Replies

1. 
   WayneL5 | Sep 23, 2003 10:33pm | #1

   The pulley on my Craftsman table saw has been coming loose for 15 years.  I never found a permanent solution.  Checking the set screw for tightness every few months seems to be sufficient for the amount of use I give it.

   The belt would have to be worn quite badly for it to be the cause of your vibration, but they're not too expensive, so if it looks bad to you replacement wouldn't hurt.

   I would try the following.

   • Remove both pulleys.  Make sure the bores are clean and there are no burrs.  They should fit fairly snugly on their shafts without having to mash metal to get them to slide on.  Replace them if the belt grooves are badly worn or if they are bent.
   • Check the threads that the set screw screws into and clean them up if needed.
   • Buy new set screws.
   • Inspect the keys (loose piece of metal which rides in a groove in both the shaft and pulley and keeps the pulley from spinning on the shaft).  Replace them if they are mangled or bent.
   • Check that the motor is mounted so it's shaft is parallel to the blade arbor shaft.  If they are not parallel it can pull the pulley along the shaft.
   • Clean the pulley bores and shafting.  Reassemble and align everything.  Make the set screws very tight.  You might try Loctite (the reversible kind).
   • Make sure whatever tensions your belt works properly and freely.  On many saws it's just the weight of the motor which tensions the belt.  Make sure it can move freely and not hang up.

   By the way, there are many types of keys.  The two most common are parallel, which is just a straight bar with parallel sides and a rectangular or square cross section, and Woodruff, which are half-moon shaped.

1. 
   wendy | Sep 27, 2003 01:23am | #5

   Hello WayneL5,

   I picked up a new pair of cast iron pulleys today only to find out that they do not fit. The wood drift key.... the metal "key" that fits into the groove of the motor arbor.... doesn't fit the groove on the pulley. I brought that to the attention of the man in the store but he said all I had to do was give it a little nudge and it should fit fine. I even brought in the wood drift key and the alluminum pulley with me so I'd make sure they gave me the right part. Well now it looks like I will have to return the pulleys I bought today. I wonder if I could just buy a smaller wood drift key. Probably not hey? the wood drift key  would probably wander around the groove in the motor arbor. I've got to find a pulley that fits the wood drift key that came with my table saw. Unless I could get someone to machine the groove in the cast iron pulley to fit the wood drift key.  Has anybody else had a problem finding replacement pulleys for their table saws?

   Wanda

1. 
   tyler | Sep 27, 2003 02:33am | #6

   Wanda,

   Woodcraft sells a machined pulley kit with segmented belt for the Craftsman TS. I tried the $45.00 fix on my former saw and it took all the dance right out of it.This saw would walk all over the shop till I installed the mod. Took a little finesse and a lot of cursing but I finally got a snug fit.

   Though the new Uni-Saw is a much better machine, it doesn't have nearly the number of memorable projects on it. Three houses rehabbed, all the kids toys, tables and 2 doll houses were made with that old thing.

   One other thing that may not be suitable for a small pulley, but I use a hose clamp on the wood drift key of my sailboat Aux. drive shaft. Never lost it or had it  or loosen up on me.

   Good Luck

   Dusty

   Edited 9/26/2003 7:37:34 PM ET by Real dusty

2. 
   WayneL5 | Sep 27, 2003 04:30am | #7

   Keys and keyseats are standardized.  So, for example, if the shaft is 5/8" diameter the key would be a 3/16" square key.  However, key stock (the material that the key is made from) comes in different classes of fit.  A Class 1 fit is fairly free, and the key should fit in easily.  A Class 2 fit is a relatively tight fit, and you may need pressure to force the key in place because the key may be as much as 0.001" wider than the seat.

   Assuming the key is the correct nominal size, you have a couple of options.  You could take the pulley with you to a hardware store and try the keys there.  They may be a few thousandths of an inch smaller and would fit the pulley.  Or, you could inspect the pulley and key to be sure there are no burrs, and force the key into place.  Or you could take a fine file and open up the keyseat in the pulley slightly.  You should only need to take a thousandth of an inch or so off, so don't hack away at it.

   It's ok if the key is slighly loose in the seat of the shaft.  You could have as much as 0.004" of slop and still be within the ANSI spec for keys and keyseats.

   Someone suggested earlier to install a second setscrew at 90° to the first.  It's a good idea and commonly done in industry.  You have to have enough material on the hub, though, so you don't weaken it.

3. 
   IMERC | Sep 27, 2003 05:21am | #8

   Some other things to consider.

