Diamond wheel tool grinder

We are setting up a "family machine shop". Way back when, during an
ebay buying binge, I bought a nifty old diamond wheel tool grinder.
I'm having a senior moment and can't remember the brand but it is good
old 'murcan iron. It has a single phase 110v motor.
My understanding is that its purpose on earth is to cut carbide lathe
tools. Now that we've recently acquired a tiny Enco lathe and mill,
the tool grinder may cease being an objet d'art and resume a practical
life.
We are all clueless, rank amateurs. So forgive the stupidity of my
questions.
But here's one: Do we really need this grinder? I don't know how
long a lathe tool lasts. Nor do I know how much they cost. In other
words, since we don't have an industrial shop full of union
machinists, is this tool overkill for our needs? Or is it a valuable
addition to a small shop?
Thanks,
Vernon
Reply to
Vernon
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To clarify: This is not a fancy multi-head tool maker's grinder. It is not too different from a bench grinder. However, it has a vertically spinning diamond wheel, one side of which, has a table that can be adjusted for angle and distance from the diamond wheel. The work is fed into the face of the diamond wheel, not the edge. My understanding is that its exclusive purpose is the grinding of carbide lathe "inserts".
V
Reply to
Vernon
Note that you should *not* use a diamond wheel on normal steels, including HSS which represents a lot of lathe bits.
HSS bits come as blanks, which you need to grind to the shape needed for your task of the moment. You will need a normal stone, not a diamond stone for these.
You can have two kinds of carbide late tools:
1) Brazed insert tooling. A small piece of carbide is brazed to the steel shank with some overhang so you can grind the carbide without touching the HSS (which would ruin your diamond wheel, and any other wheel would be pretty close to useless on carbide.
These can dull and need touching up. They come premade in several shapes -- right-hand cutting, left-hand cutting and other shapes.
2) Indexable insert tooling. The carbide drops into a pocket and is held down by one of several techniques. When it gets dull, you loosen the hold-down, and rotate to the next point. Each point will project the same distance, so you don't have to re-adjust the position of the tool when you index to the next point.
You *could* sharpen these -- but you would lose the benefit of repeatable projection, and many inserts of this type have grooves to act as chipbreakers and for various other purposes, and grinding would change the relationship of the edge to the grooves -- so it is better to not grind on the inserts.
So -- the diamond wheel grinder which you have could be used for sharpening brazed insert carbide tooling, and for changing the shape somewhat for special purposes -- but you will need another grinder for normal HSS tool grinding.
Good Luck, DoN.
Reply to
DoN. Nichols
Actually, you can use it to grind any carbide bit, do not use for high speed steel bits as you will destroy the diamond wheel. If it were mine, I would look into replacing the diamond wheel with a similar one made of carborundum or aluminium oxide. This would make it very useful. Gerry :-)} London, Canada
Reply to
Gerald Miller
Don and Gerry. Thanks. That was very helpful. I will attempt to educate myself as to the differences between applicability of HSS and carbide as regards anything we are likely to do. Steel is something I understand. At least, far better than carbide. So I will look into replacing the wheel.
V
Reply to
Vernon
No.
You'll never need it; carbide lasts forever, even when you crash the tool into the chuck jaws.
Send it to me - I'll dispose of it safely for you.
Reply to
_
On Mon, 20 Oct 2008 19:47:36 -0700 (PDT), the infamous Vernon scrawled the following:
I'm not a machinist, but I can tell you that it's a valuable addition to the shop. Learn to sharpen your own tools and save tons of time and a bit of money. If you can adapt it and learn to use it for your kitchen knives and wifey will love you all the more. What's not to like?
An Old Tool is a Good Tool!
-- "Politics is the art of looking for trouble, finding it whether it exists or not, diagnosing it incorrectly, and applying the wrong remedy." -- Ernest Benn
Reply to
Larry Jaques
On 21 Oct 2008 04:58:11 GMT, the infamous "DoN. Nichols" scrawled the following:
I thought -speed- determined that. I adore static diamond plates (both EZE Lap and DMT) and sharpen everything I own on them. If his diamond wheel is geared down like the woodworking sharpeners, it should be great on HSS, too, shouldn't it? Isn't it heat which melts the steel's carbon into the diamond (or vice versa)?
You'll get my diamond plates away from me when you pry them from my cold, dead hands.
-- "Politics is the art of looking for trouble, finding it whether it exists or not, diagnosing it incorrectly, and applying the wrong remedy." -- Ernest Benn
Reply to
Larry Jaques
I'm not a real machinist, this is my experienced amateur, prototyper, occasional toolmaker's opinion.
I have a pedestal grinder set up with one coarse aluminum wheel for general grinding and HSS tool bits, the other side is a fine silicon carbide wheel for carbide bits and light finish grinding on steel. I've seen many grinders like this at machine shop auctions.
Another small bench grinder has one wheel only for TIG tungstens and a diamond wheel for finishing the edge on carbide.
As mentioned you can't grind much off an insert, but you can take all the rough cuts and then touch it up for the finish passes.
