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GDS12

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I was just starting to look at surface grinders and was wondering what the consensus is on which is best when buying older, used machines. I have my eye on a couple Boyar Schultz 6x12's but I also see a couple Brown and Sharpes and Harig Super 612's etc... All are on local (or fairly local) Craigslist ads. Seem to be in the $500 to $1500 range. Are there any machines to stay away from used? Any advice and suggestions are welcome.
Thanks
Gary
 

Bob Korves

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Any of those three brands were very good machines when new. However, many or most of the used surface grinders being sold (at least around here) have major issues. The biggest one is the spindle. It must be in very good to excellent condition or you will not get good results. Repairing or rebuilding a surface grinder spindle is not really a job for a hobby machinist. It needs to be done correctly, and we don't really have the skills and experience and special equipment to do that job right. Also, some spindle bearings for surface grinders are obsolete, which leaves you in a bind. They are also quite expensive to prohibitively expensive, and you will probably have to take it apart to find out which bearings it takes. Again, you would also need the skills and equipment to rebuild a precision spindle. Learn how to check a spindle before looking at surface grinders, or take someone who is an expert at it with you to look at candidates. Buying a properly rebuilt spindle or having one rebuilt professionally will cost a LOT of money.

The ways of the machines are also often well worn. After all, they live in a gritty environment. You must take the table off and inspect the ways and/or rollers or balls that the table traverses on. The saddle ways can also be worn out, and, less often the vertical ways for the up and down axis. Missing or damaged covers and shields that keep the grit out are reason for walking away directly, and so is grit or signs of lack of lubrication under the covers and in the ways. They don't have to be perfect, but they need to be good for good results, and good surface grinders are not what you usually find for sale. I know I am being heavy about this, but don't want to see you or anyone getting stuck with something that looks like a surface grinder, but is actually essentially scrap metal.

Get a decent one and you will really enjoy what you can do with it!
 
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Dabbler

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+1 to everything Bob as just said. Nowadays people are unloading manual/hydralic grinders inf favour of CNC surface grinders. That is great for us, where often fine machines are being dumped. And the 'average hobbyist isn't interested. Makes for great deals for us!

Most grinders have ways that can be inspected from below: look for scored/scarred ways or dry ways. those are going to give you more trouble than wet shiny (or scraped) ways. If the grinder is really cheap, say under $700, and the spindle is quiet without having a periodic 'whine' then it will give you good service, even if it isn't a $2000 machine.

If you want a 20 micron machine, be prepared to pay a fair price, in the 2K$ range - great deals are out there, but that would be rare.
 

Cooter Brown

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I have a Boyar Schultz 6x12 its a great machine.... If you go look at one lift the table off and check the ways for wear, turn the spindle by hand to check the spindle bearings and to see if the spindle is bent.... Also try not to buy one that you can't see powered up, the motors are unusual and will need to be rebuilt and that's not exactly cheap..... I paid $550 for mine a few years ago....
 

Grandpop

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Agree that spindle should be relatively quiet and no obvious vibration when you touch it behind the wheel guard.

The Boyar Schultz certainly is a well made machine (I own one), and was copied by lots of importers, so lots of clones out there. Not much in way of parts available, but typically don't need many as can get/make most of them. Harig, Chevalier, Brown and Sharp, Doall and others are very similarly well made units. Best I ever ran were the Mitsui / Okamota ball way machines, hands down.

Most them will have worn ways and screws in middle of travel, anywhere from light to heavy wear. Best to get an idea of how much it has before you take it home, and compare that to what you want the machine to do.

Not sure what the market is like near you, but around here the Boyars go for same as you, others maybe 1000-2500, and Mitsui / Okamota maybe 3500-5000. Much as I wanted a Mitsui, I could not justify the cost.

I paid 500 for mine, spindle reasonably quiet, rubber dust guards split, .020 backlash, and extremely dirty, but 15 miles from home with free loading onto my trailer. I have another 500 into it for all new oil metering valves (old grinders valves are typically clogged), new rubber guards, new bellows for the cross screw, missing wheel guard, etc. Also added now oil marks to table, cleaned out the lube tank, and cleaned it all up (lot of work). I have done a fair amount of work with it, and seems reasonably accurate, can usually get within .0002, good enough for home use.

