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About mid 2011 we dicided to make some changes and send my wife to school along with moving. I had to take a year off of work and sell many of my tools and machines to finance the adventure. One of the victims of the sales was my trusty BurrKing 2x72 which I had been using for nearly 20 years. The only way I could let it go was with the hope that I could build a better grinder for less money. Upgrades from 1 Hp single speed to Variable 2hp plus. Quick change tools would be nice too. My friend Ric Furrer Who was only a few hours away from my temporary home loaned me a Bader Space saver. It was an interesting machine and I liked some of the things about it including the 132" belts. I am still a fan of the 72" belts as the varieties of these on the shelves is like a candy store.

 

So I set to design (in my own convoluted way) a Grinder that suited my needs including my eccentricities. I built and tried out a dozen variations in my 3d drawing program, Rhino. I was mired in choices and could not decide which way to go with it. Well the build time is here and I could not wait any longer so I made some hard choices and dove in with mostly what I had on hand already. It is not intended as a "knife grinder" persay, I have some contact wheels on hand and will build the first attachment based on them and my immediate needs for platen in excess of 12 inches. Later though I will add other wheel attachments as the needs arise.

 

So over the last six months I have gathered

$220 in aluminum and steel stock from Speedy metals.

A free 3hp 3phase motor. Untested so far.

A $575 Variable frequency drive/phase converter rated for 3hp.

The wheels were not free, but they did not cost me anything yet either...

2, 4" diameter contact wheels with bearings.

1, 3inch drive/tracking wheel with keyed bore

1, 3inch idler/tracking wheel with bearings.

One big bag of 2"x132" belts some new some used.

I purchased 100 1/4" x 1" Torx head cap screws and a new tap from McmasterCarr. $26

 

I said I would take you along with my grinder build so here is how it has progressed the first weeks worth of labor.

Grinder build pics

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That looks great.

People are going to want the plans for sure.

I look forward to seeing the finished machine in photo and video.

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So far so good. I would love to have a 72", and might try and modify the little 42"(?) that I have in my basement.

Even so early on, the precision of the fit between pieces is very clean. I'm sure it will be a great machine!

 

John

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So far so good. I would love to have a 72", and might try and modify the little 42"(?) that I have in my basement.

Even so early on, the precision of the fit between pieces is very clean. I'm sure it will be a great machine!

 

John

 

I tried to engineer as much precision work out of it as possible. Lots of raw squareish cut pieces utilizing the relatively straight factory edges for intersections. The quick change bar glides in and out like its on ball bearings. I just clamped it all together nice and tight and drilled and tapped with everything in place. I drove the bar out with a mallet and wood stick. ran the file over it lightly on all four sizes and now its a smooth precision fit. It is a good basic concept that is less expensive than steel. However the long tension system is a real pita and I had to make many absolutely precise sized and located holes for that. A 72" inch however would not need that at all.

I worked on the motor to wheel adapter today and the motor face plate. I hope to have the motor mounts and tracking done this weekend.

DSC00173.JPG

Patrick B)

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just wanted to chip in ... i see a lot of people on different forum talking about the wheels being expensive...

Out of curiosity.... could one use the wheels used on palletjacks? .. theire meant for heavy duty, have steel roller bearings, and looks pretty tough....??

- i undertand the largest contact wheel might have to be a real one, but for the smaller ones..?

dn-51728-2011.jpg - - like that one ?

 

-vidar

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just wanted to chip in ... i see a lot of people on different forum talking about the wheels being expensive...

Out of curiosity.... could one use the wheels used on palletjacks? .. theire meant for heavy duty, have steel roller bearings, and looks pretty tough....??

- i undertand the largest contact wheel might have to be a real one, but for the smaller ones..?

dn-51728-2011.jpg - - like that one ?

 

-vidar

 

 

That type of wheel is NOT designed for "High Speed" even though it has a roller Bearing in it ! It IS for "Weight" (not speed)! and would get you hurt fast. the side rings you see on the wheel are thin shims that are to center the wheel in the pallet jack wheel area and are meant to wear out like a thrust bearing and would cause issues the rubber also is not bonded for speed but for weight . IE spun at high speed it will fly off.

