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Scraping my Boyar Shultz SG, need help! Table ways are hardened.

lowCountryCamo

Stainless
Joined
Jan 1, 2012
Location
Savannah, Georgia, USA
:ack2: I have been scraping my Surface grinder cause it would not grind flat. Parts came off the table convex .005 high in the center. As per Connelly I begain on the tower and head and they came along great. Very little wear. Moved to bed and carriage and that too was easy working. I thought, I'll be done in a couple weeks. I got to table ways wear I knew I had much wear. One v and one flat. V is low in the center .020" on rear side and low .015" on front side. The flat is a little better. The wear is obvious cause the oil grooves disappear in the center. So I spent a couple hours carefully setting up on the mill to take only the worst .010 or so out of the ends with a v cutting tool and I realized quickly that the ways are hardened. After closer look they are hardened steel wear strips about 1/16 thick epoxied in place. ERRRR!!!! What are my options?

Pics later this afternoon.
 
Be good to hear what Richard King will suggest on this.
I have grinder scraped a few hard things flat with using a large radius to the side of a 1 x 1 x ¼ ID stone with dressing a very large radius to the side and laying near flat for shallow scalloping.. the same with the end edge of an abrasive disk.. But I have not attempted to do something as large as a machine bed ways.
 
The worst part is I have so much material to remove. I might set up to mill some off with a carb end mill. Will wait to see what every one says. I don't know whether turcite is used on surface grinders. I believe all the wear came from grit embedding in the cast iron carriage and lapped the hardened table ways.
 
Hi,
To be honest I have never seen a grinder like this. How think are the hardended ways? I have seen Devlieg Jig Mills on the column ways that are ground and then epoxied on the cast iron surface on the rear side where the gib rides. A couple of pictures would help. I am thinking you can leave them on and have them ground in place or remove and replace them. Maybe some of the other guys have seen this and can offer some help. If not I will give my best guess opinion or call some other rebuilder friends and see if they have seen this before. Rich
 
:ack2: I have been scraping my Surface grinder cause it would not grind flat. Parts came off the table convex .005 high in the center. As per Connelly I begain on the tower and head and they came along great. Very little wear. Moved to bed and carriage and that too was easy working. I thought, I'll be done in a couple weeks. I got to table ways wear I knew I had much wear. One v and one flat. V is low in the center .020" on rear side and low .015" on front side. The flat is a little better. The wear is obvious cause the oil grooves disappear in the center. So I spent a couple hours carefully setting up on the mill to take only the worst .010 or so out of the ends with a v cutting tool and I realized quickly that the ways are hardened. After closer look they are hardened steel wear strips about 1/16 thick epoxied in place. ERRRR!!!! What are my options?
.

My Norton grinder has a similar setup, but with two V's and cylindrical rollers....and strips float, screw down at their ends. These strips on yours, they're plain bearings, ie no rollers? Interesting. Good news is when you figure out how to replace them there's no scraping to do! I always thought those on my Norton where a very intelligent design; hard durable and replaceable
 
I have see way rails that were bolted in place to a ground and boxed surface so replacing the rails would restore. but glued in that is new... even re gluing seems you would have to surface them. unless they are glued to a ground pocket? but how would they be .0005 or better that way?
 
That does not look like something a factory would do. The pockets someone has ground doesn't look professional. How is the table moved, via a rack and pinion and a hydraulic cylinder? does that look Rube Goldburg design? Rich
 
Richard it is rack driven. I just took a chisel and hammer and got under the corner and worked them right off. Now that I think about it they could have been an aftermarket addition. Maybe someone reground them and thought hardened steel against cast iron was smart. :nutter: However, now that they are off, the under side is a nice ground surface, cast iron. Maybe as saving grace, I set the table on the carriage and it fits just perfect. No interference accept I will have to mill .125 off the bottom of the rack as that is the thickness of the flat way strip. I probably still have some table sag so I will print and scrap if needed. I have been sweating this since last night but now I think it will work out. Here are some more pics. Thanks guys for your help. IMAG1085.jpgIMAG1087.jpgIMAG1088.jpgIMAG1088.jpgIMAG1089.jpg
 
The ground surface on the longer table would need to be scraped. I would first take a clean up rouch pass on the top of the table where the mag chuck sits as that surface is work hardened and if you don't do it prior to scraping the table ways it will move when you grind the able when your finished. Before I dismantle a grinder that I am going to scrape I grind the table top even if it is cock-eyed to relieve it.

I would set the table on 3 points and block it in before scraping. Having it on a table or a set of horses with-out setting it on 3 points will let the table twist. Measure 30% in from ends..this may vary with the way the table is designed as far as weight of the area's with the ways and the overhang. Have to make your best guess n the placement. I am assuming the bottom of the saddle is longer then the machine saddle base ways? If so scrape that first (on 3 points too) then match fit it to the top of the base saddle ways.

Then scrape the top of the saddle, first (I call this pre-qualifying) using a Camel-Back SE to be sure it isn't high in the middle before bluing up the saddle top with the newly scraped table. If you do not check the hinge / pivot / Airy points first you can not be sure those ways aren't high in the middle and are convex. The table will just roll over the convex and look like it is flat because you can not hinge the table on a V and Flat.

