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Converting a surface grinder to 2 x 72


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I have a surface grinder, an Industrial Abrasives 3b. I have a pretty good idea for the structure for the arm, however, the drive shaft has a 3 inch diameter :( . I want to make my mods reversible, if I can, since I might have need to back to a stone at some point.

 

Most of the contact wheels have a center boss, if I machine that out will the wheel be too flexy? If I make my own wheel (plywood, laminated Micarta, aluminum) how do I get a rubber wheel on it, or do I need one?

 

I'm looking for ideas, so any thoughts you have have (no matter how strange :o ) I'd be willing to listen.

 

I have a mill and a lathe, and a minimal clue how to use them, plus smart friends.

 

Thanks in advance,

 

Geoff

Edited by Geoff Keyes

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

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There are a couple of tutorial over on KnifeDogs Forum under the tutorial section.

Tim Musselman

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As requested, some pics

 

The IA 3b, looks like a gun turret

DSC00073 (Medium).JPG

 

Front view of the head

DSC00074 (Medium).JPG

 

Side views of the head

DSC00075 (Medium).JPG

DSC00076 (Medium).JPG

 

Guard removed

DSC00077 (Medium).JPG

 

Side views, no guard

DSC00078 (Medium).JPG

DSC00079 (Medium).JPG

 

I looked at the tutorials over at Knife Dogs, I like the triangle frame idea, if it will fit. I don't want to interfere with getting to the right side height adjuster. It turns out that the spindle is 2.125, not the 3" I thought. There is a good surface to clamp onto add an additional bolt hole, so the mount won't be hard.

 

I don't have the $ to spend on a custom drive wheel. I have two thoughts right now. The first is using the 10 " contact wheel from my Hard Core (which I never use) and mill out the center to fit, that plus a couple of bolt though stiffener plates and it should be fine. The second is to find a big chunk of aluminum and turn out an Al drive wheel. I'm open to other suggestions.

 

Thanks

 

Geoff

 

PS

 

My aim is to mod the machine in such a way that I can return it to it's original state without too much trouble.

 

g

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

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Doesn't look too horrible to deal with. For the idler arm just build a clamp out of some larger tube and clamp on similar to the existing guard. Then weld a piece of pipe to it that you can nest a smaller pipe into. Place a set screw to hold the arm to whatever extension you need and mount an idler wheel/tracking mechanism at the end of the arm.

 

For the contact wheel, have you looked at Sunray? You can get a nice 70D durometer coated 8"x2" wheel for about $60. They don't list shaft sizes up to 2.125 on their website, but I'd bet if you called them they'd do it no problem. If it were me, I'd shoot to keep the wheels for my grinder because as soon as I re-use something and modify it to the point that I can't go back, that's when I need to go back :)

 

One thing I definitely would not recommend is a straight aluminum drive wheel. One of the things that makes these conversions to useful is the fact that the rubber coated wheel has a bit of give to it. This significantly reduces the danger of taking too large a bite with a hard wheel, and allows for a good finish even if you do take deeper passes.

 

Just my $.02.

 

-d

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Geoff,

I don't have any experience with the conversion you are doing.... so I'm just a spectator on this topic... BUT... I do use a surface grinder with the standard wheels... My only observation is to throw out that chipped wheel you took off arbor .... Don't even consider putting it back on.... any wheel that has a flaw like that, a chip, crack, what have you, is suspect... so any of the old wheels you have that a damage should be treated as trash... you can use them as hand stones and even cut them up into shapes but just don't try to use a damaged one on the machine... For obvious reasons...ohmy.giflaugh.giflaugh.giflaugh.gif

Good luck with the conversion... I've heard they are quicker with a belt than a hard wheel... all though more expensive to run with belts cause they where out quicker than a wheel will... But time is money for most people so I hope it works as you are hoping....

