# table saw belt tightening



## hungrybare (Jul 24, 2010)

Hey guys, newbe here, and I have a problem, I bought a craftsman table saw in pieces and got it together but have a problem with the belt tightening up as I raise the blade. Don't know if there is something missing or something not pivoting the way it should.
It is one of the old craftsman cast iron table saws (1132982940). 
I looked on the diagrams for ordering parts but they are not real clear. I have a picture of the motor, I think there is supposed to be a spring between the motor bracket and the aluminum bracket? 
Also I just have a 2" pulley on the motor but I think it is supposed to be 2-1/2" ???
Any help would be greatly appreciated THANX !!!!!!


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## woodnthings (Jan 24, 2009)

*Belt length?*

I had a similar saw, the belt was 42" or 43" if I recall.....many moons ago.
I think the belt in the photo may be too long? If you lower the blade down, slide the 2 shafts up close to the saw. that *should be the minimum* length belt...if I recall...Just watch the motor pivot as you raise the blade to see if the belt wants to be longer or shorter. Sorry I can't remember which way, blade up or blade down shortens up the belt, or pivots the motor the most.
If the belt tightens up too much, slide the mount in towards the saw. There is no spring needed, just the weight of the motor hanging down pulling the belt tight. There should be some slack in the belt at it's tightest position, but not much. Just not a metal to metal condition. :blink: bill


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## woody woodturner (Jul 9, 2010)

the bigger the pulley the faster it go,s:no:


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## Mr Mac (May 31, 2010)

The belt should be a V 1/2" X 41" and there are no springs between the motor base support and the motor base. If the motor doesn't move freely ensure the pivot arm bolt isn't tight against the base and the hinge pin is lubed enough to allow free movement of the motor. As you raise the blade the motor pivots upward and bet tension remains fairly constant. 



> 14. Lower the blade .....install belt on saw pulley and
> motor pulley.
> 15. Sight along edges of both pulleys and move motor
> pulley so that belt is parallel to the edges of both
> ...


From what I can see in your picture it almost looks as though the belt you have is too long judging by the position of the support but pictures can be deceiving. When I get home in the morning I'll take a measurement of mine to include the pulley diameter and let you know.


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## Mr Mac (May 31, 2010)

Welcome to the forum from MO!

Mac


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## hungrybare (Jul 24, 2010)

Thanx for the information !!!!!! Really helpful Mr. Mac

I guess the 1/4" bolt that is in the slotted hole on the bracket is not supposed to be tight like tightening a belt on an alternator or generator? 
Is that supposed to be a bolt with a collar to prevent it from tightening the the bracket so it doesn't pivot.
The belt I have is 1/2X41" the blade is down as far as it will go in the picture but I only have a 2" pulley and I think it is supposed to be 2-1/2" ??


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## woodnthings (Jan 24, 2009)

You are correct re the slotted hole and bolt. The motor must be free to pivot and the bolt needs to have a spring washer, and not be tightened, to allow it to do so.
The factory measurements regarding the edge of the washer are designed to be with the "correct" size pulley and belt, so that may be an issue. The pulley sizes affects blade speed also, so it's best to get the correct size. Assuming the motor is factory issued it could be a 1750 RPM. If it's 3450, that may explain why a smaller pulley was substituted. If I recall an my older saw, I used a 3450 motor and 1 1/2" pulley. The parts diagrams do not usually specify pulley sizes, so some more help may be needed. Maybe MrMac has the same saw? I would get a strip of emory cloth and wrap sand the 2 shafts which slide into the casting and clean them up good so you can easily adjust the belt tension by referencing the washer to the end of the slot.  bill


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## Mr Mac (May 31, 2010)

woodnthings said:


> You are correct re the slotted hole and bolt. The motor must be free to pivot and the bolt needs to have a spring washer, and not be tightened, to allow it to do so.
> The factory measurements regarding the edge of the washer are designed to be with the "correct" size pulley and belt, so that may be an issue. The pulley sizes affects blade speed also, so it's best to get the correct size. Assuming the motor is factory issued it could be a 1750 RPM. If it's 3450, that may explain why a smaller pulley was substituted. If I recall an my older saw, I used a 3450 motor and 1 1/2" pulley. The parts diagrams do not usually specify pulley sizes, so some more help may be needed. Maybe MrMac has the same saw? I would get a strip of emory cloth and wrap sand the 2 shafts which slide into the casting and clean them up good so you can easily adjust the belt tension by referencing the washer to the end of the slot.  bill


Correct in everything! I measured my pulley and it is the smaller one (1.5") since my saw does have the larger 3450 RPM motor. Get things loosened up like in the manual and you should be good if you have the right motor/pulley combination.



hungrybare said:


> Is that supposed to be a bolt with a collar to prevent it from tightening the the bracket so it doesn't pivot.


No, there is supposed to be a flat washer and a spring washer but no collar. I just have mine backed off so it isn't binding.



hungrybare said:


> The belt I have is 1/2X41" the blade is down as far as it will go in the picture but I only have a 2" pulley and I think it is supposed to be 2-1/2" ??


Are you measuring your pulley from the outer rim or from the drive surface (hub)?

Mac


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## hungrybare (Jul 24, 2010)

*V-pul 2-1/2d*
*Part for , Model # 113298240*
Number: STD328022Category: 


I found the parts listing at sears website, I figured the pulley was 2-1/2" so that is what I got from fleet farm. Says 2-1/2" DIA. 5/8" bore, but you are right, the HUB only measures 1-1/2" and it is the original motor 3450 rpm. So I think this should be back to original specs after I get a spring washer (thought I had some here but I guess not). THANX FOR ALL THE HELP GUYS !!!! REALLY APPRECIATE IT


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