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large grinding stone


ZIG

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I guess this would be the best place to ask This.

Ok, I Just recently recovered a large grinding stone. Its been laying against a tree and was laid over on the ground for many Years. Still has the square shaft thru it. A little.
This has been in my family for over a hundred Years. So its special to me. I got the call tonight to come get It.
My point is. It is 30"+ round. Had some slight damage on the grinding surface. Not horrible but enough. That I want to know what is the best way to true it up. Get It back to working order. I'm scared to just try anything to it.
What would be the best way to get it to a useable surface again. I know I should have pictures but don't yet. So is there some wheel dresser for a rock That big. Cause I Don't believe I can work It out by sharpening axe heads on it.
Any suggestions would be greatly Appreciated.
I've been hunting For it for Years And want to build a pedal stand For it and use in my shop. So I gotta make it nice again. I owe That to my grandaddys to keep it in good shape once I get it home and get it rolling again. Wish I could ask them how they did it. Guess it stayed squared up in their day. From use. But ain't turned in over fifty Years. Or more.
Thanks in advance for any help. I'll try to get pictures but Can't stand it. Wanna get it home. But grounds to sower to reach it with truck or backhoe.

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Find a piece of wood to perfectly fit the hole... drill a hole on center and drive a 1/4" steel pin into it... that gives you a center spindle. Next, cut a strip of steel a little bigger than your 1/4 by 1 or whatever would work just fine. Now comes the part you need to finesse... afix a rotozip or similar high speed tool to the bar via "some sort of clamping rig". Drill a hole in the other end to fit the center pin we installed. You can then use a carbide burr to cut a perfect circle half way through the stone's thickness. Remove the whole jig, flip the stone, and repeat the process on the other side. Stop cutting just as you are about to break through, and lightly tap the outter ring of stone you have created to break it loose. You now have an perfectly round stone. To dress the face, mount the wheel on whatever drive mechanism you plan to use and use a rough rasp to dress it. I'd imagine a large dressing wheel would work as well, but you usually don't want to spin these big stones very fast, especially one that old that has been hanging around as you said. Usually it was a treadle rig that they used to spin them. The rasp is alot more agressive than a dressing wheel would be, so I would imagine it would work better.

I know of a guy who cuts new stones using this method from old sandstone sidewalk slabs.

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I would take a little less aggressive approach. I am in the process of restoring one now, to use at pre-1840's demos. I am building my frame, axle, treadle linkage & seat. Then plan to spin the wheel, as if using it, and dress with an angle grinder with a hard wheel. Here is a pick of one I'm patterning after.
post-8483-0-39743900-1296465350_thumb.jp

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Great ideas. Both of them are. Please keep them coming. Such a great bunch of people on here. Get responses That soon after midnight on Sunday. Gotta love that.
I think. It Got hit while someone was bushogging. But still in okay shape. It dates back to 1860s. So Lucky to have It. Gonna build same stand like picture. Please tell me more. I enjoy all.yalls input. Can't have to much. May have to holler at you on were you got some of your treadle parts. Gonna have to.be stout set up.to hold this bugger. Its a nice one. Can't wait to start.
Thanks, see how many more ideas I can get.

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I don't know it for a fact but I am personally confident that they used other stones to dress with. Even some of the same stone would work but as the sandstone was fairly soft it would be easy to get a harder stone for use as a dressing stone. A broken stone will often have a rough face and fairly straight edge that would work well. You can buy diamond dressers but the old guys would not have wasted money that way even had they been available then. A good diamond surface grinder for a 4 1/2" grinder would work too but at $80 to $140 I'd opt for the old way unless I was in a real hurry. A small hardened steel point set in a wooden handle is a fair tool for this too. By keeping your cutter thin it digs into the stone better and you just run it across like a lathe turning tool. As one edge gets totally dulled the opposite edge is sharpened... so just flip it until you run out of steel. Take fine cuts to finish with as the hogging cuts will be less accurate due to the wearing of the dressing tool.

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Note that with that much age on it, it may have "soft spots" from storing it where part could remain damp so even dressing it may not last "long.

