Homebuild Treadle grinder questions

[james austin]

Hi All,

I've been thinking for a while about building a treadle grinder for myself.  I really like the look of the old sandstone treadle wheels but I've read that they are quite slow grinding due to fine grit.  I've not been able to find any large new wheels, and the antique beasts have often been sitting in a garden for a decade or so, and don't really look like much fun to true up. 

I've found a couple of versions with wooden wheels that seem to work reasonably well, so I thought about it for a while and sketched up some plans. 

I'm planning the wheel to be laminated from MDF board 4" thick, with a 24" diam.  I think this works out to be about 40-50 lbs.  The drawing above calls for an axle (or spindle?) from 3/4 inch black pipe, but I realized after the fact that they don't make bearings to fit, and I don't have any way to turn down the OD to fit existing bearings.  I was thinking that 5/8ths 1045 turned and ground stock would make a good alternative, and I can get bearings to fit.  I'm planning on using pillow blocks for the bearings to limit the amount of precision drilling required.  I'll be using either adhesive backed grinder belts, or plain ones with double sided tape for the abrasive.

I wanted to check on a couple of things before I start ordering materials.  First is there a better wood material to build the wheel from.  I'd picked MDF due to what I thought was a higher density than real wood, but perhaps there would be a better material (i.e. heavier).  Secondly I wanted to make sure that 5/8" 1045 will be strong enough for the spindle, which will also need to double as the crankshaft.  Or maybe 5/8 is overkill? 

Apologies if these are obvious questions, but I don't really have a good handle on materials specs for things like this.

Sources

https://www.youtube.com/watch?v=F06VMPmzZCg

https://www.youtube.com/watch?v=cDeoCNRuKOk

 

[ThomasPowers]

Remember the foot treadle ones are NOT for grinding; they are for light touch up of edges/surfaces.  You would remove more metal faster hot rasping a piece!

[james austin]

That's good to know Thomas.  I was under the impression that they could be used for a bit of both. 

I am planning a bit more than just touch ups, but not really extensive grinding.  Thinking of analogous power tools, I was thinking more of a Tormek than a belt grinder.  I was hoping that the larger diameter would give more surface speed, and work a bit faster, but mostly I'm interested in using grinding jigs like the tormek, and wolverine fixtures.

[anvil]

You need the heavy mass of a grinding stone. Speed is less important. It doesn't take much "push" to bog down a light weight wheel when you have a pedal machine.

[ThomasPowers]

For heavy grinding, large stones were used.  You can still see some of the "worn out" 4' diameter stones used to grind anvil faces in the river below the old anvil manufacturer in Columbus OH.  When they wore down they were rolled into the river.

[Ohio]

On February 26, 2020 at 7:00 PM, james austin said:

I wanted to check on a couple of things before I start ordering materials.  First is there a better wood material to build the wheel from. 

Okay, I get what you're going for here---light touch-ups of cutting edges, definitely not for re-grind. Looks fun.

I don't like working with MDF (personal preference, not a comment on your character---I'll wait till I know you better to do that) but it is heavy and strong. And expensive. 

I was wondering if you could use pre-existing wood shapes. For example, big stores sell 3/4"x4'x8' MDF for about $35 around here. They also sell round pine table tops or plywood birch circles for about $12 each (you might even find free ones on CL). Perhaps you could glue-up four or five of those table tops (alternating grain direction for any solid wood), then route and drill to fit. You may even be able to add weight between layers of the glue-up by insetting steel, though you'd need to be careful about balance.

You could then sand or circle cut the perimeter or fill any gaps with something like Bondo. Might even then glue a hook-and-loop to make changing grits easier.

I'd also suggest having a shelf on which to rest your arms as you touch up edges and in case the workpiece slips or some piece goes flying---it may stop you from getting hit in a sensitive area.

Be interesting to see how you proceed.

[ThomasPowers]

IIRC one of my old smithing books mentioned making your own polishing wheels by using corundum grit embeded in shellac.  Might have been "Practical Blacksmithing"... this was done over a wooden wheel IIRC.

[Irondragon Forge ClayWorks]

I have a couple of wheels where the grit is embedded in Elmer's glue over fiber board. They didn't work very well if I recall they are the Jantz JS801 system.

[ThomasPowers]

Modern abrasives and electric motor powered grinders hve made a big difference in knifemaking; though there are still folks doing it all by hand; some even with natural stones.

