Homeopathic Grinding

[george wilson]

Of course I don't just make tools. I make a pretty wide variety of things. For about 30 years my focus was upon guitars. In the 60's I had just gotten into also making lutes and a harpsichord.Happily,the harpsichord was seen by the right person,and it ultimately landed me the job offer as Master Musical Instrument Maker in Wmsbg. in 1970. It's nice when they solicit you instead of the other way around. I had gone to Old Salem looking for a possible job. That was pretty awful. The only thing they wanted was a way to manufacture things to sell to make money. No thanks!! After 16 years of Instrument making (In public),the director became aware of the tools I was making at home. He begged me for 3 years to set up a tool making shop behind the scenes. The craftsmen in the museum were using many in appropriate tools,including some awful looking saws and other things they had made without doing any research,and some having little artistic ability. Ghastly bad saw handles. Garlick blades. Soft as butter. So,from 1986 till 2009,I did that. I did not regret being out of the public very much. No longer did I have to answer "how long did it take and what does it cost,and could I have afforded one in the 18th.C." Many times a day!! And,the public's fascination with glue was amazing."What kind of glue do you use" was an ongoing question. And"What was the secret of Stradivarious?" (As If I knew). It's a SECRET!!!!!

[Mel Fulks]

I've had to make and regrind moulder and shaper knives for a long time and much prefer 1725 rpm machines even though some have been 12 diameter. I can see that someone in the top percentage of skill might prefer something faster,especially if grinding is an every day thing. At times I might not have to grind any thing for a couple of weeks ,then make several sets at one time. I think most amateur woodworkers will find 1725 rpm easier to learn on. Handgrinding anything beyond ones own handtools in commercial woodworking shops is getting less common .On the other side of the speed issue the purpose of the Tormek completely eludes me. I've tried them but much prefer bench grinder and hones.

[Andrew Hughes]

Love the first knife with the orangish yellow handle George,simply beautiful !

[george wilson]

Mel,a 10" grinder had better be slow or the wheel can fly apart !! They grind a good many of their own shaper knives in the millwork shop of the museum,for 18th.C.chair rail and other moldings. Commercial knives won't do.

Andrew,the handle is paper stacked Micarta. I was interested in it at the time. It starts out snow white and yellows like ivory. It has a grain that resembles ivory. I ought to change it to real ivory. The hilt is sterling silver. The blade is D2 steel. It is a high alloy steel that is quite abrasion resistant. They make metal cutting shears from it.

[Jim Matthews]

Okay - I give up, what's the sickle blade on a handle for?

I haven't got a clue.
It's just the sort of thing I would part my eyebrows with, trying to peel an apple...

[Winton Applegate]

I always meant to buy one of those for the tool making shop,but they cost several thousand

Don't be so modest. I am sure you could make a grinder up for yourself that would eat metal just as fast and probably add some nice inovations the stock tool purchasers could only dream about having.

[Winton Applegate]

especially to grind blank HSS metal lathe bits to shape

I agree with your responce to David.
I originally bought my Delta wet grinder that has one large wet slow white wheel and one fast small diameter dry white wheel for doing just that, grinding HSS metal lathe bits from blanks and sharpening them when dull.
Yep she's pretty slow and surprise, surprise, slower on the slow wheel than on the fast wheel.
http://www.amazon.com/Delta-23-700-U...et+dry+grinder

PS: David,
This doesn't mean you are off the hook though. No you are still evil for ATTEMPTING to point out the flipping obvious.
You are a bad man.

[David Barnett]

I've always liked bone micarta and have several tool handles and parts made from it. The older resins did age rather gracefully if you like that effect. The resins in the newer paper micartas don't yellow so deeply but also don't have that same ivory grain and look. Even more disappointing, they buff, at least to my eye, to a more plastic-y luster, seem softer and scratch more easily. My fossil ivories are mostly for jewelry and other precious objects.

I religiously inspect my wheels and always start grinders well out of the firing line and am content to wait prudently until they're up to speed and running smoothly. Small wheels can do surprising damage even at moderate rpms. Even pooled moisture from highly humid environments can cause an otherwise dry wheel to run out of balance.

Imagine what it was like when one of these Idar-Oberstein wheels went awry. Slow is one thing, mass another. And talk about holding one's nose to the grindstone.

[george wilson]

You should see pictures of grinding musket barrels. The wheels were about 6' in diameter,and 5 feet wide! They inserted a crank in the breech of the barrel,and hand rotated the barrel against the massive grindstone,skillfully rotating it and keeping the grinding on center with the bore of the barrel. Surprising what human skill can accomplish.