Note too; old natural stones are NOT made for modern speeds; don't hook it up to a motor and end up killing someone when it blows up! (severe speed reduction down to "pedal" speeds is of course generally ok)

As for dressing: get a carbide tipped metal lathe bit and mount it on/in a long pipe handle and with the wheel spinning at normal speeds dress it to suit yourself---helps to have a tool rest to brace the tool against at the correct spot on the wheel!

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What also works is after you have it mounted in your frame build a u shaped jig that clamps onto the treadle stand,drill two holes on either side so you can put two pins through.Put rubber bands or bungie cords to give constent pressure and pedal away!!This was how i was told how to do it by an older gentleman at our museum.However your legs may hate you :D

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To get it round you will need to have the dresser rigidly mounted, if it is allowed to go in, and out you will have a dressed oval, or whatever shape it is now.

This can be done several ways, but an easy one would be to have a cross piece on the framework that you can hook the dresser over, and slide back and forth on. Have the dresser mounted to a piece that has an adjustable rest, or adjust the crosspiece in more when it has removed what it can at that setting. As the high spots are removed, just adjust it in more till it is hitting all around.

Dressers can be made of hard steel, carbide, diamond (not that expensive nowadays from the big machine shop suppliers), or other hard abrasive dressing sticks.

The main thing is restricting the depth of cut, and not allowing it to follow the original out of round surface.

When you get going, show us the pics.

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Thank y'all so much For the great advise. I like the various ideas. I want be drumming It over pedal power. When I can get it home I'll build my stand and fix a tool rest. So I can figure out how to use yalls ideas.
Appreciate all your input on this.

I'll post up pictures of my great grandaddys shop with anvil, hammer,stone,post drill. I've now have them in.mine. minus the stone just yet.
The picture is from 1906 and I hope y'all might enjoy it once I get It on here.

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If any of y'all have some pictures of some grinding stones with the treadle stand. Please post them For me. I'm gonna have To build a stand anyway and need some ideas or info y'all could give me.

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Zig, The old pedal stones I have seen being used are not always round. The speed is so slow your hand just follows the stone in-out or up-down depending on how you hold your part, maybe as much as 1/2" of runout or so. It is hard to remember, been a while since seeing one in action.
Rob

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Zig, The old pedal stones I have seen being used are not always round. The speed is so slow your hand just follows the stone in-out or up-down depending on how you hold your part, maybe as much as 1/2" of runout or so. It is hard to remember, been a while since seeing one in action.
Rob


Definately the case with old stones which were normally cut by hand, but if you have the option wouldn't you rather have true round?
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This whole thread has reminded me that I have been wanting to make a treadle stone for a few years now. Guess I should start calling the various cities around here and see if anyone is removing some old sandstone sidwalks that I might be able to salvage. The frames are fairly easy to build, and the mechanics are just mounting the thing on a spindle with an offset to attach to the treadle linkage. Another thing to remember about these beasts is though the RPM is nowhere near what modern bench grinders do, because of the tremendous circumference of the stones, the surface speed does approach the surface speed of the smaller grinders. Always good to remember that though the stone isn't turning as fast, they can still abrade away a layer of skin in a right hurry.

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.... don't forget that old stones need water for cooling and cutting effeciency... I have used the scrap from leaf springs to true up my stone. ... they do tend to get a little cupped in the middle if you are not careful with you grinding... and they will take off skin if you are careless....

good luck
cliff

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If you are just looking to bring your wheel back to a usable shape, rembering that it will not look like a modern cut circle, a piece of quartz covered stone will work. The quartz is hard enough to wear down the grindstone (or rough in your rounded over cold chisle) and if it is a thin covering on sandstone the quartz will chip away should you become too aggressive without any major grindstone damage. Just get two blocks of wood and (using two bolts) make a clamp/handle. Is slow but works great.

