Questions about grinders

Hello. I've got a background of being a hobby machinist at home with a 1954 Bridgeport and metal lathe. I've read and watched videos about grinding, but have never done so. I work as an industrial/mechatronics mechanic/technician, also learning to program PLC's. Because of my background, work has posed the question about whether we should get a grinder. The place I work makes shredders among other things, and cutters have typically been subbed out, but we're trying to bring more things in house.

So, I've been asked if this particular grinder is worth it, being made in Taiwan and all.
https://www.mscdirect.com/product/details/62364054

I'm fairly certain they are looking at that one because of the size of the objects we'd need to grind. I know old Clausing machines are good, not sure about the current ones. Any alternatives in that size range?

I'm sure I'll be doing a lot more reading about grinding to give them accurate information, but is there anything that isn't obvious to a grinding noob that would be a consideration in hidden costs, considerations?

Thank you in advance for any info.

Maybe I missed it but I don't see a magnetic chuck listed. No experience with this machine.

While you can mount fixtures directly to the table, if you're grinding for flat you need one. I prefer the fields running crosswise .

Dave

It's going to depend upon your expectations and requirements. Are you certain you need all the 40" of table travel to grind your products? That increases the price of the grinder & wheels quite a bit.

Next would be whether you really need CNC controls or is semi-automatic good enough?

How about expected level of accuracy? Flat or are there forms/profiles to account for too?

Most of my experience has been with grinders that were either smaller, older, or both. The larger wet grinders I've used were old Thompson, G&L, or other makes that are long gone and/or worn out. The remaining makers that offer New grinders in that size are unfamiliar to me. I'm a bit leery of products from any of the brands I'm not familiar with as many machines are now designed/made with as many cost savings (cutting corners) as possible that aren't always readily apparent (cheaper spindle bearings and castings). There was a company I worked at (Thomas & Betts) that purchased several new machines (lathes and mills) based on price and incompetent decision makers. The machines (Knuth I think) were regarded by a member here from Germany as the German equivalent of Harbor Freight or Enco. I don't have a very high opinion of the machines sold by MSC that I've seen. The grinder you've posted may work ok or turn into a headache 3 years later with bad bearings, worn ways, or hydraulic issues. It may also be the best buy on the market but that would have to be proven to me first.

I fully understand that everybody has a budget and that new purchases get the depreciation schedule. Having said that if it has to be new I've preferred Okamoto or Mitsui grinders and (I would hope) are still making good quality machinery.

If those are out of the budget I'd look at a good used grinder that's either been rebuilt or is still in good condition. Condition means far more than the name on it in used machinery.

If used isn't in the cards then you'll have to take your chances with new machinery and that's a roll of the dice unless someone else can offer personal experience with the lesser known and/or newer makers. Taiwan does make some excellent machinery (same as China can) but I don't know who they are or have any experience with their larger surface grinders to have a valid opinion to offer.

There are some other members here like Cash and Michigan Buck that have more recent experience with larger grinders to help with your decision, hope they post in this thread. I'd be interested in following your decision and how it works out. Good luck.

winger said:

Maybe I missed it but I don't see a magnetic chuck listed. No experience with this machine.

While you can mount fixtures directly to the table, if you're grinding for flat you need one. I prefer the fields running crosswise .

Dave

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That's a good catch. I can't see it listed anywhere either. I have done some googling and found that there is also a Kent that's a similar size, and a Chevalier as well. Not familiar with either brand.

ygolohcysp said:

That's a good catch. I can't see it listed anywhere either. I have done some googling and found that there is also a Kent that's a similar size, and a Chevalier as well. Not familiar with either brand.

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-I've run both in smaller models and the only thing about them I liked was that they were newer than some other grinders in the shop. I really didn't like the ergonomics or "feel" of them but that may just be my biased opinion. No idea about durability or longevity for either.

Grinders are often sold without a mag-chuck because everybody has a different preference or application.

I do know the answer to some of those questions. When I was first asked about grinders, I told them that to my knowledge, grinders were another level of precision above machining. They really only expect +- .001", and to my knowledge, all the parts we would need to grind would be flat. I think we would need close to the 40 inches of travel, and potentially the 16" of travel as well. Not just the cutters, but also the end plates that hold the bearings for the shafts I believe.

