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I don't think they were obsessed with flatness, but apparently apprentices were restricted from using the grindstone for some time. I don't know why that is, but maybe preserving what little semblance of trueness was a concern.
Again, while not obsessed with flatness, they did have processes to deal with stones with a hollow.
Exercises in Woodworking 1890(Well after this country was built, but a long enough effing time ago)
If my "1000" grit stone is not the same shape on top as the "5000," then it takes a lot longer to hit the edge all the way across. I imagine a grindstone with convex shape hitting any "flat" chisel or plane iron, enough skill could result in a usable tool afterwards. When the stones, bricks or wheels, get to a point where they're concave, I can't imagine how useful that is.
When everything is flat, I literally have nothing to complain about in terms of sharpening time. With the finer grits that are removing less material, it starts to get imperative that only the material that needs to go is removed. I would *like* for the whole process of sharpening to happen as quickly as it take to walk over to where the stones are, but that's where power tools come in, I guess. I have my eye on some, but since I don't absolutely need them, I can't justify them, at least right now.
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Oh, and still waiting for the picture of the sharpening tool you made, Timberwolf!
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(01-15-2020, 03:07 AM)Robin Dobbie Wrote: Oh, and still waiting for the picture of the sharpening tool you made, Timberwolf!
Timberwolf, can you also post a link for the diamond laps you mentioned (that are cheap, don't need flattening, and last a long time)?
Steve
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I don't know what Timberwolf has, but I just use a regular 400-grit diamond plate. DMT, Eze-Lap(not the plastic two-sided), or Atoma should work. I got the Atoma since it has a discrete layer that can be removed so you can easily do something with the rest of the plate if the diamonds become damaged or whatever. I paid like $60 for it. Lee valley has them for $136 which is ridiculous, but whatever. They had them for $99 for a couple of days, but they went back up again? Sheesh. I just did Amazon for $63. But I think you can get them directly from Japan, too, if you want to wait a few weeks and pay $75.
I don't how precisely flat they are, but when I hold my straight edge which ever way on the surface, it looks perfectly level. Good enough. I wasn't about to pay $500.
Also, Veritas plates are $30 at Lee Valley. They were $25 literally 2 days ago. Still, they're .005 across the surface and they claim they last a lifetime. Bring your own abrasive.
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01-15-2020, 09:20 AM
(This post was last modified: 01-15-2020, 09:22 AM by Timberwolf.)
(01-15-2020, 03:07 AM)Robin Dobbie Wrote: Oh, and still waiting for the picture of the sharpening tool you made, Timberwolf!
......................
This is slow-speed belt grinder Mark 1.....I have since simplified it drastically, making it much easier to build..., I need to replace the platen with one made out of steel, because the grinding dust wears a groove in the aluminum platen as shown...It is being driven with a 1/4 hp motor which I intend to replace with a sealed 1/6 hp motor I have...With a "crowned" drive wheel, belts never need to have the tracking adjusted, after they have been trued..All that is needed is the initial adjustment which is done by " skewing" the motor so that the belt runs in the center of the idler...I made a leather strop belt for it but you can buy a commercial one.
Another Woodnetter ..{ Mark..AKA "Cletus" } made the MK II version of this grinder/polisher and has photos of his...maybe Mark will see this and post the photos. I also mailed Arlin the basic unit but don't know if he ever finished his or not. In that one, I stacked three sealed ball bearings and used them for the idler roller. The bearings are cheap and can be purchased from ebay dealers..The other parts/materials needed are available from the Borgs.
Often Tested. Always Faithful. Brothers Forever
Jack Edgar, Sgt. U.S. Marines, Korea, America's Forgotten War
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01-15-2020, 09:42 AM
(This post was last modified: 01-15-2020, 09:53 AM by Timberwolf.)
(01-15-2020, 08:55 AM)arnman Wrote: Timberwolf, can you also post a link for the diamond laps you mentioned (that are cheap, don't need flattening, and last a long time)?
.................
Sure...Here's a link to the laps on Ebay, but you can also get them on Amazon for about the same price or less...The plates are about .090" in thickness and are zinc plated steel.. Diamond is electroplated on one side. The 150mm {6"} is bored 1/2"....I have one with 3,000 grit but I am sure they are available even finer than that. The coarser laps really cut..No steel is too hard for them.. As the laps wear, they leave a finer finish. You can use them dry but I believe they last longer and cut better when lightly lubed...I use a few drops of mineral or baby oil. The heat build-up is negligible...IMO at ten bucks each, they are a terrific buy. You get a lot more diamond for your money than the rectangular diamond hones and they don't have to be motorized in order to use them..you can use them just like the more expensive rectangular flat hones sold for sharpening...even though they are round discs.
https://www.ebay.com/itm/Drilax-6-Inch-P...SwonJbr9zD
Notice the swarf mixed with the baby oil on the lap...just a few strokes of the chisel produced it...The lap is 3.000 grit...Did I mention that these things cut???????
Often Tested. Always Faithful. Brothers Forever
Jack Edgar, Sgt. U.S. Marines, Korea, America's Forgotten War
Get off my lawn !
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Wow, and the diamonds are electroplated on there. That's the good way. As opposed to just adhesive. I didn't catch whether or not they were monocrystalline, but at that price... gotta be some kind of market dumping or something.
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Oh, and nice grinder. Looks ideal even for making knives and such.
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01-15-2020, 01:19 PM
(This post was last modified: 01-15-2020, 01:20 PM by Timberwolf.)
(01-15-2020, 11:15 AM)Robin Dobbie Wrote: Oh, and nice grinder. Looks ideal even for making knives and such.
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Knife making is why I built it..I enjoy carving and working with exotic woods and metals and needed small, a slo-speed machine and there wasn't much to choose from in that regard.
picture hosting for forums
Often Tested. Always Faithful. Brothers Forever
Jack Edgar, Sgt. U.S. Marines, Korea, America's Forgotten War
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01-15-2020, 05:53 PM
(This post was last modified: 01-16-2020, 10:58 PM by arnman.
Edit Reason: Edited to say gap is too SMALL for 0.0015 feeler gage
)
Quote from Robin Dobbie:
"Also, Veritas plates are $30 at Lee Valley. They were $25 literally 2 days ago. Still, they're .005 across the surface and they claim they last a lifetime."
I always wondered if "0.005 across the surface" was a typo on their part. That seems like a fairly big gap under a straight edge on a relatively small surface. I can easily see light under a straightedge that is too small for my 0.0015 inch feeler gage.
Steve
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