We have also seen octagonal rifle barrels whose flats are slightly hollow. There are some of those whose octagon flats were ground on these large wheels.

The posture of those cutlers goes back at least into the 18th.C.. I have seen 18th.C. illustrations where the knife grinders are laying on planks,completely over the tops of the wheels. That's how the French did it. Must have been a truly miserable job laying like these poor devils all day,every day,in poor lighting,and probably 10 hours a day,6 days a week. They were supplied with pretty rough forgings with lots of metal to be removed by inefficient abrasives.


Winton,it wouldn't be that hard to make one of those high speed belt grinders since we had a full machine shop. We just always had orders to fill

[Winton Applegate]

I went looking for it but couldn't find it. It was an old episode of a show like America's funniest videos but was about disasters and accidents. For instance one showed two guys in Taiwan or some place that were riding a motor cycle on the freeway and were impaled by a three inch pipe sticking off the back of a truck that slowed abruptly. The responders sawed off the pipe and transported the dudes with pipe in situ to the emergency ward. The dudes were conscious, sitting up and talking.

But that wasn't the vid i was looking for.
The one i was looking for was of the post hospital, post surgery interview of the guy who took an exploding bench grinder wheel to the face. There was a large portion of his skull missing but he said "it's all good" or the equivalent of that before people started saying that.
Not pretty, nope, nope, not pretty at all. Best to NOT grind hard on the side of the stone, which i think was what he had been doing, etc. Just the lightest touch on a tiny object and even then . . . pucker your krimpter.

[David Barnett]

I have seen 18th.C. illustrations where the knife grinders are laying on planks, completely over the tops of the wheels. That's how the French did it.

The Idar-Oberstein wheels were used to grind agate but here's a picture of the Thierry coutelliers when the wheels were still in use.

Must have been a truly miserable job laying like these poor devils all day,every day,in poor lighting,and probably 10 hours a day,6 days a week. They were supplied with pretty rough forgings with lots of metal to be removed by inefficient abrasives.

Truly. And shop accidents? If you were lucky, they just informed your widow.

Surprising what human skill can accomplish.

Isn't it ever?

Those barrel grinders remind one of the most ancient form of cylindrical stone wheels on Juggernaut. As a child I marveled at the celebrants throwing themselves beneath its wheels—a practice discouraged for some decades—in the documentary Mondo Cane ("It's A Dog's World") from old silent travel footage. Both the idea and imagery stuck with me and to reprise the cherished memory I'm again listening to the haunting theme music, better known as "More".

[Phil Thien]

As another SC contributor has tested this new methodology and found slower grinders up to 40% faster, I must accept this finding, as one simply cannot argue with science, with empirical evidence, as it were.

I feel so much better now.

In a previous life I wrote code for machines that ground/polished nuclear fuel rods.

At higher peripheral rates, self-sharpening becomes less effective. You can, indeed, reduce removal rates by increasing arbor speed.

[David Barnett]

At higher peripheral rates, self-sharpening becomes less effective. You can, indeed, reduce removal rates by increasing arbor speed.

You're right, of course. The right speed and feed rate is what one wants for any given abrasive and material. Many polishing processes on hard materials gain appreciably through slowing, finding that sweet spot or band, and too-high speeds can significantly damage materials through subsurface impact microfissuring and thermal fracturing. But for grinding tool steel bevels on machinery found in a home shop without drawing the temper? Well...

[Bob Strawn]

The case for homeopathic sawing is quite strong. A saw with 30 teeth per inch is of course much slower than a saw with 20 teeth per inch. If I reduce it to 5 teeth per inch, it becomes so powerful that is is hard to even draw it through wood. This pretty much proves the validity of homeopathic sawing.

While I have not proven it entirely, by my own experimentation it seems that the same principal holds true with abrasives. If you examine 400 grit sandpaper you will find that it has many more particles of grit per inch than 60 grit sand paper does. I know that this will come as a surprise to most of you, but the 60 grit paper actually appears to cuts faster even though 400 grit has way more edges to cut with. Oddly despite the multitude of edges on 400 grit sandpaper, when you use it the surface it was used on seems almost smooth. Yet with much fewer working edges, the 60 grit paper will almost instantly leave a surface that you can see the difference in. I have even heard of woodworkers who have taken this to extremes and will swear that they can work faster and produce a better surface while using no sandpaper at all. If this is true, the case for homeopathic abrasives is almost certain.

Bob

[george wilson]

The illustrations in Diderot(or one of the 18th.C. sources) show the French grinders in the same position. Stubborn people,eh.?