At least one of those other brands I listed specifically listed using ABEC 7 bearings, and that's a good point. I shouldn't make assumptions that other brands would use good bearings just because I know they should. Thank you very much for the info! I'll update when we eventually make a decision.

You're correct in stating that grinding can/should be another level of precision than milling/turning. Any decent grinder should be easily able to handle the +/- .001 in accuracy just by design/nature of the machine/process. I would like to say that achieving that tolerance over the entire 40" of travel may/can be difficult because:

1) Surfaces that have to be referenced over what length to what feature? Overall or just relative to nearby features?
2) Heat, larger and/or more exotic materials can generate a lot of heat and be a PITA to grind accurately
3) Locating the work parallel to table travel creates problems the longer the wheel is in contact with the work
4) Larger grinders have enough HP to throw large pieces. Fixtures for locking in the work better be real solid
5) Thermal and/or residual stress is often released in grinding (similar to milling) and things can get ugly real fast.


I applaud your company being willing to explore bringing this in-house and you for seeking out information on this. Grinding is not just a different process it has another set of guidelines too. The ABEC 7 bearings are what I'd recommend if you plan on keeping the machine for long term. Some companies subscribe to the pump-and-dump approach once the depreciation is finished and purchase on price point alone.

Check out this video from Don at Suburban Tool YouTube.
It is another option from buying new,rebuilding an older top line grinder to new specs.
With your specs can a Blanchard grinder be of use?If you have a large volume of parts it will be a lot quicker.

Don has a lot of very good videos on grinding,well worth watching.

Be very cautious about any firearm with a messed with serial number. There really is only one reason to file off a serial number. It would likely be seized by LE or ATF.

ygolohcysp said:

I do know the answer to some of those questions. When I was first asked about grinders, I told them that to my knowledge, grinders were another level of precision above machining. They really only expect +- .001", and to my knowledge, all the parts we would need to grind would be flat. I think we would need close to the 40 inches of travel, and potentially the 16" of travel as well. Not just the cutters, but also the end plates that hold the bearings for the shafts I believe.

At least one of those other brands I listed specifically listed using ABEC 7 bearings, and that's a good point. I shouldn't make assumptions that other brands would use good bearings just because I know they should. Thank you very much for the info! I'll update when we eventually make a decision.

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Does the company send the work out now ?
How is it done now ?

It sounds like a Blanchard grinder (or other name, same design) is needed.

where in Pa ? I am near Erie.

There are a lot of good us made machine out there at a tenth of the cost, G&L comes to mind, look around...Phil

That is a good name brand and likely a very good machine. You may pay $10k for a clunker to good, and $20k for top condition older 1640 machine. I have not priced new USA grinders so cant say if that price is good but it seems good. Guess you might look at some USA new and like new machines.
I like oil and iron scraped ways on a grinder but don’t know if anyone still makes them now a days.
USED Kent KGS-510-AHD 20"x40" Hydraulic Surface Grinder (UM) | eBay 1994 @ $20K
I would advise to review the grinding you send out and quantity of each size. Surface grinders are mostly for flat work and flat form work. Grinding machine bases flat would be a surface grinder task. Giving up floor space would need enough work to make that floor space loss worth it.
Magnet chucks vary so most surface grinder are sold with the buyers choice added. That saves taking one off pre shipping, or sold with no chuck..IMHO best to grind a chuck after the machine is set in place.

G&L-?.. likely nobody makes a surface grinder as good as would be a top shape G&L or other top name grinder. But I did see one G&L that would dome low at both ends of long travel..it was set up with two magnetic chucks and production run at near full travel.

Used & reconditioned reciprocating surface grinders, since 1981.

Good to have a seasoned grinder hand/master along when looking at used machines.

Tell us about the part you wish to grind. Size, tolerance, material, quantity, and amount of material needed to remove are a start. Without those things any recommendations are a shot in the dark.

