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Is It Possible To Accurately Grind Lathe Ways At Home?

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Susan_in_SF

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Hi guys,
Quite awhile ago, I bought a South Bend 9A that was used extensively by the previous owner, until he passed away. I was told that he made a lot of guns with my new old lathe. When I bought it, I was a super newbie who didn't think about bed wear. I was blinded by the "South Bend" brand, and ignorant of basically everything.

After buying this lathe, I honestly did not plan on getting anymore lathes (lol). Then, a month later, on craigslist, I saw a just-posted ad from a guy eager to empty his storage unit that day since he was going on vacation the next day. I met him at the storage unit, and bought a South Bend 9C, along with a pair of steel workbench pedestal cabinets whose drawers were filled with supplies from the 1950's. I find it interesting how old timers used glass jars, coffee tins, and prescription bottles to store their screws, taps, etc. Anyways, I paid $120 for everything, and that's how I ended up with 2 South Bends (before I later got the free Logan lathe).

So, after a machinist friend suggested I keep the 2nd South Bend for spare parts, I decided to keep it instead of selling. I am glad I kept that 2nd lathe since I now know that my 9A lathe's ways are seriously worn. You can easily see the wear a few inches in front of the headstock. As for the older, 1930's 9c lathe, the ways are in really, really good condition. So, I plan on just swapping beds. I read online that I just need to drill an additional hole on the 9C bed to enable it to take the quick change box.

I am not sure what I am going to do with my worn bed after i swap it with the 9C bed.

Is it feasible to build a sliding table long to use on my little 612 surface grinder and 48 inch worn bed?

It just seems to be a shame to toss out this old bed. I read online that if the ways were ground, then the apron must be shimmed in order for the lathe to be accurate.
Despite my original plan on keeping the 2nd lathe for spare parts, I was thinking about selling the 2nd lathe, with the swapped 9A bed.

Is my idea of using my surface grinder on a 4ft bed crazy? If it is possible to McGyver a way to make it work, how?

Or should I just sell the 2nd lathe as is, with a worn bed (after I swap the beds)?

Thanks,
Susan
 

Bob Korves

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Possible? Yes.
Probable? Very highly not...

Susan, if the lathe is too worn, simply sell it and get a different one that serves your needs better. Some (very few) people enjoy scraping in an entire machine for their hobby shop. Others enjoy other means of self flagellation. Be ready for the very high learning curve and immense amount of work, time, and patience it will take to do the job properly. I would guess that 99 of 100 machines that are torn apart by amateurs for restoring to functionally new condition (not just made pretty again) are eventually put back together unfinished or sold as basket cases or as replacement parts. Keep in mind that hobbyists do things for enjoyment.
 

bhigdog

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Three ways to approach this.
1. Junk or sell the bed.
2. Try scraping the bed as a learning experience before junking it.
3. Use it as is as a learning experience. I've seen some of the nicest work done on the most clapped out machines because the operator knew it well and worked with it's flaws rather than against them...............Bob
 

Cadillac STS

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Would it be possible to flip the bed around so the headstock is now at the less used tailstock end?
 

benmychree

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ON A LATHE WITH FLAT WAYS, THAT MIGHT BE THEORETICALLY POSSIBLE, BUT THE south BEND LATHES ARE NOT MADE THAT WAY, THE A VEE AND FLAT WAY FOR BOTH THE CARRIAGE AND HEAD AND TAILSTOCKS, THEY WOULD BE REVERSED AND NO WAY TO GUIDE AND ALIGN THE RESPECTIVE ELEMENTS.
 

Superburban

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Agreed. The South bend has a Vee, and a flat on the front side, and 2 vees on the rear.lathebed004.jpg
 

P. Waller

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Any simple engineering problem may be overcome with the simple application of economic lubricant.
Sufficient lubricant will create a new and better performing machine every time.

If one has the income for such a project there is no reason that way grinding CAN NOT BE DONE in a home shop.
You merely need a large home shop and a good deal of money. I suspect that the original SB way grinders for small lathes would fit in the average five car garages supplied with modern upscale homes if the Mercedes, BMW's and Porsche's were removed (-:
 

Superburban

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Depending on how good, good enough is, I'm sure many here could do it. The key, I think is identifying where to key off of? The saddle vees will be more worn at the head end, and the tail stock ways will be more worn at the other end.