   Keys do come shouldered by a lot or a little. Looking at the key from the end it will look like a blocky "T". Wide range of sizesto pik from. They are mostly used on worn slots of the pully or motor shaft or dissimilar sized slotting.

   Use Lock Tite blue or green. You'll regret using red.  

   Who ever invented work didn't know how to fish....

4. 
   Steinmetz | Sep 28, 2003 06:46pm | #11

   Wanda, A Wooddruff key is shaped like a half moon. It is used to fit a circular milled slot in a shaft which will receive the key and prevent it from shifting.

   When inserted properly, a small non rounded edge stands out above the shaft. This will engage with the 'broached' slot in a matching pulley or gear.

   Your shaft has a slot that starts from the shaft's end and continues to the pulley placement area.  The 'key you need is rectangular and should slide into the groove and also the broach on the pulley.

   Sometimes it's neccessary to file the flat key to fit easier. Also round off the sharp edge on it's top where it enters the pulley.

    A small mill file will do that for you. Stein.

   Most employees in hardware stores are one step higher on the 'Smarts' column than a hamburger flipper these days.

   Edited 9/28/2003 11:54:23 AM ET by steinmetz

2. 
   k9s | Sep 23, 2003 10:53pm | #2

   I also have an older craftsman that had the same problem. Aparently the aluminum pulleys that come with the saw expand at a different rate than the steel arbor and will loosen over time no matter how much you tighten them. The solution, and and best money I ever spent, was was to buy one of the kits from Woodcraft that has balanced machined pulleys and a link belt. Problem solved and absolutley no vibration.

3. 
   Steinmetz | Sep 23, 2003 11:41pm | #3

   Wanda, Been there done that!  Two causes of your pulley problems come to mind.

    1; the hanging weight (Motor)is a bad piece of engineering (Cheap, but sloppy) since the process of raising or lowering the blade also raises and lowers the motor.

   The more acute the the relationship of the 'Weight' to the height of the blade, the more the motor 'Dances' This sets up vibrations which tend to loosen set screws and pulleys. 

    2: The belt wears in such a way that it 'bottoms'  in the 'Vee' of the V-belt's pulleys and consequently looses its wedging action and slips and heats the pulleys (which loosen the set screw even more) The flat key tends to wander in it's keyway and aggravates the situation even more .

    If you notice, in the area of the motor mount, theres a wing nut. This is used to hold the weight of the hanging motor in the best tension where the wedging effect is optimum and the dancing is mitigated.

    Unfortunately, this must be adjusted every time you raise or lower the blade. Most people don't bother, as it is a royal pain I T A.

   I would buy a segmented belt to replace the origanal belt. Buy TWO set screws (Shorter)

   and a new key.

   Line up both pulleys so that they are parallel and tighten the short set screw. THEN, add the other set screw (Insurance) on top of the first.  Use the wing nut when you raise or lower the blade  G'luck, Stein.

   
   

   ---

   Edited 9/23/2003 4:45:43 PM ET by steinmetz

4. 
   billyg83440 | Sep 23, 2003 11:45pm | #4

   Machined pulleys is the best bet.

   Something you can do for less cost, that may solve this problem, is to take the pulley off and add a setscew 90 degrees from the existing setscrew. Then replace the pulley and tighten both setscrews.

   Not hard to do if you use a center punch to make a divot so the drill bit doesn't wander. Put the pulley in a vice so you're drilling straight down and try to keep the drill as straight as possible, or use a drill press if available. It's important to hit at least close to the quadrant (center) of the shaft hole on the inside. then tap the hole and put in a decent setscrew. Clean any rough edges off the inside tapped hole before reassembling. If you think the hole is too far off center, flip the pulley over and put the hole on the other 90 degree mark.

   Not trying to talk down to you, but many people haven't done much metal work. If you know how to do this, this'll be like telling you how to use a doorknob. Key is use a center punch and to reverse the tap every couple turns in until you hear a click, then resume cutting. This click is the metal shavings the tap has cut shearing off. If you don't regularly do this you can either bind up the tap and break it, or more likely in aluminum ruin the threads you are cutting by rounding them off with the long shavings binding in the tap.

5. 
   fredsmart48 | Sep 28, 2003 04:06am | #9

   bearing supply sells pulleys of different sizes and quality.

1. 
   k9s | Sep 28, 2003 06:10am | #10

   Check t o see if there are any burrs on the woodruf key. When I removed the original pulleys from my saw the keys were burred making removal very difficult. File off burrs or better yet but new keys.