[Irondragon Forge ClayWorks]

I have a big sandstone 2 inch by 26 inch (I think) wet grinder that is powered (converted from treadle) and it does an excellent job of finishing knives and other cutting instruments.

I once toyed with the idea of converting one of my wife's spinning wheels into a grinder. She in so many words, told me not to sleep if I messed with them.

[Frosty]

Mass is important, very. Dia of the wheel is as important. Wood wheel with grit glued on might work but . . . 

This is an easy problem though and might make the stone wheels a curiosity even for treadle wheels.

Here's my thought. You can buy 2" x 72" belts in a wild range of grits. How about just making a heavy wheel one will slip onto for your treadle. By heavy I could torch cut a piece of 1/4" - 1/2" steel plate and weld on a 2" band. The axle could bolt to it like an automobile wheel or similar and connect to the crank and treadle on the far side of the stand through double pillow blocks. This will leave one side of the wheel exposed so you can slip belts off and on at will. 

Another less attractive to me wheel could be cast from concrete and mounted as described above. 

The wheel diameters would need to be approx 22.92".

Hmmm?

Frosty The Lucky.

[ThomasPowers]

Ahh yes the old "quietly and violently in your sleep" line.  I've heard it a couple of times...

And for folks thinking about this: WATCH THE RPMS!  Sandstone wheels were run at MUCH lower rpms than modern abrasive wheels and spinning them past their cohesive rate produces a fragmentation grenade often aligned on YOU the user!

Frosty, what about huge conelock wheels for abrasive strips?

[Frosty]

Cone locks would hold them nicely. Locking a belt on was something I was leaving for later brainstorming. I thought about buying belt by the roll and gluing it to the wheel but didn't mention it for a couple reasons, mostly the cost of having a variety of grits.

Frosty The Lucky.

[james austin]

Hey thanks for all the ideas folks!

Frosty: making the wheel to fit a 2x72 belt was my first idea, I decided I wanted as much weight as possible, but a 2’ OD wheel seemed like a better use of 4x8 sheet goods. I think a steel wheel would be great for weight, but I haven’t got access to the cutting, bending and welding equipment.  I can borrow pretty much any woodworking tools from my dad.

i like the idea of mounting the axle on one side of the wheel, but I don’t know how strong an axle is needed for that.  Seems like it would be easy to bend.  What size axle would you recommend?

All the comments on weight make me wonder if I should increase he size.  Going to a 3’ wheel would get me up around 75 lbs.  4’ would still come out of two sheets of MDF.  Still not sure of a shaft size for any of these though. 

I’ve gone back and forth between using existing belts, and stick on rolls.  Belts would be easier to get in variety, but need an open side on tv e wheel for install/removal. Rolls would be easier to apply, but are expensive, and I haven’t found nearly the variety of types, particularly ceramic abrasives.

All I get for cone lock wheel is a type of nut.  Are there premade wheels they go to? Looks like a good way to attach the wheel to the shaft in any case.  I was thinking of using some sort of collar & set screw to secure the wheel

[Charles R. Stevens]

If memory serves some one on here build a 2’ diameter wheel with a drive to simulate the curve of a large stone with 2” grinder belts.  The basic idea was an electric drive wheel spinning the belt on the large idler.  I don’t see why a 12-18 speed bike gear set wouldn’t work.

[ThomasPowers]

Now before you go to all this trouble and expense---have you worked with an original one to see if it actually does what you want it to do?

Wish you were closer; I have 3 or 4 original ones out front of my shop that were part of the hoard and I need to sell on...probably as lawn ornaments...

[Frosty]

If you made a 2" x 22" wheel from solid steel it'd only weigh about 275 rounded. How much shaft do you think it'd take to hold 275" on a close pillow block, 1/2" rnd? A section of 1" would hold a 4" disk easily and you could use 4" belts. 

The weights you're talking about are not going to bend the axle, just don't go silly small, the 1/2" dia. I mentioned above was silly small. Yes?

If you want heavier, make it thicker, you can find wide belts more easily than odd diameter ones. Heck, put two 2" belts on side by side Hmmm?

We're not talking a high stress piece of machinery here, I wouldn't bother to key it to the shaft, I'd use nuts and washers from both sides if it slips, thread lock will stick it to the shaft. 

Frosty The Lucky.

[james austin]

Charles, I think that grinder is also one of the inspirations for this machine. I’ve thought about using bike gears for this but it adds a lot of complexity to the build.  I may still though.  I’ve got all the parts lying around.