If the tail stock ways are not worn much, that could be a good contender for using to guide off of. But you will need to know the working ways will be off towards the tail end.

I'm thinking that a little self powered laser with flat sides, could be used to measure how off things are. With the laser in the chuck, and spinning, one could slide the tail stock, and watch where the laser dot (hopefully not a circle), hits on the tailstock. Then you could mount something to the cross slide, then move the saddle from one end to the other.

Now, could one design a sled that uses the base of the tail stock, but has everything adjustable, so the operator could adjust it as you slide it from one end to the other, to keep the laser dot on a target. I think so.

I think if one designed such sled, and a similar sled that guides off the saddle ways to grind the tail stock ways. Theoretically, if one used the two sleds, and alternated after each is ground close, the accuracy should get better each time.

Then you need to look at the saddle. How do you fix the vees? and make sure they are perpendicular to the cross slide ways? And the proper distance apart?

Could one use brass stripes to build up the saddle ways/Vees? I know there is a fed different plastic based methods that will work, but the ones I looked up, are expensive for a guy on a fixed income, and will not likely use the lathe more then once a month or so.
 

derf

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You guys don't have much imagination.......
Keep it, and make it into a wood lathe, with a copy feature.
Keep it, and make a polishing lathe by adding a belt sander.
Keep it, and make it a rotary welding rig with a mig welder.
Keep it, and make a large drum sander/disc sander.
Lots more possibilities...it's NOT worthless.
 

Richard King 2

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If you have a lot of time and money to play with it, give it a try and flip the bed, would be a great learning curve and a laughable thread to watch and read. get it back together, What about the feed rack, is the tail stock ways flipable? Will TS set on the V and flat or will you have to make a new tails stock base? will the centerline of the feed shaft line up? Have you measured the worn area? Most people just see a small error and file the shaft if its a bit bigger. There is a You Tube show of some dude using the tail stock ways and TS base with a grinder attached and he grinds the bed.

I wonder how many times he tried to do it? You Tube can be faked. How do you plan on using the lathe? Chucking the part and not using the TS? Or Center to center? So many questions need answering. Then call around to some CA grinding shops and get a quote to have the bed ground. https://www.thomasnet.com/profile/00453314/american-grinding-machine-co.html?cid=453314&cov=CS&heading=36191807&searchpos=1&what=Surface+Grinding

There is one of these companies who I can't recall at the moment as I am in MN. They ground a friend of mines bed for $250.00 just a couple of years ago, It was a SAG lathe and it was approx. 60" long. BenChee you probably know who it is>? So you can screw around and F ed up a perfectly good lathe bed going 1/2 cocked or just grind or plane the bed
 

just old al

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I just went through this exact sequence. My SB 9 had a bed that had been 'scraped' by the previous owner...badly. I am not seeing that as a viable method of repair in the home shop unless you do it as a labour of love.

Just replaced the bed and it transformed the machine. Bed I used came from a commercial shop where all the tooling had been designed to lock down to the bed and it moved - so the ways were pristine. Best hundred bucks I ever spent...

Sell off the worn-out A model and learn to love changewheels - I've owned both an A and a C and had no problem cutting threads with either.

If you do want to move over the gearbox from one to the other and part out the old one, do take the time to examine the condition of the gearing, leadscrew and the apron (which will need to all go along). If they're worn it's likely more trouble than it's worth to make the changes once you add in refurbishing the power train.

I've done these things and ended up with a great lathe - but it's a lot of work and condition of the parts is a major factor.

Alan
 

machPete99

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If the bed is overly long you might be able to cut off a chunk at the headstock end, which is where most of the wear will be.
 

Bob Korves

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Great timing here. Check this out.
That could perhaps do to rough it in, still not close enough, and way too dangerous for words. Sad way to treat a surface plate, too. It would still need to be scraped in to be within factory tolerances. Clever idea, though...
 

rgray

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That could perhaps do to rough it in,
Plus they had flat ways. V-ways would add plenty of complication.
And then most don't have a scrap 4 or 5 foot surface plate laying around either.
 