 

Dick

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Geoff

Are we talking about converting to a belt?...I did mine the easist way,I think..I bought a kalmazoo 2x48 belt grinder 0n ebay and used U bolts to attach it to the machine..Then I had a wheel made..My surface grinder used 1/4" thick wheels...1.5" hole so I had a contact wheel made with that size hub..it bolts on or off so I can easily change back to stone..I posted some pictures a while back..if it will help I'll post again...Good-Luck..Arthur

"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." — Mark Twain

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Geoff, you need to find another arbor that fits your spindle. you make the arm so that it clamps to the outside of the spindle where the stone guard clamps. Then use your wheel of choice, and put it on the spindle hub and tighten everything down. put a file on the chuck and turn on the magnet and run the wheel back and forth across the magnet until the wheel is true. figure out what you are going to do on the top for a tracking wheel. when you want to go back to a stone take off the hub with the wheel on it off and put on the new hub and then mount the stone and dress it and grind away. then just switch out the hubs with the wheel or stone to what you need.

Bill Burke

ABS Master Smith

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Arthur, please re-post your pictures, that would be a big help.

 

Here's what I've got going on

 

DSC00114 (Medium).JPG

This is the damaged wheel, you can see that the center hole is 3 inches

 

The part my dirty finger is pointing to is where the stone guard mounts. This is stationary and even has a convenient mounting hole. The shaft size is around 4 inches. Making the mount is simple, split a piece of pipe, weld some ears to it and bolt it on, clamshell style.

DSC00115 (Medium).JPG

 

Here is the problem. This bit spins. Just outboard of my finger is where the stone fits, that step down is 3 inches in diameter. Outboard of that is another step down, that one is 2.125".

DSC00116 (Medium).JPG

 

If you look closely there appears to be an inner shaft which the stepped shaft threads on to. If I could figure out how to get a hold of the pieces, I might be able to spin the outer piece off, which would give me a much smaller spindle to deal with.

 

DSC00117 (Medium).JPG

 

It's possible, likely even, that there is a wrench that slips into the gap between the two large pieces, and another that grabs the notches on the front piece, But I don't have them. I could spend a day fiddling about trying to re-invent the wrenches, or, I could take my 8 inch contact wheel from the Hard Core, which I've only used twice since I bought the machine, and turn it to fit the 2.125 spindle. I also have a quote request into Sunray to see what a custom drive wheel is going to cost.

 

DSC00119 (Medium).JPG

 

Any other ideas?

 

Thanks,

 

Geoff

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

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Hope these help....Arthur

machinary 003.jpg

machinary 002.jpg

NY Party 073.jpg

NY Party 090.jpg

"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." — Mark Twain

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Geoff,

Yes that end "Nut" will spin right off.... if you have a spanner wrench you can use it and give it a rap with a hammer to break it free... or use a square ended bar you can put in on of the slots and give it a rap with a hammer..put some wd 40 on it first...there should be enough mass in the shaft to work ...if not you you will need to go inback of the machine and find some way of locking up the shaft ...

 

the other part you want to remove I would imagine is a cover plate that holds the shaft and bearings together... It won't hurt to take it apart but I think that is part of the way the spindle is mounted and held together so it needs to be assembled to use... meaning you should probably just leave that one alone...

 

the first one you want to take off ... the spanner nut may be doing the same thing ( holding the spindle shaft) and may be needed to be used to run as well... the fact that there is no room to mount a wheel behind it is my thinking...

 

I think you have it stripped down as far as needed to do your conversion...

 

And get yourself some spindle oil and some way oil as well..... that machine will out last you and your grand kids children if it is maintained properly.....

 

Dick

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I still can't understand what the problem is with the shaft..If a grinding wheel will fit OK..get a wheel made with the hub the same deminisions as the grinding wheel..then you can simply change wheels [ belt to stone] at will..I can get pictures of my wheel if it will help...arthur

"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." — Mark Twain

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Most grinding wheels, and most contact wheels for that matter, have arbor diameters of 1/2" to 1". I had to search long and hard to find stones with a 3" arbor, and then they are $50-$200 per :o . I haven't found any ready made contact wheels larger than a 1" arbor hole. I do have a request into Sunray, just to see what a custom wheel will cost, though I'm expecting it to be pricey. This is why I'm talking about converting a contact wheel I already own to do the job.

 

I have also thought that a big chunk of Delrin, or nylon might work. It would be easy to turn the center out, and easy to true up. Unfortunately, a 2 x 8 chunk of Delrin is pretty big $ too, especially since I haven't found a cutoff anywhere, all of the sellers want to sell me a 4 foot piece.

 

Anyone out there have a 2" x 4-8" piece of Delrin or nylon they'd be willing to sell?