No matter what you buy, will most likely need 200-500 to get it into good running shape. All just depends on what you want it to do.
 

Bob Korves

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Don't buy a machine that you cannot see running before purchase unless you really like rolling the dice. Also test the mag chuck and grind a smaller piece or two of hardened tool steel to see what kind of results it gives. Another reason to bring a knowledgeable grinder hand along with you if possible.

Edit: turn the spindle, carefully feeling for ANY roughness or play in the bearings, BEFORE you run the machine. None is acceptable.
 
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Bob Korves

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Are there any machines to stay away from used?
The lower end Chinese machines are often put together with ordinary bearings, and use other cost cutting downgrades to meet a price point. It is often difficult to get a good finish with those machines even when they are new. Some of the better Asian machines are just fine if in good shape.
 

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Stick to the 'name' brands, as these industrial machines are nearly bulletproof. As long as they don't have bad ways and decent spindle, these will serve you well.

Another one to stay away from is Ingar, a spanish machine. If it is really new, it can be good, but they don't seem to last long, so you are far more likely to get a worn out one. I know someone with a rare great one. I almost bought one, long distance, but I'm very happy with my Brown and Sharpe.
 

Ulma Doctor

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all the brand names you listed are quality machines.

i was lucky to find a single owner one man shop who sold his Boyar-Schultz 618 to me for 1K
 

Dabbler

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you're right. If you live near them, they have a lot of stock!
 

Cadillac STS

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Something I noticed just recently about surface grinders and Craigslist. They don't show up much under tools. But search "Surface Grinder" for the whole Craigslist site and they do show up plenty. They are listed as heavy equipment or business for sale maybe other headings.
 

GDS12

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I wound up just buying a Harig Super 612 at an auction last week. A couple of Harig's were available among numerous newer high priced Japanese machines. I managed to speak to the owner of the tool shop who contracted with the auction shop and got the inside scoop on the machine's history. He indicated that it had seen little use in the most recent years and was never used in a "production" environment. At some point several years back it was completely rebuilt by S.T.K. with new bearings and converted to ball races. Not sure what the conversion to ball races means but the spindle/motor is dead silent and all seems to function very smoothly. He said it was a great machine and didn't have any issues so I was pleased with that. I had to hire some licensed/bonded movers to move it to my shop and they are scheduled to move it early next week. My question is how do I prep it for moving? Do I need to remove the table? Does the table just sit on top? If you don't have to disassemble that, is it good to just use wood blocks between the spindle and the table/chuck and let the spindle just rest down on the chuck surface? I am concerned that I need to somehow disassemble a bunch of stuff before they move it...

Thoughts?

Gary
 

Bob Korves

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You must remove the table or the balls can hammer little divots into the ways while in transit, totally ruining the machine. The table should lift right off, but there may be a cable or other means of traversing the table that needs to be disconnected before it lifts off. Put some blocks under the spindle housing, then let down the head until there is no load on the lead screw, with backlash in both directions. That way there will not be pounding on the precision lead screw threads. It sounds like you may have a very nice grinder there. Without pics posted here, it never happened! Congratulations!
 

GDS12

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I'll try to get some pictures up soon. Are the balls just loose? So all I do is lift it off after disconnecting the cable?
 

Bob Korves

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I assume the balls will be trapped in holes in spacer plates thinner than the ball diameter. They may well be loose, though, and if so can roll all over the place if you lift the spacer plate off. Take the table off carefully after looking in all the nooks and crannies you can before lifting the table. I would have wanted to take the table off before purchasing it, just to see what is going on in there. But, alas, at an auction that is not a real possibility...
 

tjb

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Here's a link to a thread I started a few weeks ago on that very issue. Several guys here posted some invaluable information when I was looking. General gist of input was to be very careful. There are things that are easily fixable, but some things (like spindle, as Bob pointed out here and in my thread) that basically make the machine a high priced boat anchor.

I just missed out on the one I was looking at. The seller and I had agreed on a price but, understandably, he did not want to remove it from listing until I actually came to look at it. He sold it the DAY BEFORE I could get there. Bummer.