I haven’t had the opportunity to try an original stone Thomas. I spent most of the fall on Craigslist and the local flea markets but not been able to find one in decent shape yet. I am hoping to be able to build this do about the 75-100$ that one of the stone wheels seem to go for. 
 

I spent some time yesterday figuring possible weights for different diameters.  Frosty got me thinking about existing belt sizes too. Looks like a 42” wheel should just about fit a 3x132 belt, which seem at least somewhat common and could still use shop roll.  Looks like it would weigh in around 115lbs. 

18 hours ago, Frosty said:

just don't go silly small, the 1/2" dia. I mentioned above was silly small. Yes?

This is one of my big gaps here, I don’t really have a sense of what is silly small,  would 3/4” sound more reasonable? 1” to be safe?

thanks again for the help everyone!  

[Frosty]

Yes, 3/4" is good 1" better. Just keep the bearing close to the wheel and you're golden. You'll need 2 pillow blocks and that'll push your budget. The frame is simple enough but needs to be reasonably stable and why the seat is so often part of the frame. 

If you wanted to go old school you could make bearings like the mains in an engine but from wood with a hole saw and gristle, lubed with lard but it'd attract the neighborhood: dogs, cats and birds. Of course the "My treadle wheel grinder got eaten by ravens," would be one heck of a story. 

How good are you at scrounging at the auto wrecking yard? Bet you could find an axle and bearings you could make work for not horribly much. Hmmm, a space saver spare filled with cement grout with grinding belts would be a good post apocalypse build. 

Okay, that's a bit out there sorry for the Frosty drift, I hear thoughts and see things. It's the voices, the voices I say! 

Frosty The Lucky.

[Irondragon Forge ClayWorks]

That compact spare is really a good idea. Using it as is, let the air out to change belts then inflate it to hold them tight.

[Frosty]

Finding the right size belts is still the challenge. Using tire pressure to change belts makes for a lighter wheel by about 150 lbs./cu/ft. 

When I said gristle for the bearings I'd blanked on the term I meant "bacon rind." Dad and his brothers used to tell a story about having to use bacon rind for main bearings in a Model T during the depression. 

Frosty The Lucky.

[james austin]

Bacon for bearing lube.  Man I can only imagine the smell around town on a Sunday after church!

i have been meaning to start checking the salvage yards anyway looking for some springs, so I’ll add axles to my list. and start reading up on wheel bearing assembly...  

Filling a tire with cement really does seem like a good idea in a lot of ways.  Lots of weight, all way out at the edge of the wheel, prefab mounting system.  You’d need to make some kind of mount for the end of the shaft, but I suppose you could take the whole rear wheel/axle assembly, though maybe there’s more involved there that I think.  
 

[Frosty]

If you can run a treadle wheel fast enough to make bacon rind smell like breakfast I want to see the video!

Naw, not a whole axle, just enough to reach through the frame to your crank arm. I'm thinking a front wheel drive. All you need is the last bit before the wheel. Weld it to the frame and the axle can be held by most anything it's not supporting any weight. Heck, connect the crank arm to the constant velocity unit the double U joint looking thing.

Of course there's more involved when you're improvising from salvaged components or just building your own. As simple as it is and having plans in hand I had to do some tweaking to get my 2" x 72" grinder to work properly and I need to make a couple changes to get it right. Works though so unless I have to I'm calling it good. 

Okay, here's  another improvisation for you. Build it from a bicycle. No chains, gears, wheels, etc. just the frame and pedal crank shaft, arms and bearings. You're only talking what 75 lbs or so? So strip a bike to the frame. pull the pedal from one side and the crank arm from the other. Weld it with the crank on top to a base of your liking. Mount your wheel to the crank shaft without the crank arm. Attach our treadle linkage to the crank arm on the other side. Hook up your treadle sit down and get to being abrasive. 

Will it be strong enough? Depending on how well it's built plenty, I never had an issue standing on my pedals and yes, I put my whole 200 lbs. on them one at a time.

Hmmm?

Frosty The Lucky.

[james austin]

poking around tonight and found an old Popular Science Monthly article on casting a cement flywheel to use in building an “amateur lathe or any other foot-power machine”.  
oct 1919

i really love old magazines!  

[Fowllife]

MDF would be pretty far down the list of materials I would try to use for this, at least here in Ohio. With our crazy temperature swings and high humidity I don't know how long MDF will hold up. Any cut joint will absorb moisture unless sanded and sealed extremely well. I really don't like using it in basements (will use MDO instead) and I would not use it for anything outside.