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Homebuild Treadle grinder questions


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It seems you have some definite ideas about the treadle grinder you're planning on building.  I had also toyed with the idea of casting a concrete/square holed grinding wheel but never got much past the design phase.

The design attached has been sitting in my 'projects to do' folder for a long while now, but might help a bit in your design process.

bike grinder.JPG

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That is an awesome grinder Michael!  I thought for a while about something like that.  even went so far as to buy an arbor to run wheels on, but I never quite sorted out the mechanism to treadle it.  I like this because you don't even need to modify the wheel just mount it to a frame.  Is the chain return just a bungee cord?

Fowllife: I chose MDF only for its weight and route-ability.  So far I haven't been able to find anything that is as heavy, and as easily workable as MDF.  I think there may be a good argument for casting it in cement or similar, but I'm not as confident in my ability to cast a true and balanced wheel. 

I had been wondering about sealing the wheel somehow, but figured I would get to that when I had the thing glued up. Guess I should give that some more thought as I am collecting materials.  Thanks for the tip!

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Heh, heh, heh, lots of potential in old bicycles. Consider a little more elaborate frame holding a couple more similar size bike wheels, each one's sprocket replaced with a small diameter rubber or heck hand turned wooden wheel rolling on the preceding tire. Let's see where that goes. . . A 26" bike tire to a 4" dia. wheel, (Sprocket replacement) is 6.5 : 1 so for every revolution of the first wheel means the next one turns six and a half revolutions and if we do that again the third tire is turning 42.25 revolutions for every revolution of the crank.  

Old bicycles are such useful resource to have around. 

Frosty The Lucky.

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Ha!  Frosty your taking me back to middle school!  I can still remember a whole unit on gear ratios, and the workings of a mill, which ended with a field trip to Slater Mill here in Rhode Island.  I spent probably a month solving gear ratio and transmission problems.  Still remember that as one of the best science projects I've ever done. 

Also I finally found some time to look up Practical Blacksmithing which Thomas gave earlier in the thread, and there is indeed a whole chapter in Volume II dealing with making "emory wheels".  There are some interesting ideas or gluing abrasive to wooden wheels using a variety of substances, as well as some good info on hanging wheels as well.  Thanks for the recommendation Thomas!  I can tell I've got some time to spend with that series.

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"Practical Blacksmithing", Richardson, is a classic resource for late 19th century small shop smithing!   However for folks NOT trying to replicate pre-1900 shops; well there have been a lot of advances since then.  Electric motors and modern abrasives, arc welding as a common thing---lots of real labour saving devices!  (Since I do Y1K sometimes I can read PB as Far Future Fantasy of smithing and dream of it while I'm telling the apprentice to pump the small single action bellows faster!)

Having done stuff "Old School" I can sure appreciate modern times.  (Of course without modern medicine I would have died around 35 years ago, if not several times before then.) Though I really shouldn't be talking against PB after spending some of my lunch time finding out where local iron ore deposits are to hopefully run another bloomery this spring/summer.  (There's a hematite deposit that's dang near in town!)

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On 3/4/2020 at 9:31 AM, james austin said:

That is an awesome grinder Michael!   Is the chain return just a bungee cord?

I think so, and a freewheel sprocket from a bike so it only engages the gear on a downstroke.  I think hardest part would be a arbor the grinding wheel rides on and the tire presses against.  Again, I never got around to building this, the scrounging gene in an urban area meant powered grinders found me before this got built. 

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If you go with the freewheel sprocket you'll need a return spring to return the chain for the next stroke. However having a live treadle is a good thing, you get used to them in seconds and good with them in a few minutes. 

I don't understand the problem with an arbor for the grinding wheel. I've never met one in America that wasn't a standard bolt size.

Frosty The Lucky.

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  • 6 months later...

Hey yall,  been a while since I've had any time to even think about building anything, but lately things have eased up a bit at work, and I've had some time back to myself.  I thought I'd post a bit of an update on this project, and I have a more questions, which I will leave at the end.

Spent the last weekend trying to build some of this out, and have the basic frame together now.  I ended up putting the big wheel grinder on hold for now, and instead worked up a version of the grinder Michael posted up thread. I'm planning to put the treadle together this weekend.

The structure is just some 2x that was left over from something, and the grinder came from a local tool consignment shop.  Rather than run the spindle by friction on the tire, I am planning on just running a round belt on the bare rim  up to the pulley on the arbor. 

I spent some time today cleaning up the arbor, and flanges, and what I thought were bearings, but on removing the arbor it appears that maybe they are bushings?  They don't move at all, and the little oil or grease port at the top goes straight through.

 

Did these types of grinders use bushings?  In any case what would be the correct way to lubricate this? do I need a grease gun? will just a squeeze tube work?

Hope folks are doing ok out there!

 

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Thanks Irondragon,  these really threw me off. I’m not sure I’ve ever seen oil ports like this, and just assumed grease and roller bearings.  