BtoVin83

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Been thinking about this and I think a person could make a slide way using Thompson linear ball bearings and hard chromed rod. You would have to make it sturdy either bolting it down to some thing substantial or to the bed itself. Build a carriage assembly using 4 of the linear bearings. Plus you would need to have someway of dialing it in parallel to the ways. Also you would need to mount the grinder at angles for the v ways. It may not be fantastical but you could probably improve the accuracy.
 

john.k

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There are plenty of lathe buyers who dont even know what bed wear is,or even care ,in some cases.If you sell at a newby price,a worn bed wont affect anything............in answer to the question.......can it be done? ..yes.................is it advisable? ....no.
 

mmcmdl

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I have to bring the SB heavy 10 home this weekend . The bed is toast , the rest not so bad . I'm following along all the bed grinding threads trying to determine to get it done or just live with it . I have no need to hold .0001 on anything . I'm thinking of a pretty it up and paint it job and let it be , or make it a donor and try and get ahold of that 9" Jet .
 

chips&more

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I’m sorry to say, but if you offered the 9A and or 9C to me for free, I would not take them. I have been around the block. Been there and done that kinda thing. I no longer want any frustrations that go along with lathes that have idiosyncrasies. If I had limited space and short on time. I would get the best newer working lathe with bells and whistles and be done with it. Use it and enjoy it. And not play around with repairing anything about it to maybe make it work. I have 10 generations of hobby shop projects and only one lifetime to do it in. Maybe some folks have it in their cards to do this sort of lathe entertainment, I do not. Sorry, my three cents…Dave.
 

john.k

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On the subject of worn beds..............I worked for a multinational co that had the most abysimally worn machines I have ever seen.......some had 1/4" wear in the beds...........and multispindle autos that were scrap metal................Crane Copper was the name.....the factory had massive output,but went out of business because of the development of chromed diecast mazak bathroom fittings............absolute rubbish,but new house builders loved the non copper prices.
 
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Richard King 2

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All these amateur devises have been thought of already, lathes have been worn for years and years. Nothing new. Go for it and wreck your lathe bed. Be sure to take a lot of photo's a You Tube shows. . We all need a good laugh.
 

hman

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Susan -
I don't know diddly anything about surface grinding ... but you can get a taste of what's involved in scraping a lathe in the January/February issue of The Home Shop Machinist. The lead article describes scraping the saddle, cross slide, etc. of a 9x20. Unfortunately, the author did not include the bed ways. But you can at least get a sense of what's involved.
 

Richard King 2

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Or search You Tube and "Richard King Scraping" and see a dozen shows from my students. I also sell the Edward Connelly book "Machine Tool Reconditioning and my DVD that teaches all sort of rebuilding and scraping. Can see them advertised on Ebay under BIAX
 

Cadillac STS

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On the subject of worn beds..............I worked for a multinational co that had the most abysimally worn machines I have ever seen.......some had 1/4" wear in the beds...........and multispindle autos that were scrap metal................Crane Copper was the name.....the factory had massive output,but went out of business because of the development of chromed diecast mazak bathroom fittings............absolute rubbish,but new house builders loved the non copper prices.
With the well worn machines were they still able to produce quality commercial parts? Just wondering because it could go to show with compensating for the wear on the machine it is still able to make a good part. Comes down to the operator. For example one person may fret about wear on the lathe bed and not even try to use it, the next person just uses it and gets the quality part they want out of it.

Also, worth mentioning having a worn lathe to work with is better than having no lathe to work with...
 

martik777

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I had .010-.015 wear mostly on the front 6" V way on one of my 9A's. What I did for a few years was to move the headstock down about 10". All you need is an extension for the stud gear and some guards. Then I finally decided to plane the front way with a taig compound attached to the tailstock using a carbide toolbit. Took about an an hour with some fine adjustments with a scraper. Now I can cut within .001 for several inches.
 

chips&more

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If the lathe has any of the below, I don’t want it…



It has change gears that are stored in a draw

It uses a belt just like you wear around your waist

The chuck will smash your toes if the lathe is run in reverse

It turns a taper, but the lathe does not have a taper attachment

The spindle turns so slow, you think you’re looking at a second hand

You wonder why the longitudinal feed handle is way over on the right end of the bed

You can’t find any carriage power feed, maybe longitudinal, but that’s not good enough

The bed is made out of aluminum or something other than a good grade of cast iron.

The jib shims/wedges are plastic
 
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