I say rebuilding a machine is like building a house, start at the footings by leveling and work up. I also think following the Connelly book verbatim can get you into trouble. It is all that is out there for the the basic's but many "pro's" don't use it.

As far as using Turcite or Moglice on the top of the saddle. They make the Turcite / Ruln .125" thick and you can pour Moglice that thick, so it could be done. Low country how much money do you want to spend? Are you going to need to buy a new rack a you said it looks bad?

I normally don't use PFE materals on grinders as grit embeds in it. But if Low C is not going to be using the grinder for production it will make the operation "slick". More later...got to get to the show. Rich
 
The ground surface on the longer table would need to be scraped. I would first take a clean up rouch pass on the top of the table where the mag chuck sits as that surface is work hardened and if you don't do it prior to scraping the table ways it will move when you grind the able when your finished. Before I dismantle a grinder that I am going to scrape I grind the table top even if it is cock-eyed to relieve it.

Never thought about that... good to know.
 
I think I will just scrap the cast iron table ways and not use any turcite if I don't have too. I am actually trying to save my pennies for a cnc mill so I want to spend the lease amount possible. I thank you all again for the help. Will post pics as I go.
 
I have successfully peened and straightened cast iron gibs using the method told by Richard King. I have also heard mention of peening a table to take some of the sag out. Would this process involve peening from the under side in several places. Richard, I have taken note to rough scrape the table top to stress relieve and will do that now. Thanks.
 
Pre-grinding/scraping table before scraping ways

Richard, I've seen you now, in several places, give the advice to remove the hardened material from the top of the table before scraping the ways. How much material should be removed?

You also say that you grind it even if it's cock-eyed. Was wondering about just using a hand-held angle grinder to buzz some off, since my table is slanted by 0.010" from back to front.

Many thanks.

ps. vague apology for reincarnating an old thread :)
 
More Tricks of the Trade

hmmmm...I guess I would consider grinding the table a Machinist job because that's the way I was trained. Over the years as a machinist* I have discovered quick ways to grind surface grinder table. A good grinder machinist has learned to speed up grinding a table top that is off .010" by plunge grinding straight down with tons of pumped coolant. At the end of each pass feed it down .0005 or more...have to experiment till you get it right and doesn't burn. This has to be done with coolant. Do Not try this with out coolant. So you use a coarse wheel dressed open and then instead of feed down .0002" and then feeding the table in and out. You do not use the cross feed, but you only feed down until you reach .009". Then raise it up and re-dress the wheel, calculate the amount removed feed the cross slide over the width of the wheel and plunge down and do it again and again until your all the way across the table. Then dress again and grind it the same old way.

As far as how much to grind off. I would say 2 or 3 thousands. If you scrape it with carbide 3 or 4 scrapes. You will feel the difference in the way it scrapes and grinds. The top is hard faced or some call it work hardened. I have never measured it, just did it. I have ground scored ways with a angle grinders to get them close, I have used air angle grinders to grind hardened ways, but have never ground a grinder table like that. Just seems crude to me. I suppose you could try it if your careful not to get it to hot or grind it to deep. I don't have problems re-generating old threads. There are tons and tons..or years and years of great info on practical machinist. Reincarnate as much as you want. Rich

* I am a Journeyman Machine Tool Rebuilder and part of being a rebuilder I had to learn to run machines. In my shop I had surface grinder's. I won't say I can program CNC's but I can hand sharpen a drill bit, sharpen lathe tool bits, run most types of conventional machines. I love running a single point planer or shaper. I have run VTL's. HBM,s, etc. One of my favorite machine was my Thomson Grinder. That is the type of machinist I am. I won't pretend to be a production machinist. But I know how to grind, mill, drill, turn, etc. . I love my trade! I love teaching my trade!
 
Lots of good , and bad info here. For sure whoever rebuilt this machine and put hard ways on it was from a different planet.

Most options have been discussed-

Turcite

Machine off way and start with new ones.

You could bolt Dura Bar inserts onto them, this should have been done in the beginning vs hardened strips.

This all depends on what you want to do and how much to spend. I would at least have the table ways machined, planed or ground so you have a master to work with to then scrape your saddle. This is normally what we will do as on larger machines not no easy to machine the base.
 
I used to work for Boyar Schultz as a machinist. Those hardened wear strips were indeed meant to be replaced when worn. They were 1/8" thick if I remember correctly. Although, from the factory perspective, we never had to worry about removal. Those oils grooves were done in my VMC, at least for the 3 years I worked there. Before that they were put in on Bridgeports.When I worked there, the factory was in a bit of turmoil and historically, still worked with extremely old technology and methods. Keep in mind, they closed in 1985 because they could not keep up with technology, overseas competition and union gridlock. And please don't chime in about the unions unless you saw the situation there first hand. But yes, those wear strips come with a chisel. Get it started and they will come off by themselves, almost.

Not to change the subject but there was an interesting mishap when an older gentleman had about 60 of those wear strips on a big Matteson grinder table and forgot to turn on the magnet. Well, most of them disappeared in an instant, taking out the guard on the left end of the table. Some went through the wall into the office area. Some went through a cinder block wall like swords and some went into steel work cabinets. Some were never found. Nobody was hurt, thank God. The operator, who was about 70 at the time was as white as a ghost and had to taken to the hospital. This happened as I ran a VMC right across the aisle from him.

Paul
 








 
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