Whetstones Flattening Machine?

Looks to me...

John in NM


>like them things cost as much as or more than a new surgical stone. Why bother? How not flat could it be anyway, as it sounds like you were hand lapping it? Toss it or give it away and move on.

But as far as your actual question goes, it might work with passes light enough. Use kerosine rather than water, so you don't have to mess with the plastic. I don't think the minor amount of swarf would be a problem if you keep it wet enough and clean the machine table thoroughly afterwards. I wouldn't bother with a drill press personally, probably would introduce more error than what you're trying to remove, what with the quill bending slightly under the sidways pressure.

I used to know a guy who made mineral thin sections on microscope slides for petrographic analysis. Can't remember how thin now, but thin enough to be able to see through most minerals. He was able to do this freehand on a 36" powered lap and somehow acheive a consistent and correct thickness. Nothing like 30 or so years experience.

John

Re: Looks to me...

woodburnbob


>Thanks for the suggestions and questions, John. The grinding heads would cost more than a stone or two. I've got a box of stones I've picked up over the years; they all need attention. But that's not the core reason behind this.

Why bother? 'Cause I want to. In part, I'd like to see if I can do it. Nothing terribly practical about anything I do. But, glad you asked. One of the greatest motivating forces in my life has been someone telling me I can't do something, or shouldn't, or shouldn't bother. I feel like I learn something about the task at hand and about myself even from my long, drawn-out, miserable, stupid failures. Perhaps I'm just oppositional and stubborn.

Oh, the other part is that it makes me feel better trying to make useful something defective or old and worn, sort of regardless of the effort and cost, and sort of regardless of how necessary the thing is in the first place. Instead of doing something else with my time, I do this.

I'll keep the kerosene in mind. I suspect your right about the rigidity of a drill press.

Still kind of hoping someone might pop up with some first hand experience with the grinding heads or the process.

So wouldn't it be similar to a big end mill?

John in NM


>Just using much lighter passes? Maybe though those are designed to go on one of those carbide grinders that look like bench grinders with a table on the end. I wonder if you can find an arbor to mount them on that will go in the mill. I've used one for slot cutters and things like that, but maybe a bit too big.

I've only ever tried freshening up a soft arkansas on a well used 180 grit 8" diamond lap (by hand, lap not moving). I had been using light oil for honing rather than a penetrating oil, and found that it gummed up pretty fast. Worked quite well, though I've never attempted to quantify the flatness with this method.

Sounds like you've got plenty of stones to experiment on too.

Good luck with it,

John

Re: Whetstones Flattening Machine?

David Barnett - SW Florida


>Bob, I can lap a few stones by hand in an evening. Although I have a variable speed rotary flat lapping/faceting machine with water drip, my good stones (and I have a few) get hand finished and it's nearly as fast (more consistant for larger stones, too). Since I also like to deglaze even more often than flatten, I prefer using the appropriate grit for the final surfacing. Yesterday, I moved two very heavy boxes of chert which I've collected over the years for hones and polishing points; Novaculites, jaspers, and so on. Some of my slips look pretty enough for jewelry, heh.

While it's easier to buy machines designed for slab lapping, many do enjoy making their own. Used machines cost far less than new, of course, and even less than some homebrew. Never seen anyone use laps like those, though. Anyway, for once or twice a year, hand lapping would do the job, I'd say.

BTW, I'm talking about loose grit lapping.

David Barnett - SW Florida

Re: Whetstones Flattening Machine?

Thom D


>Are you talking about those machines that have a turntable ,and you put sltone on them and they spibn against a fence and there is sc grit on the turntable to flattent he stones?

What about a surface grinder with a diamond saw blade?

Re: Whetstones Flattening Machine?

woodburnbob


>Right. Seems like the more I think about this, the more I don't know what I'm talking about.

I started out looking on the web at circular diamond blades and then noticed those diamond grinding heads. This pushed me into a day dream.

Of course, I have no idea of the tolerances or what might happen with a little heat or torsion. It simply occurred to me they might buzz off a few thousandths from my 2X8 stone, given the right setup.