 

Sam

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That type of wheel is NOT designed for "High Speed" even though it has a roller Bearing in it ! It IS for "Weight" (not speed)! and would get you hurt fast. the side rings you see on the wheel are thin shims that are to center the wheel in the pallet jack wheel area and are meant to wear out like a thrust bearing and would cause issues the rubber also is not bonded for speed but for weight . IE spun at high speed it will fly off.

 

Sam

 

darn... back to the drawing board....

Not that im opposed to quality over price.. but doesent anyone know of a source for these wheels that arent THAT expensive?...

 

-vidar-

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Would it work if you swaped over the actual bearings in the pallet wheel? As teh wheel should be able to cope with high speed?

Andrew

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Would it work if you swaped over the actual bearings in the pallet wheel? As teh wheel should be able to cope with high speed?

Andrew

 

If you have to go in and start changing bearings It may not be worth the trouble anymore. Lots of people out there using salvages wheels. Just be careful in the testing stages not to stand in the wrong place and watch for evidence of failure. Try doing a Youtube search for knife grinders and you will see the variety of re purposed wheels.

Rubber contact wheels can get really pricey it is true, but SunraySells wheel for about half the prices you usually encounter and you can pick your color and hardness bore and such in a huge variety of sizes. They are urethane treads, but Urethane is great stuff. There is a passing concern with the lower melting temp, but I have yet to hear of anyone getting them hot enough on their grinder to be a problem.

Patrick B)

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they have the wheels you need and a few other things it is a PDF and a lil big it will take a lil time to up load for you a min or so .

 

http://www.sheffieldsupply.com/catalog/SupplyCat.pdf be safe !

 

Sam

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If you have to go in and start changing bearings It may not be worth the trouble anymore. Lots of people out there using salvages wheels. Just be careful in the testing stages not to stand in the wrong place and watch for evidence of failure. Try doing a Youtube search for knife grinders and you will see the variety of re purposed wheels.

Rubber contact wheels can get really pricey it is true, but SunraySells wheel for about half the prices you usually encounter and you can pick your color and hardness bore and such in a huge variety of sizes. They are urethane treads, but Urethane is great stuff. There is a passing concern with the lower melting temp, but I have yet to hear of anyone getting them hot enough on their grinder to be a problem.

Patrick B)

 

hmm.. sunray has pretty decent prices... might very well get from them later on.... i DO notice theres ppl on ebay selling aluminium contact wheels ..

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200831766223&ssPageName=ADME:X:AAQ:US:1123

... but thats mostly for europeans i guess....

 

-vidar-

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Looking good Patrick. Aluminum contact wheels are dangerous. You will burn through your belt and it could smack you repeatedly in the face. I'm sure that would feel good with a 36 grit:blink:

 

I prefer the rubber wheels over the urethane, but the rubber ones are pricey.

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Looking good Patrick. Aluminum contact wheels are dangerous. You will burn through your belt and it could smack you repeatedly in the face. I'm sure that would feel good with a 36 grit:blink:

 

I prefer the rubber wheels over the urethane, but the rubber ones are pricey.

Rubber is king for the most part.

Those aluminum wheels on ebay are not meant as contact wheels (I hope) They would be best used like this setup being sold by Beaumont Metal Worksbdr-pla3.jpg Yet another source for high quality rubber contact wheels.

Patrick B)

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yep usually the aluminum wheels are meant as idlers, or tracking wheels

 

Nice looking platten attachment

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hmm... maybe i should just get my brother to make some wheels on the metal "carving" machine he has at work... can make wheels out of a thick roundbar, down to 1/xxx mm .... theyve used to make conveyorbelt rollers a while back.... .. then precision dril out holes and squeeze SKF ballbearings into it... would that work ?

 

or failing that.. would something like this work ?

 

82-334_l.jpg

 

 

I also found THIS wheel on a store that sells parts for extreme motorsports...

chainroller.jpg

-vidar-

Edited by vihalvor

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That (having your brother make them) would work for idlers and drive wheels, but the contact wheel surface really needs to be coated with some sort of rubber at a hardness of about 80 to 90 durometer on the Shore A scale. Any decent lathe can do idlers and drive wheels, keeping in mind they require a slight crown for good tracking. The center of the wheels should be about 1.5mm higher than the edges, in other words. Contact wheels are flat, but can have radiused edges.