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Any old grind stone that I have ever seen was out of round, mine was about 3/4'' out of round. I wore out a few old rasps, some carbide saw teeth, and some leif springs, it was still out of round I used it anyway. One day a good friend of mine was showing me his treadle grinder and how perfectly round it was. He had his wife peddle it while he used a hand held wood router with a square end carbide bit to carefully machine the face of the stone. I said that I had a grind stone that was really out of round but would never treat a router that way. He thought I meant I did not have a router, so he said, well use mine if you want, just clean it up when your done because I am going to give to my brother for Christmas. I used it to true up the face of my grind stone blew it clean with compressed air and gave it back to him. A few weeks latter he was in my shop looking at my now round grind stone when he saw my router and said. You son of a bitch I thought you said you didn't have a router! I looked him and said. I never said I didn't have a router I said I would never treat a router that way, thats why I used yours. Were still good friends and his brother never knew the difference.

I went slow and wore a full face shield and respirator, if I had any extras I would have let my wife wear some to.


Chuck




I guess this would be the best place to ask This.

Ok, I Just recently recovered a large grinding stone. Its been laying against a tree and was laid over on the ground for many Years. Still has the square shaft thru it. A little.
This has been in my family for over a hundred Years. So its special to me. I got the call tonight to come get It.
My point is. It is 30"+ round. Had some slight damage on the grinding surface. Not horrible but enough. That I want to know what is the best way to true it up. Get It back to working order. I'm scared to just try anything to it.
What would be the best way to get it to a useable surface again. I know I should have pictures but don't yet. So is there some wheel dresser for a rock That big. Cause I Don't believe I can work It out by sharpening axe heads on it.
Any suggestions would be greatly Appreciated.
I've been hunting For it for Years And want to build a pedal stand For it and use in my shop. So I gotta make it nice again. I owe That to my grandaddys to keep it in good shape once I get it home and get it rolling again. Wish I could ask them how they did it. Guess it stayed squared up in their day. From use. But ain't turned in over fifty Years. Or more.
Thanks in advance for any help. I'll try to get pictures but Can't stand it. Wanna get it home. But grounds to sower to reach it with truck or backhoe.
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That's pretty funny Chuck.
I'm like you on That. I wouldn't wanna do that To mine either. I'm not so concerned about a little outta round. I Can't get it picked up to see it All. So hope it ain't got hunks outta it.
I'll know more once ground gets fit to get to it with a backhoe. Just wanna get it decent. To use. But make it look good too.
But with the weather we've Had it'll be awhile before I can get It. I can't flip it by hand.
Also bought a 6 inch post vice on a welding table. But Can't get it cause we've had rotten weather And the ground is so bad shape. And its to graveyard to tote. Wanna get my shop straightened up. Since duck season is over with. And get theses decoys off my tables And return my shop back to what its supposed to be used for.
I like to have things arranged but had to park truck And boat together in there. So had to shove a few things up against the wall.
Y'all have been so nice with your help. Wish I could tell you more. But I'll post pictures as soon as get it home.
But would love to see the ones y'all got. Just to give me some good ideas on his to build my treadle. I know how and what I.want. but always like To see others work. Saw a nice one other day. But stone is only 12" it had a square wooden shaft in it. But the made it into a hand crank. No good for me.
Hope the weather Ain't wearing y'all out. Be careful and stay safe. Its getting rough on.some of y'all. Stay Warm. If You can.

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Good luck when you dig it out.
One thing I forgot to say, don't put one of those troughs half full of water that the stone runs in, it will sling water all over the place and on you. Not fun in cold weather.
Any stone has a heavy side that will stop heavy side down in the trough when your not using it, it then soaks more water making it heaver and that will cause it to wear out of round faster. Also the dryer side wears a little faster. I like something that hangs over the top of the stone that has a small valve that can be adjusted to drip. You don't need that much water to keep the steel cool.
I also like my Wilton belt grinder better yet.
Chuck

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I'd have to dig, but there was a book of recipes at the school library years ago, it had a recipe for making a resin compound of some sort to build up the soft spots til the rest of the wheel wore down even. uhmmm...was something like 2000 recipes from the late 1800's early 1900's. I had photo copied sections, not really sure where it all got to. That recipe stuck out a little for Gr. Grandpas pedal powered wheel.
His blower was home made, a converted milk separator, with a tin cage and fins.

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