting point, it is no longer as urgent that it gets a full rebuild - or gets partial ones done as "projects", spread out over time. Or never gets them at all.

It comes down to what your direction is and how long you have to chase your goal. Or might give-it-up and take chase after some OTHER avocation. My one was flying airplanes. Making good night landings. Not making chips.

Then again? MY (late) Dad was born in 1910. So I don't have as much time left to get the use out of a nicely rebuilt machine tool as you should have.

But I do know how to get "acceptable" work out of far, far, worse ones than I actually have.

Bottom line(s)?

- Save yer cash AND your time.

- "Run what you got!" for a year or so.

- LEARN.. to compensate for its faults.

- Take a separate decision as to how much you want to learn about scraping.

- THEN.. in a year or three... you will be in a better position to find yourself a better lathe.

In better condition or not, one WORTH investing in.

Not talking about a Monarch or a Hendey Tool & Gage. See DocsMachine thread on "Saving a Springfield".

A(ny) SB is only "training wheels". There are MANY medium to heavy built lathes "out there" that will BE something if restored. A SB will still be but a very light lathe for hobby work, even if it were brand-new.

With a bit more experience, you will be better able to evaluate the NEXT purchase and say:

- "I can scrape that myself.."

Or:

- "I can NOW afford to hire that part done, and it is worth it."

Meanwhile? It is only a spaghetti-bed South Bend. Born with Iron deficiency Anemia.

Don't let it become a hole in the shop space into which you shovel money.

:D
 
From a value point, South Bends have a certain following due to nostalgia, cost, parts availability, and weight. The weight/size allows more guys to drags one home. An operational 13" I'd expect to fall into $1500-$3000 resell range. Generally $3k if its pretty decent. Might push over that with ground and scraped ways, but the audience/buyers are getting less.

A South Bend 13" probably weighs 2000lbs. A Monarch 10EE with a 12.5" swing 4000lbs maybe ? A 13" Monarch series 61 probably in the vicinity of 7000lbs plus.

But part of the calculation is not just resale. Its how long to you intend to use the machine. If you keep it 1 year, then I'm not sure I'd want to be $4k plus into it. If you keep it 10 years, could well be worth it, as it will earn its money back in higher accurate work, or less time needed compensating for inaccuracies, work arounds etc.

Thermite mentioned Turcite or the like for raising saddle back up, for lead screw alignment, a real possibility. But with South Bends, rather than raise saddle, you can also lower qcgb, rack(underside of bed for driving apron), and lead screw end bearing. You do that by shimming those 3 pieces down. All to get the alignment of leadscrew through apron correct, and apron pinion gear to reach rack. Cost for shimming down would be not much, shim stock and time.

Another note, with grinding alone your saddle may no longer slide on ways. Right now if you shoot some oil on ways, lay saddle on there, you could push saddle back and forth with your hands. After a re-grind that may not happen till you get scraped in. That's not flaking, that's just scraped in to fit right.
 
I’d try sending it down the road as is first or part it out and scrap it to break even. Not that anyone here has implied anything but no matter what some guys say...it’s impossible to save them all. It will be months and thousands of dollars in repairs when a newer and tighter machine could be picked up and making parts by the end of the week.

Myself, I have no problem with repairs but I’m past the major projects. Spend $1.5-3k on a clean usable machine from the beginning and you won’t regret it. HGR probably has something nicer sitting on the floor.
 
Sometimes that's the best thing to do....Another thing you could do is use it as-is until you can afford something better. Another note: In my career of over 50 years I have never seen anyone shim down the rack and move the the feed screws on each end. I know several machine tool rebuilders who don't screw something up to repair a worn saddle. Turcite /Rulon is cheap and scrapes like butter.

I had a guy call me yesterday and he is going to put new turcite on the saddle of his box way VMC. I told him how to do it over the phone plus told him to watch Keith Rucker's YouTube show, where Lance Balzley scrapes Turcite.
 
Another note: In my career of over 50 years I have never seen anyone shim down the rack and move the the feed screws on each end. I know several machine tool rebuilders who don't screw something up to repair a worn saddle.

Not my invention, but I have read it several places with South Bends. Can't do it on all lathes, for many the mounting on any or all 3 key pieces may be different. But on larger South Bends the rack, qcgb, and lead screw end bearing all mount on bottom side of bed way, and can be shimmed straight down without a lot of hassle. At least on the larger South Bends that I'm aware of.

An example is thomas utley's South Bend 16". A fellow member ground 22 surfaces on the lathe. The only turcite they used was on one gib. If you read a few posts down from this link there are some details:
1943 South Bend 16" x 60" Lathe Resurrection

Later in the build he says the shimming is on the to do list:
1943 South Bend 16" x 60" Lathe Resurrection

In part I think this is possible because of the banjo holding 3 gear assemblies, for the gears that drive apron off head stock. That banjo is adjustable with a large slot. If you follow the black painted banjo in this pic, up from qcgb, toward rear of lathe, you can make out the large adjustment slot. You can adjust to get gear lash correct for that whole assembly, even with shimming qcgb down:

489.jpg
 
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Thanks all for the great advice.