A real decent family of surface grinders. It is a private label and paint.
Maybe better than the old Clausings which were not the best surface grinders made here.
Do you need one this big?
A Blanchard just big enough to hold this size part will not hold size/flat with this machine. Just no way, It will be faster in stock removal by miles.
Now a really, really big Blanchard where you put four or six of these parts around the chuck and not near center, different. Those machine rare and very huge.

I do not think you would be unhappy with one other than learning to make a surface grinder work which is never easy.
They are not milling machines or lathes. Art and pain. Expect lots of pain.
Bob

I found a new cylindrical for Georgia Mike (forget his name, posted on alt.machines a lot) and he was happy. New not-as-good can be better than wonderful-but-wornout. I would go old and wonderful, then spend the next two years rebuilding it, but I'm not very smart.

If you like pm me.

The vertical spindle ones are cool but very rare, except for automotive, which isn't super accurate.

Update time!

Okay, based on some of the information here, and based on looking at some of the cutters and asking more questions about the amount of material expected to be removed and such, I determined that a blanchard grinder likely is the best option. So we just purchased a used Chevalier FSG-1224AD, which isn't a blanchard grinder. LOL But that's fine. Amount of material removed has been addressed, and we're going to be starting with much smaller cutters.

So, now I'm going to have to invest a bit of time, and start learning about grinding wheels, which type I'll need for cutting prehardened tool steel, if I'll need a different type for re-dressing the magnetic chuck (assuming I'll have to do that after the machine has been moved, set in place, and leveled). I'll also need to start learning about the actual process of grinding, speeds, depths of cut, step-overs, how often to dress the wheel, etc.

I of course plan on doing a lot of research with google, books, youtube, etc. If anyone knows of any particularly good resources for a newb, I'd gladly accept though. Again, I do have experience with machining on manual Bridgeports and Lathes. Just no grinding experience.

Aside from what you learn on the internet, keep a small notebook of your own observations noting wheel, DOC, step-over, material being ground, etc. when you grind. Your own results have information not always mentioned by somebody and/or can provide the basis for asking questions when something doesn't produce the desired results. Stay safe, good luck.

Okay, one last question. I know with most machining, there are tool reps that can point you in the right direction for cutting tools and feeds and speeds based on your goals/material. Unfortunately, I've never bothered to find any for my machining experience. Would those reps, or others, do similar for grinding wheels/setups? And if so, does anyone happen to know a good rep for an area just a tad north of Philadelphia?

I've already done some reading, enough to know that diving into it more is going to be an exercise in making my brain feel like it's melting. But meh, it was the same way when I learned how to to program PLC's to completely program entire industrial systems in about a week. I do like learning.

Don't know any reps in your area but every major company has reps to help with technical questions in the interest of you placing an order with them. Some of what you'll have to figure out is how often a particular application/job is going to occur and whether a more expensive solution/wheel is worth the price. CBN wheels are great for some hardened materials like D-2 and M-2 but if I only had an occasional D-2/M-2 piece then an AO wheel (with a VFD) offered a greater cost savings. Some reps are invaluable, some are just BS artists like any other salesman. Trust advice from those trying to sell you something? With a grain or two of salt sometimes. Weeding out solutions with marginal advantages may be your biggest task. Group the materials to be ground into classifications along with expected surface finish. Sub-divide those groups into flat grind or contour/profile jobs. Wheel grain size, friability index, bond, and type of abrasive will begin to emerge. This is where your notes will also help. The more metal removed in the milling machine the faster the finish grind, but there has to be enough left on to remove de-carb, warp, and adjust for detail geometry location. This is where you begin to dial in the process for repeat jobs and co-ordinate the milling and grinding process. How much/little can you leave on before heat treating is the balancing act. Once again, your notes from jobs can help point out problems/solutions/questions to help. I probably don't need to mention that a good surface plate and indicators are a must for accuracy when flat/parallel/square/location are important. All other instruments/tooling will depend upon what you're doing and what you do/don't have. If you have a favorite base for attaching your indicator I would suggest modifying it so you can check for perpendicularity of plates/blocks. There's several ways to do this if you search for "checking squareness" or words like that. What you have going for you is that you're willing to learn, you'll do well. Ask questions, many good grinder hands here. Good luck, be safe.