 

Thanks for all of the posts,

 

Geoff

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

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try these guys...Contact Rubber Corp.

8635 198th Avenue

P.O. Box 97

Bristol, WI 53104

Telephone: 262-857-2361

Fax: 262-857-9483

info@contactrubber.com

 

http://www.contactrubber.com/

 

I just found the bill for my contact wheel...$135...Built Exactly to My specs......Sometimes it pays to have someone else make something for you...Good Luck

Edited by Arthur

"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." — Mark Twain

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Thanks, Arthur. You are the second guy today to come up with Contact Rubber.

 

Geoff

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

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"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." — Mark Twain

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I have been using a belt conversion for 15 years & love it. I tried most of the things mentioned above and settled on the following:

 

5"x 1" rubber contact wheel. Mine was bought off a tailgate at Batson's and bored on a lathe to fit the arbor. Total cost $5.

I would recommend you not be tempted by a bigger or wider wheel, they require more power and are prone to bogging. Set it up for 72" belts and split your 2". Much cheaper and more variety available in belts. Remember that a surface grinder works by moving the surface of the material under a single point, wide belts are not more accurate. The 5" wheel provides the proper angle of approach to cut without bogging or glazing.

 

Also, If possible move the idler assembly off center, usually to the left. This allows the belt a longer time on the contact wheel before contacting the metal and allows the belt to "settle down". Makes for better accuracy and longer belt life.

The above information came from Dan at Bader Corp. They did some real testing to come with it. Good people.

 

This is one of the most used tools in my shop. Almost every piece of damascus I make goes though it for clean-up and thicknessing. It's fast and accurate enough for folder work.

Hank

henry knickmeyer

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I have surface grinder that I recently got in a couple of boxes and several pieces.

After many hours and alot of head scratching it is up and running.

Can someone tell me what are the advantages of using a belt rather than a wheel?

Also does the belt make contact over it's full width rather than the edge like a wheel does?

Thanks

Steve

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I have surface grinder that I recently got in a couple of boxes and several pieces.

After many hours and alot of head scratching it is up and running.

Can someone tell me what are the advantages of using a belt rather than a wheel?

Also does the belt make contact over it's full width rather than the edge like a wheel does?

Thanks

Steve

 

The advantages of a belt are great for knifemakers. They can take deeper cuts and take material of faster. They "hog" material off. Grinding wheels produce finer surfaces and more precise work, but belts suit the knifemaker fine.

.

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And I thought I was good to go with a hard wheel.

Looks like I see another machine conversion on the list of "sure would be great to have"

Thanks for the info.

Steve

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  • 1 year later...

I picked up and Abrasive 3B as well last weekend Sunday and am working on my own belt conversion, so I figured I'd show a little bit of how I went about it.

 

Step 1 was to get a VFD to run the motor. Not much to add on this note.

Step 2 was the contact wheel, I went with a Bader 8" serrated, without the bushing, which fitted on my spindle perfectly, except the spindle was the same length and as opening in the wheel. No problem, I ground down the center boss a bit, then stuck the wheel on my pentograph and milled up the face nice and smooth. Now it fits the arbor, and I can fasten it in place with the nut. Win win!

 

I should be getting my tracking wheel in this weekend and will post the next steps when completed.

Grinder1.jpg

Grinder2.jpg

Edited by Michael Pikula
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That's awesome, Michael. I wish I had room for a surface grinder in my shop.

 

--Dave

-----------------------------------------------

"It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly; who errs and comes short again and again; because there is not effort without error and shortcomings; but who does actually strive to do the deed; who knows the great enthusiasm, the great devotion, who spends himself in a worthy cause, who at the best knows in the end the triumph of high achievement and who at the worst, if he fails, at least he fails while daring greatly." -- Theodore Roosevelt

http://stephensforge.com

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  • 4 years later...

I know this is an old thread, but I found it while researching my own SG conversion. I see you two have the same Abrasive 3B grinder as mine, so I have to add my own into this thread, post-conversion!

[youtube]

 

There's a video, for now. I'll go snap a pic in a bit and upload that!

Edited by Salem Straub

Please come and waste some otherwise perfectly good time, looking at my knives!

www.prometheanknives.com

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