I think what I am going to do is use it as is. I am still going to disassemble everything for cleaning, painting and lubrication. I'll take my time reassembling everything, checking things as I go. If I find it is too far out of whack once it's operational, I can decide then just how far I want to go. Keep it as a backup and get something else, or sell it to someone who doesn't care as much. I might not care as much. :) But taking it apart again will be no big deal should I decide to dial it in. Honestly, my gut tells me it's going to be fine as is.

I have watched several of the various YooToobers scraping ways, but never paid that close attention. After recently watching a few of Keith's videos restoring his Monarch, even when he ran into a problem with the gib, I think scraping is something I can learn how to do and would like to learn how to do. Perhaps when Richard offers a class here in Ohio, I'll be in a position to be able to attend.

Thanks again for all your input.
 
One of the last FL class students was from Ohio and said wanted to host a class in 2021 after he got his shop organized. I know the feeling as my shop need a lot of work as I have been storing "stuff" for years and it's amess....lol. I always have an invitation to do another class at John Saunders or NYC CNC another youtuber and is in central Ohio.
 
I vote that you clean it up and re-assemble and use as-is, if you need a better lathe just buy it. On a machine that is worth re-building sure, on an old SB its a fools folly imho. Did you buy a lathe to learn to make parts, or to learn how to scrape?
 
what the lady said...

Takes a huge amount of time to merely reassemble and paint a machine, let alone scrape into alignment. I totally understand the desire to get to know a machine intimately and to be infatuated by it - the newness, the promise of future cool projects, the fascination with how it works, the learning of cool new stuff, etc, etc. I still feel that every time a machine rolls through the door. But... having done all of the above a couple times, and some CNC conversions, I take a harder look at the time required.

Don't misunderstand me, it's fine if you do it!

Estimate the time you think it'll take and multiply by 10. :D If you think it's still worth it, go for it.
 
Resurrected my old thread.

The lathe is officially back together and operational. Everything is running great. My only complaints are that is some of the spindle speed/gear positions, the primary gear train makes a ton of noise. I thought I knew where it was coming from, and replaced a couple gears, but turns out I didn't dig enough to find the actual source. However, I'm not changing that - it's just noise. The other complaint is the bed wear. Although it isn't bad for what I am doing, I do wish it was in better shape. I recently bought a mill that needs some repairs, but I may get adventurous, once it is back together, to use it to dress the dove tails on the cross slide and compound, IF I decide to have the bed and saddle ground true.

So my newest question, for those with real experience, is this, what can I get away with on tools for scraping in the bed, since I am starting with nothing? With a 5' bed, does that mean I need a (minimum) 5' straight edge? Recalling that this is in my home hobby shop and I do not have access to a full machine shop, and I would like to learn and do this myself, what are my options? My 18" x 12" B grade Starrett plate isn't going to work, and I don't have the room for anything bigger. The plan would be to try and take one of the Kind scraping classes and learn how to manually scrape (no Biax machine) and then work my way to the tools I need and go from there.

Sending it out is not an option. I like the lathe, but not that much that I am going to invest 3 times what it is worth - I'd rather sell it and get something else. BUT, I can have it ground for not that much, and my labor is free, I just need to know what I would be in for as far as tools.
 
Contact Cash Masters in Milwaukee - knifemaker.com as he can grind the bed and dove tails. Or buy a dove tail cutter and mill them.. I have been talking to a former student about doing a class in Ohio next summer.

I would grind or plane the bed.

If this happens I’m in! I’m in Cincinnati. Richard take my money already!!
 
Mylilmule you don’t have to scrape the ways at all, my sb16 has hardened and ground ways from factory and they were never scraped. Your beds not hard so it’ll wear quicker then mine but your a hobby guy right? Well the light work load in a hobby shop will extend its life 10 fold easy.

Remember some of these lathes pulled in 40 hour work weeks before many of us were alive, just grind the bed and use it!

Afterwards some day throw the dovetails on a mill and true them up too.

If you grind the bed alone I think you’ll rid yourself of 80% of all error In your lathe off rip.
 
Resurrected my old thread.

.............. The other complaint is the bed wear. Although it isn't bad for what I am doing, I do wish it was in better shape. I recently bought a mill that needs some repairs, but I may get adventurous, once it is back together, to use it to dress the dove tails on the cross slide and compound, IF I decide to have the bed and saddle ground true.
.................

1) Scraping SB ways add another level over most, due to double V ways. Not the machine I would suggest learning on..... Grinding is OK, IF you can get the carriage done to match as well.

2) and more importantly, "wear" is not a thing.... "X amount of wear in this location" IS a thing.....

The effect of wear really depends on how much. And where it is. And what you expect to be doing.

Wear normally drops the tool below center in some places along the bed, typically near the headstock.