Oil sounds like it won’t be too hard to manage. Now to go read up on bushings! 

thanks again

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Scraped together enough time this week to get this thing working. Stone and drive belt came in Monday, but of course I ordered the wrong arbor size. Got a 5/8, when I needed a 1/2. Night the cheap wheel too so no adaptor bushings. 

image.thumb.jpeg.ef9097cc9ae4514bfb58069e70e2f7ed.jpeg
Found a spacer at the hardware store and just filed it down right on the arbor. No slop at all now, and the wheel runs nice and true. 
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Once that was finished I welded up the drive belt. And had to tear off the cross brace connecting the two sides to install the closed loop belt. I think I will need to add some sort of hinged brace on the short ends but I’m still thinking through that all. 

the belt was set pretty tight, so I had to wire the axle down.image.thumb.jpeg.9189ec69242edc52618aec938ef0717b.jpeg


the chain is just wired to a treadle arm.  I used a small spring instead of a bungee.

image.thumb.jpeg.fc4e05c2105581c7720498988e23234c.jpeg
 Frosty you were absolutely right about the live treadle. It is totally intuitive, and works great.

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There are still a few jobs to finish, but she spins fast enough to throw sparks while grinding. 

Thomas, I am planning on adding weight to the flywheel, although I was surprised at how much difference the grinding wheel made to the inertia. It gives me some hope it won’t take a huge amount of weight to keep the system going. 
At the moment my plan is to work a fat roll of clay/adobe up under the rim, and inside the spokes. I’m not sure it will hold though, so if anyone has suggestions I would love to hear them. 
 

im also planning on making a ~12”x2” disc out of MDF for the other side, which will add a bit more rotating mass. I’m still thinking of gluing on abrasive cloth and maybe a disc on the face. 

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If you try packing weight into the wheel you'll have to balance it or it'll get shaky. I was thinking of adding lead in the rim where your belt runs but I haven't seen the old wheel weights in a long strip in a long time. The service station where I work finally got a tire machine that could work on mags without scaring them up and a spin balancer. Can't use clip on wheel weight on mags so we started using glue on weights. The ones I liked best came in a roll, adhesive under the tape back and marks in increments on the other side. The spin balancer read out how much weight and where to put it, count increments and snip it off with end nippers. 

Sorry for the ramble but that roll of tire weight lead is the first thing I thought of when I saw your grinder. 

However, I think the mass would be more effective on the grinder mandrel so I'd rather just mount another wheel or similar. Torch a disk from 1/2" plate, drill a 1/2" hole and use the grinder itself to true it up. Maybe mount a disk grinder in a fixed but adjustable position so it'd grind high spots off the disk as I SLOWLY worked the treadle. Just keep moving the disk grinder in until the flywheel ran true. Balance it by drilling holes in the heavy side.

Hmmm?

Frosty The Lucky.

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Now you got me thinking of the split shot fishing weights on the spokes to balance it if it needs it.

Putting a counter weight on the other side of the mandrel would work well.  Or even a different grit wheel.

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Split shot would work a treat. It's the getting them where they need to be that's the trick. Maybe take the wheel off the stand and balance it to stand level on the axle laying on it's side. Like the old bubble balancers. Close should be good enough. 

Frosty The Lucky.

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Yeah, the truing and balancing is the thing I I worry about with adding weight. I wondered about tire weights, but honestly don’t know much about them, and just assumed they came individually. I’ll look around and see if the strips you mentioned are available cheaply online. 

I’ll definitely be adding a wheel to the other side, but can’t quite decide what it should be. The one I’ve got is a soft 100 grit alox wheel, so I think I want something more aggressive. 
 

and no worries about the ramble. Y’all rambling is one of my favorite parts of this forum. 
 

I’ll also look out for split shot lead. Balancing with the axle on end also sounds like a great trick no matter how I get weight added. 

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I've given using a bicycle to power things like blowers, and considered filling the tire with grout but was never sure how to get it evenly distributed. 

Split shot in the sporting goods section with fishing gear. They come in different weights.

Maybe hanging the wheel from the axle would work as well. Sure be easier if it worked.

Frosty The Lucky.

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Yeah filling the tire seems like an easy thing until it gets to the last bit. I was thinking clay around the inside of the rim. I figure I could run a fat coil around the rim, then spin the wheel and throw it like centering a pot on a wheel. It’s possible that this is one of those things that sound better in my head than it turns out to be. 
 

I think the next step will be to put a second wheel on there. That will add weight and give me a second grinding option. And it will give me some time to think about the flywheel. 

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How about lead shot and polyester resin? 

Nice grinders, all a boy needs is a line shop and it's a go.

I have a few I picked up at a yard sale some years ago and have wondered if they could be powered with a rubber drive wheel like a tire hammer.

Frosty The Lucky.

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