 

The wheel you posted may or may not be a good choice for contact wheels, it depends on the hardness and "give" of the rubber.

Edited by Alan Longmire

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hmm... maybe i should just get my brother to make some wheels on the metal "carving" machine he has at work... can make wheels out of a thick roundbar, down to 1/xxx mm .... theyve used to make conveyorbelt rollers a while back.... .. then precision dril out holes and squeeze SKF ballbearings into it... would that work ?

 

-vidar-

 

To get balanced wheels you really need to use a lathe and do the bore and outside of the wheel in one setup. Then they are perfectly concentric and will be balanced at speed. You still don't want to use them as contact wheels, but as drive wheels, idler, tracking wheels it is fine. Tracking wheels usually have a crown or double bevel surface. They do not work as effectively with flat faces.

Put a little research into it before wasting $100 in shop time trying to save $20 bucks.

 

 

Patrick B)

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Looks like we're all posting and editing at the same time! :lol:

 

Vidar, that last wheel you posted might do as a light-duty small contact wheel (5cm and smaller), but larger ones are solid so the rubber can't creep under pressure.

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heh. yeah ... thanks for the feedback, guys :)

im definately not one that settles for the best retail price out there, but im also not one of those that saves myself poor :P

i just believe in doing very thorough research before buying :) .. in general, i find that buying at specialist retail stores usually comes at a very high premium, where the same product, given a few days research, can often be found elsewhere at far lower cost... :rolleyes:

That is why i jumped in passionately into this tread.. if WE can find options for wheels that can safely and qualitatively be used for the grinders, then it would only motivate more smiths to get their own great grinders :D

 

 

as an example - i saved 50% cost on one of "my" projects, when i was young, .. i spent nearly a month researching suppliers for a mechanical/hydraulic project my dad worked on, and ended up finding suppliers that were closer to home, better quality, and 50% lower cost .... :)

Edited by vihalvor

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uhmm.. something happened, when i tried to edit my last response...

You make very good point.. i guess im just a bit of a "wannadoitbetter" guy :P .. i hate settling for specialist retail store prices, when i know that out "there" there are alternatives that are used in other industries, but just not known well for DIY'ers like us ...

Spending 250 $ gets me really annoyed, when i 3 weeks later find the same item online, with the same specs, but aimed for a different market/industry, and a fraction of the cost.. :P

 

I did some MORE research and found THIS picture that explains a lot more on the last roller i showed... now.. for a grinder that isnt using a big contact wheel, like the 8-10" wheels, but just a platen style .. maybe it could work ? .. im thinking about that durometer thingie.. ?

 

Chain-Roller.jpg

 

oh .. and a quick search on google yielded a weird find ...

http://www.walmart.com/ip/Dynabrade-Contact-Wheel-Assemblies-db-11078-contact-wheel-assy/15664651

.. could anyone check out what that really is ? .. for you USA guys... if thats the real thing.. it COULD be worth checking out :)

 

.. and if anyone thinks im bugging in too much here and would like me to shut my yap.. just tell :P ... i have thick skin :P

Edited by vihalvor

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uhmm.. something happened, when i tried to edit my last response...

You make very good point.. i guess im just a bit of a "wannadoitbetter" guy :P .. i hate settling for specialist retail store prices, when i know that out "there" there are alternatives that are used in other industries, but just not known well for DIY'ers like us ...

Spending 250 $ gets me really annoyed, when i 3 weeks later find the same item online, with the same specs, but aimed for a different market/industry, and a fraction of the cost.. :P

 

I did some MORE research and found THIS picture that explains a lot more on the last roller i showed... now.. for a grinder that isnt using a big contact wheel, like the 8-10" wheels, but just a platen style .. maybe it could work ? .. im thinking about that durometer thingie.. ?

 

Chain-Roller.jpg

 

oh .. and a quick search on google yielded a weird find ...

http://www.walmart.com/ip/Dynabrade-Contact-Wheel-Assemblies-db-11078-contact-wheel-assy/15664651

.. could anyone check out what that really is ? .. for you USA guys... if thats the real thing.. it COULD be worth checking out :)

 

.. and if anyone thinks im bugging in too much here and would like me to shut my yap.. just tell :P ... i have thick skin :P

 

I certainly don't mind your looking for bargains, but you have more pictures of cheap wheels on this thread than I do of my grinder which in my mind is rather the opposite of a cheap grinder. perhaps a new thread is in order to continue your search for alternatives components.