So, what is the effect? In many cases, not much.

Do some trigonometry, and figure out what effect on the diameter of a 1" part will result from the tool being lower by 0.020". It will not be much. Almost a thou on the diameter. And that is a LOT of wear.

So if you were turning a part that is as long as your lathe will accept, that error would occur as you move from much less worn areas, to the worn area.

But, if you are turning a 1" diameter part that long, and you want accuracy, you should be using a follow rest. That should reduce the error if adjusted decently, although expecting any older SB machine to get into tenths is a big ask, especially with a long part.

And, if you need tenths on a shaft that long, you almost certainly need to be grinding it anyway, since just the surface finish will need to be better than typical turning on that type of lathe.

If you have to have that accuracy, and must use the lathe, then you will want to finish the job my measuring at different points along the part, and polishing to size. That will let you get as good as your mics, and your technique, will allow.

Bottom line is that Even 20 thou is not a huge deal. With small diameters, it can be more significant, but with smaller parts, your parts are also not as long. Generally they will be short enough to be entirely within the worn area of the bed, and the wear basically disappears as an issue.

Wear really only has an effect if the carriage has to move from less worn to more worn areas, or the reverse. If the wear is essentially even in the area being used, it has no effect.

And as long as you own decent mics, you can make parts to size on a worn lathe even if the "cross the wear boundary".

Just USE that puppy.
 
1) Scraping SB ways add another level over most, due to double V ways. Not the machine I would suggest learning on..... Grinding is OK, IF you can get the carriage done to match as well.

2) and more importantly, "wear" is not a thing.... "X amount of wear in this location" IS a thing.....

The effect of wear really depends on how much. And where it is. And what you expect to be doing.

Wear normally drops the tool below center in some places along the bed, typically near the headstock.

So, what is the effect? In many cases, not much.

Do some trigonometry, and figure out what effect on the diameter of a 1" part will result from the tool being lower by 0.020". It will not be much. Almost a thou on the diameter. And that is a LOT of wear.

So if you were turning a part that is as long as your lathe will accept, that error would occur as you move from much less worn areas, to the worn area.

But, if you are turning a 1" diameter part that long, and you want accuracy, you should be using a follow rest. That should reduce the error if adjusted decently, although expecting any older SB machine to get into tenths is a big ask, especially with a long part.

And, if you need tenths on a shaft that long, you almost certainly need to be grinding it anyway, since just the surface finish will need to be better than typical turning on that type of lathe.

If you have to have that accuracy, and must use the lathe, then you will want to finish the job my measuring at different points along the part, and polishing to size. That will let you get as good as your mics, and your technique, will allow.

Bottom line is that Even 20 thou is not a huge deal. With small diameters, it can be more significant, but with smaller parts, your parts are also not as long. Generally they will be short enough to be entirely within the worn area of the bed, and the wear basically disappears as an issue.

Wear really only has an effect if the carriage has to move from less worn to more worn areas, or the reverse. If the wear is essentially even in the area being used, it has no effect.

And as long as you own decent mics, you can make parts to size on a worn lathe even if the "cross the wear boundary".

Just USE that puppy.

Did you account for the unequal wear in the front v way VS the rear on a southbend? On SB lathes the saddle is considerably heavier on the operator side then the other amd as such wears into the operator side v way SIGNIFICANTLY more then the other. The tool post does more then just “dip” it actually leans away from the work towards the operator in addition to dipping below center and the taller the tool post the worse this gets, so I think your numbers may be off but idk, I agree use it as is, it’s a SB not a 10EE
 
Did you account for the unequal wear in the front v way VS the rear on a southbend? On SB lathes the saddle is considerably heavier on the operator side then the other amd as such wears into the operator side v way SIGNIFICANTLY more then the other. The tool post does more then just “dip” it actually leans away from the work towards the operator in addition to dipping below center and the taller the tool post the worse this gets, so I think your numbers may be off but idk, I agree use it as is, it’s a SB not a 10EE

I know of that issue. But in most cases that seems not too big a deal, it's the difference in wear that does the tilt. The movement also depends on the "vertical lever arm", which is not as large as the distance between the "V" ways, IIRC. Could have forgotten since the last time I owned an SB.
 
I know of that issue. But in most cases that seems not too big a deal, it's the difference in wear that does the tilt. The movement also depends on the "vertical lever arm", which is not as large as the distance between the "V" ways, IIRC. Could have forgotten since the last time I owned an SB.

Your correct in my case, my SB16 is roughly 10-1/2” tip to tip on the saddle v ways and 7-5/8” from v to axis centerline. I’m curious about the math, I’m not good at the numbers and would want to know what kind of movement were actually getting on a worn Sb vway. My front way has AT LEAST 4x the wear my rear does. It’s visually noticeable, I measured it below .001 but I don’t have any higher resolution/Technique on hand.
What’s .001 drop on the front v way equal at the tool tip?
 








 
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