Regards,
Terry
 

Bob Korves

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Cosmetically, it looks very nice! Dig as deep as you can to see if it is true...
 

Cadillac STS

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Looks like a clean machine.


As far as moving it since you hired bonded professional movers I would not do anything to it until they had a look at it and recommend the safest way onsite.
 

GDS12

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Are there any special tricks to releasing the wire for the table? I think I read somewhere that you can lose the end of it and it can be a pain to re-route it... Also the owner said the rheostat was to control the strength of the grip on the magnetic chuck. Why would you ever need to reduce the force holding a part down?

Sorry for the newbie questions...
 

Cadillac

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I wouldn't rely on the moving company for anything other than moving the machine the fastest easiest way they can. They will not care other than damaging it to where the customer can see the damage. If it were mine I would be downloading a manual and reading up on it. The table has cylindrical rollers I believe, the table cables should be able to be disconnected at the ends of the table maybe bungy cord them once disconnected to keep them taunt. Block the head and lock the saddle if it has the provision. I had looked at that auction machines looked good. Was a bit far of a drive so I passed. Nice buy.
 

Bob Korves

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Electromagnetic chucks are quite useful for thinner and spindly parts, which can and will warp if they are magged down too hard. After grinding they will have a wavy surface or inaccurate features. That is much harder to do with a permanent magnet. Holding work safely but not too strong is a learning experience for new SG users. Use just enough force to mag it down, and block it with additional pieces to help contain it in place. Throwing parts is not good for your health, gives you a nervous tic, and usually makes you start over on the job. Be smart, be safe.
 

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EM chucks can also degauss the part, and some will hold much stronger than PM chucks. The preferred industrial choice when cost is not an object of concern.

Another trick for moving it without too much disassembly is to lift the table enough to put a wood spacer underneath (remove the bearings/cages first)! and then strap it down. If the table is moved separately, great care must be taken because the top and the bottom have critical surfaces and should be strapped to a wood carrier or pallet to avoid damage...
 

GDS12

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Thanks for the feedback. I am definitely not planning to trust the movers to make all the right decisions on moving this thing so that is why I plan to go there tomorrow to prepare as much as possible. I will bring as many tools as I think I need and some wood blocks etc... Hopefully we can get this stabilized to avoid damage while they move it. I did see that this chuck also degausses the part so you don't have to demagnetize the part like you do using a PM chuck. Pretty nice setup...

Gary
 

Dabbler

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I took my table off the SG and transported it in the rear seat...

If it comes with extra wheel adapters, make sure it is transported with a wheel adapter in place to protect the important tapered spindle. a ding on that and you are in for a world of hurt.
 

GDS12

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I was able to get access to the grinder this afternoon and removed the chuck and controller first. Then I removed the DRO scale on the side just to make sure it didn't get hammered during the move. After that I disconnected the cable (very easily done) and simply lifted the table off the saddle. You guys were 100% correct, the table had ball bearings underneath that were all running in a carrier (for lack of a better word). All looked pretty good and I think it is now ready for moving. Many thanks for the advice and observations... I will post more pictures once it is moved and I am cleaning things up before reassembly.
 

Dabbler

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oops - taking the chuck off could cost you some work. Clean everything up and take any corrosion off and see if the chuck sits nice - if it does, then you aren't too bad off. When it doesn't then you have to scrape to get it to sit nice. If it rocks at all, when you tighten it down, it can warp the table...

On that note: some guys use a big honking bolt on each end of the chuck, and really reef on the wrench. 1/4NC or 5/16NC or similar size and firm pressure is all you need. 'gronking' on the bolt is not advised.
 

Janderso

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I'm glad this thread came back to life.
I had Bob with me when we looked at the B&S 618 Micromaster I ended up buying.
Haven't moved it yet.
Taking the table off would be a good idea I guess.
Hadn't remembered that.
Better get some help on the move.
These guys know what they are talking about, I'm listening. Glad to have you.
 

GDS12

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I really needed to take it off because I want to get rid of the years of accumulated crud. Bottom is just dirty in narrow strips. All-in-all looks pretty nice with the exception of a poor wire splice between the chuck and the controller. I need to get into it and replace with one piece of cable...
 
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