I use the offset brazed threading bits rather than inserts when I need to thread close to a shoulder, and the diamond wheel is useful for keeping these sharp. I'll touch it up with a hand lap or the diamond grinder before the finish cuts if the threads finish doesn't look smooth enough after roughing.
Jim Wilkins
Reply to
Jim Wilkins
I've got a diamond grinder that sounds similar to the OPs and I use it on carbide and HSS. It is normally referred to as a diamond lap and it has a very fine wheel and leaves an almost polished finished which is much finer then any grinding wheel I have used. I don't use it for stock removal as such just to give the shaped tool a final finish which is much better than left by my other grinding wheels. It doesn't seem to have effected the wheel but maybe that is to do with not running the tool hot.
Reply to
David Billington
Sounds like it could be a Glendo. Very nice & very useful. Does it looks like one of these?
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They run at a slow speed, and can be used for steel as well as carbide. The tool rest mak s it possible to grind special bits to accurate & repeatable angles.
Doug White
Reply to
Doug White
Think of HSS as a cabinet scraper or sandpaper, compared to carbide, being a bulldozer, in a production operation.
Steel is something I
Gerry :-)} London, Canada
Reply to
Gerald Miller
On Tue, 21 Oct 2008 18:45:45 +0100, the infamous David Billington scrawled the following:
What's the RPM of the diamond plate? The woodworking models are slower, but it looks like they've gone to sandpaper disks now. Hmm...
Work Sharp 3000 = 580rpm Tormek T-7 = 90rpm (vertical, like a standard grinder with a wider stone. It's the Cadillac of sharpeners @ $600ish.) Veritas = 650rpm
-- "Politics is the art of looking for trouble, finding it whether it exists or not, diagnosing it incorrectly, and applying the wrong remedy." -- Ernest Benn
Reply to
Larry Jaques
On Wed, 22 Oct 2008 00:15:57 GMT, the infamous snipped-for-privacy@alum.mit.edu (Doug White) scrawled the following:
Hayseuss Crisco! $650 and $1300? If the Tormek is the Cadillac, this must be the Rolls Royce series.
-- "Politics is the art of looking for trouble, finding it whether it exists or not, diagnosing it incorrectly, and applying the wrong remedy." -- Ernest Benn
Reply to
Larry Jaques
[ ... ]
If the speed is kept slow enough -- and the pressure low enough as well, you should have no problems. But I don't know the speed of the tool which he has -- that was not specified in the thread so far AFIKT.
The diamond's carbon migrates into the steel, wearing the diamond quite rapidly, and hardening the steel at the same time. :-)
:-)
Enjoy, DoN.
Reply to
DoN. Nichols
2850RPM , it's one of these
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. I don't know what the grit is and the designation on the spare wheel doesn't make any sense to me regarding grit size.
Reply to
David Billington
=A0 =A0 =A0 =A0-- Ernest Benn- Hide quoted text -
I suddenly remembered that the brand is "Hammond of Kalamazoo". Here is an ebay ad for one similar, but not identical, to mine.
V
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Reply to
Vernon
snip------
Silicon carbide wheels are not intended for use on steel, for the same reason that diamond is not intended for use on steel. Because the temperature at the point of contact is high, carbon from the silicon carbide migrates to the steel. The effect is to dull the grains quickly---so the wheel glazes and ceases to cut. You apply more pressure, which in turn creates more heat and accelerates the collapse of the cutting capability of the wheel.
Aluminum oxide will out-perform silicon carbide, in spite of the fact that it is much softer. It's the recommended abrasive for grinding steel.
Harold
I've seen many grinders like this at machine shop auctions.
Another small bench grinder has one wheel only for TIG tungstens and a diamond wheel for finishing the edge on carbide.
As mentioned you can't grind much off an insert, but you can take all the rough cuts and then touch it up for the finish passes.
I use the offset brazed threading bits rather than inserts when I need to thread close to a shoulder, and the diamond wheel is useful for keeping these sharp. I'll touch it up with a hand lap or the diamond grinder before the finish cuts if the threads finish doesn't look smooth enough after roughing.
Jim Wilkins
Reply to
Harold and Susan Vordos
snip----
I'm going to assume that the model you have is also a high speed machine---where the diamond wheel rotates above a couple hundred RPM. by the way, Hammond is a well respected builder of diamond grinding machines. You are fortunate to have one of them.
Do NOT use the diamond wheel on steel of any description. As DoN mentioned, diamond, at high temperature, is destroyed when used for grinding steel, which has an affinity for carbon. The steel suffers almost no consequences, but the cutting edge of the diamond is rounded quickly, rendering the wheel less capable of cutting. More pressure is applied to overcome the problem, raising the temperature ever higher, degrading the diamond more severely. Norton has performed extensive testing and has documented the failure of diamond when applied to steel at high temperatures.
When you use the wheel for re-sharpening brazed tooling, insure that you have used an aluminum oxide wheel to relieve the steel to the side and below the carbide insert. You can do that easily by grinding a relief angle that is slightly greater than the desired relief angles of the carbide tool.
Harold
Reply to
Harold and Susan Vordos
Thank you. Is there any reason not to mount aluminum oxide on one end and carbide on the other? I think they're 6" wheels. V
Reply to
verntuck

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