 

For me I have high quality wheels and I am trying to build a professional grade tool that will last me the rest of my life and do everything I want it too. I am a working professional and this tool is critical to my income. I am not looking to cheap out. If I spent a month shopping every part to its cheapest level I would lose more income than I would gain.

 

For a hobby with no time table and very little cash your approach makes sense, but for me I would only come out behind. For me building a grinder hits me two ways. Money spent on the parts and time spent not earning money. I don't want to count how many hours I have spent designing it from scratch. Trying to spend a 100 hours trying to source parts that are only marginally cheaper just puts the deficit over the top.

 

My mind set says just buy a grinder and get to work and that in fact makes the most sense to my pocket book. However this is something that I have wanted to do for a long time and I am giving myself the time to do this as a gift to myself. I just lost the last 4 days to a sickness in the family so I am quite behind. However I am back on it in the morning. Motor mount and tracking here I come!

Patrick B)

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Here is some of today progress. The motor mount and the tracking are combined on this design. I decided to do this because the tension wheel will spend most of its time about 4 inches off the ground and I did not want to adjust tracking with my foot hehe...

DSC00180.JPGDSC00181.JPG

DSC00182.JPGDSC00184.JPG

 

I surfaced the top of the main body so the motor mount would sit true. Still I slotted the holes so it could be adjusted. I wanted to make sure that I could get it to line up perfectly with the other wheels. Then the tracking will be similar to other grinders except the whole motor will lift or drop on a pivot. I have a Turn buckle that will support the motor from the other end and serve as the tracking adjustment. The Turn buckle is rather sloppy and loose. I may make a new one myself or similar mechanism that works better. I could probably let the motor hang free and put an ajustment directly on the mounting plate, but I like the distribution of stress holding it from each end.

DSC00188.JPG

 

Patrick

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heh. yeah ... thanks for the feedback, guys :)

im definately not one that settles for the best retail price out there, but im also not one of those that saves myself poor :P

i just believe in doing very thorough research before buying :) .. in general, i find that buying at specialist retail stores usually comes at a very high premium, where the same product, given a few days research, can often be found elsewhere at far lower cost... :rolleyes:

That is why i jumped in passionately into this tread.. if WE can find options for wheels that can safely and qualitatively be used for the grinders, then it would only motivate more smiths to get their own great grinders :D

 

 

as an example - i saved 50% cost on one of "my" projects, when i was young, .. i spent nearly a month researching suppliers for a mechanical/hydraulic project my dad worked on, and ended up finding suppliers that were closer to home, better quality, and 50% lower cost .... :)

 

I find, in the long run, it is better to get the tool and then get to work.

Build when building gets you a tool that fits your needs, but source materials that are "plug and play" as often as possible.

"Saving" money can be a trap at times ...and cost you time and money in the end.

 

Ric

Edited by Richard Furrer

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Patrick, I see what's emerging from that pile of aluminum, but not the whole picture. Maybe you're saving that for the end?

Is it a wet grinder?

 

I can attest to Sunray being very good. If you take a chunk out of one accidentally they can be re-tread.

I wouldn't use anything but purpose built contact wheels. Anything not rated for the RPMs isn't strong or balanced well enough. Caster wheels and things like that are not balanced or rated for high RPMs.

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I thought I would be done by now, but there are many delays. I worked on upgrading my electrics most of today. I purchases materials for 20 amp circuit, but turns out that the device manual calls for 30 in my particular scenario...

I needed to get it up, but have not made the stand yet. So today I just screwed a couple of 2x4s to a bench and set her on there. I am pleased with what I have so far. Some of the little things I need for the tension system won't arrive until late next week so that will be another delay. I hope to have it powered and at least test run this weekend. The machines foot print is only 15"x 20" inches and that is a 132" belt on there.

DSC00191.JPG

The turn buckle seems to work well and everything in the build is really solid I think it will be a smooth unit.

DSC00192.JPG

See larger pic by going back in the thread using on of the gallery links. I only have limited ability post right now I think my desktop computer just got fried by some lightening. My net book makes it hard to see all the options.

Patrick

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