Looking for grinding wheels

My Overbeck uses almost the same wheel (12x1x5). Watch ebay, where you'll likely find what you need, and for a good price. I recall seeing several of the 14" when I was exploring some time ago. Be patient, they're not always available.

What material are you grinding? Your selection, especially of grain type, can spell a real difference. If you're using the wrong wheel for your application you'll get lousy results, and likely go through wheels one hell of a lot faster than you should.

Harold

The material is D-2 full hard (64R?) 8" dia. x 3/4" thick, 4"bore, round wire cutting rotary blades. The last 2 wheels I got on ebay for $10 ea. they are "I" hard 42 grit "Snow" white wheels. The best wheel seems to be "H" 36 grit. Surface finish isn't that important, just remove some material quickly. In fact, a rougher surface holds some lube. That D-2 is some tough stuff!!! The next batch of blades I make will be M-2...as soon as I can save that much cash.

I would suggest to you that finish could be part of your problem, assuming it starts life rather rough. It promotes premature breakdown of the sharpened blades. . I'll defer my opinion to your lifetime experience, however. I'm not familiar in the least with cutting wire as you do.

My biggest concern was that you may be using a silicon carbide wheel. It's more than apparent you are not. I'd have also suggested going to a slightly harder wheel, maybe a K or L, but your experience in this case indicates that's moving in the wrong direction. If you are experiencing wheel glazing, then I would be wrong. If you are experiencing excessive breakdown of the wheel, then I am likely right. Are you plunge grinding on the dies, or are you taking a deep cut with moderate side feed? I am

*not* a fan of plunge grinding, not unless you're running a Blanchard. You'll generally get far better service with fixed depth and moderate side feed. It not only moves metal just as fast, but leaves a superior finish.

Why are you getting short wheel life? Loading? Glazing? (They're not the same, but often difficult to distinguish) Breakdown?

Harold

You said a mouthful! The Arter rotary grinder rotates the blade centered on a mag table parallel with the floor. The table is set to 1.5 degrees from perpendicular so that the blade gets ground with a slight concave shape. The 14" wheel is on a ram that swings back and forth over the rotating table with the wheel perpendicular to the table. At the end of each stroke, the table is lifted by .0005" to .005", depending on the setting. When I mention a "rough" surface finish, I mean that it's not like a mirror.

Yes, it appears that the latest wheel seems to be glazing excessively and leaves a funny pattern on the surface. I turned the job over to a tech months ago with the intention of having him handle it. I had one unmarked wheel that I got surplus at a supply shop for $20 that ground the blades nice! It cut a lot of stock fast, ran cool and didn't need to be dressed so often. We dress with a single point diamond. But that wheel is gone now after doing about 200 blades. DAMN! I wish I could figure out what it was! The cost of the wheel is secondary to the cost of the labor so I'm willing to wear out the wheel to get the job done faster. Do I want Al Oxide, soft and coarse? I've come to the conclusion that I know less about grinding now than I used to and the more I learn, the less I know...pretty soon I will know nothing!

When it wore out, did you save what's left of it? (Please say yes...)

A little forensic work by a grinding wheel expert might well be worth a few bucks - call up Norton (name picked out of a hat) and see if they can do it, or if they'll refer you to one of their retired engineers who wants to pick up some beer money, and ship them the wheel to figure out the composition.

Sometimes the parts books are hopeless, and you have to haul the greasy old part to the supply house and plunk it down on the counter. That's life. ;-)

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Those sound like the dimensions of the grinding wheels my Covel OD grinder uses. They are available from Norton, Carborundum etc.

A buddy who runs a grinding business may have some spares. Ill ask him this coming week. I have about 5 new wheels that came with the grinder.

Gunner

"Considering the events of recent years, the world has a long way to go to regain its credibility and reputation with the US." unknown

Of course I have the old one, I still have the old EVERYTHING!!! It might grow back. (Good Idea, I'll put it in my pocket next time I go to the store)

See if he needs any brushes.

You'll have to study the wheel to determine if it's loading, or glazing. If the wheel appears to have swarf embedded deeply within the wheel, especially after dressing off a few thou, it's likely not open enough to allow for the swarf to pass in to, and out of, the wheel properly. If you find signs of metal attached in clumps, that's also a fair sign, although that could also be a sign of the wheel being glazed and swarf burning to the wheel. This observation will tell you if you should go harder or softer, assuming it's glazing.

Both conditions cause the wheel to leave a burned and irregular surface, and, of course, cut hot as hell, leaving signs of burning, perhaps even stress cracks in the surface. You should see signs of a scalloped surface, regardless of which condition.

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That would be my initial thought. ALOX for sure, and relatively soft as well, so the wheel breaks down as it dulls, but not to quickly, which makes grinding more difficult. Coarse makes for faster stock removal, but a lesser finish. The spread of the specs of a recommended wheels makes it difficult to be exact, as does the material in question, but a hardness range of H through J would be acceptable as a starting point(according to a reference book)-----H being softest. Probably a 46 grit 32A is a good choice, and maybe an 8 vitrified bond. You're going to have to experiment until you land on the right wheel. This information is within proper range as a starting point. Shame you don't have the data from the old wheel.

Chuckle! Imagine how I feel after being away from precision grinding for so many years. I can't wait to get the shop up and running and re-acquaint myself with the machines, especially the grinders.

Good luck, Tom. Let us know how it goes.

Harold