# Setting up a belt driven bench grinder



## railaw (Nov 15, 2011)

Hi,

I picked up an old belt driven bench grinder from an estate sale. I had to unbolt it from the counter it was on and brought it home. Now that I want to install it on the platform I've constructed it occurrs to me that I didn't measure how far the motor was mounted from the grinder and don't know the correct distance between the two. Another way to say that is I don't know how to tell if the proper amount of tension is on the belt. Any suggestions? What other info would be useful to know in figuring this out?

Thanks.

BTW, I'm brand new here - if this post should go elsewhere, please let me know.


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## firemedic (Dec 26, 2010)

Welcome to the forum. Are you a wood worker?

Use slotted holes where the motor is mounted so you can adjust the tension.

~tom ...it's better to remain silent and be thought a fool than to open one's mouth and remove all doubt...


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## H. A. S. (Sep 23, 2010)

railaw said:


> Hi,
> 
> I picked up an old belt driven bench grinder from an estate sale. I had to unbolt it from the counter it was on and brought it home. Now that I want to install it on the platform I've constructed it occurrs to me that I didn't measure how far the motor was mounted from the grinder and don't know the correct distance between the two. Another way to say that is I don't know how to tell if the proper amount of tension is on the belt. Any suggestions? What other info would be useful to know in figuring this out?
> 
> ...




That depends on what length belt you are using. 1/2" flex, midway between shafts; is a good starting point. Then adjust from there.


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## DST (Jan 10, 2011)

And consider a twist link belt for better power and a quieter smoother drive


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## mickit (Oct 5, 2009)

The rule of thumb(or so I was taught) is 1/64" deflection of the belt per 1" distance between pulley centers...ie if the distance between the motor pulley and the wheel pulley is 18" the deflection should be 18/64" or 9/32" reduced...just a tad over 1/4". 
Good luck


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## BobRivet (Nov 14, 2011)

*Belt tensioning*

I'm digging into my Photobucket site, but I use a hinge setup with the motor using it's weight to put tension on the belt.

Works great, if I can find my pictures.

I'd take a picture of the actual setup, but I just took it apart to move it to a mobile cart that I haven't constructed yet...:laughing:


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## BWSmith (Aug 24, 2010)

In my travels......it was some old furniture joint down in Highpoint NC......


They had a "factory",pnuematic sleeve or "pump" sander.Its basically a bench grinder as I'm understanding OP.But add a serious dose of steroids,haha.There was a pump sleeve on both ends of a 1 1/4" shaft.....no gaurds.The cool part was how well designed the large CI base unit* was.This is where the motor was housed.Belts came up through base's top,then went around shaft.

Probably from the 30's?Can't remember the "label",which is funny cause we have a bunch of their stuff,duh(senior moment).

*Their base was built in a time when casting uber heavy machine bases was de rigueur.Without goin off the deep end WRT old vs new manufacturing approaches............a decent base can be had,utilizing either gauge metal or cabinet ply as a carcass.The weight can be added with concrete.Usually we limit it to the space under the very bttm of cabmet.BUT.....in certain cases you can suspend a concrete "chunk"(technical term)by heavy springs or whatever......it "can" serve to dampen certain inbalance frequency's.BW


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## railaw (Nov 15, 2011)

Thanks for the suggestions - slotted holes is the kind of simple solution that I simply would not have thought of on my own. Now I can install it and make the adjustments according to the suggested tensions.

I actually saw a hinge-type set up on a belt motor recently: The same sale that I got this grinder I also got an old, small table saw with a 7 1/2" blade. The saw was belt driven and the motor was on a hinge connected to a metal bar on the back. It was in a custom made wood cabinet that had unfortunately rotted to the point that I wouldn't take it into my house. That, combined with the lack of any safety features, rotted wiring, my lack of experience with table saws (and some prodding from my wife) let me to get rid of it in favor of a more modern, and ostensibly safer model at some point down the road. So now I have no table saw. But I do have all my digits.


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## railaw (Nov 15, 2011)

I finally finished setting up my bench grinder last night that had been sitting on the. Basement floor for about 8 months. Based on the suggestions here. Plopped it onto a piece of 1/2" ply and eyeballed the tension for something that would appear to run. The motor is a g e I think 1/3 hp 1750 rpm washing machine motor from who knows when. Will try to add some photos later Not sure if the part the belt goes over is called the pulley? Anyway its pretty dinged up on the grimder side but after spending an inordinate amount Of time trying to get my hardware store chisel to line up at 25degs, I was able to grind it down to kinda square and then freehand sharpen it to sort of sharp on sandpaper and storm door glass. Ie sharp enough to cut hairs on my arm but wouldn't take it to my face anytime soon. First attempt and am pretty happy with it. any suggestions on uncurling sandpaper so it'll stay down on the glass?


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## railaw (Nov 15, 2011)

Anyone know where I can get another one of these fasteners? Current plan is to bend wire hanger into place to hold on the other side where one is missing, but I can probably do better than that.









on a related note, how much competence does it take to put on a new plug and on off switch on to one of these motors? It is a 1/3 hp washing machine motor GE from who knows how long ago.


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## ryan50hrl (Jun 30, 2012)

Not a whole lot, it's 2 or 3 wires probably in wire nuts depending on the age.


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## railaw (Nov 15, 2011)

I got the book "sharpening" published by fww and recommended in The hand plane Book from the library. That book says that starwheel dressers are only good for coarse grinding stones and that a diamond hone is more versatile. I liked the starwheel bc it was really cheap a hf. I havent opened it yet though and want to do as little buying as possible. The stones on he grinder I have need to be trued and have what looks like rust all over though I don know the actual substance. Is. Worth returning the starwheel and getting the diamond hone?


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