The problem with the black Arkansas stone I'd most like to fix is that it's domed/convex. I have no luck with hand lapping convex surfaces flat...whether we're talking stones, plane blades or plane soles. Thus, I've rationalized my personal failings into a broad general theory that it's geometrically impossible, just to protect my fragile self-esteem.

I can take a dish out of old stones (using loose SiC grit and solvent/oil) on a cast iron flat. Yes. But it is invariably replaced with a dome job. And, after about 10 mintues of lapping, I'm bored.

If I start with a convex plane blade or sole, forget it.

What do you use for grit and lap for your stones, David? Why can you do it so easily and I can't?

What did you mean by: "...I prefer using the appropriate grit for the final surfacing."

It's possible I need to make myself learn how to lap a convex surface flat...but I just hate the idea of returning to such a frustrating and seemingly futile activity.

As an aside *PICS*

woodburnbob


>I am gaining some ground on rigging up a Rube Goldberg arrangement to take the hump/convexity off of plane blade backs. I bought a box of old blades from Ebay a couple years ago and I'm still working on them.

I think you can see that the general problem I'm occupied with these days is cooking up non-hand-lapping methods to remove hard lumps and convexities from surfaces that need to become flat.

And, no, I'm not going to buy a surface grinder...yet.

This is a nifty little Gorton 265 single point grinder I got cheap for another purpose. You can see a plane blade mounted in a collet.

Here's the holding assembly.



A close up showing the arrangement. The head that holds the assembly rotates across the grinding stone...which is a cup wheel.

Just a trial run to get a sense of whether anything explodes.

It will work I think. No big heat problem but some deflection.

I need to revise the collet holding arrangement to get better rigidity but most to have find adjustments in the one plane of rotation that the grinder doesn't allow for.

Re: Whetstones Flattening Machine?

Thom D


>What happens if you use the world famous on WC diamond lapping compound. One assumes the particles would not be as friable and you would get agressive cutting action longer, allowing you to maintain your focus. I am not happy with what happens to diamond stones when they are used to lap cuttting stones.

Have you hollowed both sides, if not, degrease and fill the hollow side with epoxy, and use the flat side, this time not letting it get so bad.

Re: Whetstones Flattening Machine?

Ernie Miller


>If they are real bad how about putting them on a belt sander get them colse and then hand lap them? I just picked up a nice 2X8 in a box for �25 when I bought that saw and buck bros gouges

Re: Whetstones Flattening Machine?

Philip McKinney


>My first job was with a company that quarried and milled sandstone tabletops for use in laboratories. We used a machine made by Ty-Sa-Man Machine Company in Knoxville TN that had a 76" diamond segmented head that was used to flatten milled slabs to the specified thickness and provide a final finished surface. A conveyor over a platen moved the slab under the head and provided a flat reference under the slab. To get to the point, the wear characteristics of the matrix holding the diamonds was critical to the performance of the machine. Too soft and your unused diamonds washed down the drain. Too hard and you got a poor finish or overloaded the head drive motor (150 HP). An unnamed diamond tooling manufacturer once brought a head to test on our machine. In about 15 minutes the amp gage spiked, we shut down, raised the head and found that diamonds equal to the value of a new compact car at the time hand been flushed. For a one off this might not be a factor but over time you could lose a lot diamonds and effect the economic efficiency of the operation. That said, I use a beltsander and hand lapping on old stones. The belt will load quickly but the swarf can be removed by a water hose ( w/ the belt off the machine of course). I use kerosene a lubricant when hand lapping.

Using technology from other crafts

Bob Hackett


>As David mentioned used lapidary equipment could greatly cut the cost as compared to building from scratch.

Another simple machine that seems to be custom made for this kind of task would be a potter`s wheel.All that would be required would be to make a platten,charge it with grit and "Bob`s your uncle".I would suppose the purists among us would opt for a kick wheel as opposed to an electron eating model.Either way it`s something I`d look at before I`d go to the trouble and expense of building something from the ground up.

BTW-I`m looking at this type of equipment(kick wheel) and a counterbalanced arm which holds my pneumatic grinders to allow me to continue my stone grinding/sculpting projects.My recent hand and arm problems brought that to a halt along with alot of other things.

Mainely,Bob.