Hello all
I have a Sears Craftsman 80" bandsaw. I went to fire it up the other night and when I started pushing the wood through the blade just stopped. The motor kept running and turning but it was like the load was too great. I thought at first that I was pushing the material through too fast so I slowed down. The only other thing that ocurred was the blade had a little trouble getting up to speed. I am wondering if perhaps the motor has lost a winding or maybe I just need to break the whole thing down and clean. What do folks think?
Hopefuly you turned it off immediately.... there are a number of things it could be. un plug the thing first. then check the shaft where the power wheel attaches to the motor. some have set screws,some are just bolted on with washers, and others have a shear pin in a slotted shaft much like a small engine flywheel. if that pin has sheared off that would do exactly what you are discribing. If it is just bolted on, check the nut to see if its tight. when you said "The blade took awhile getting up to speed" are you talking about the motor bogging down or just the blade? was there any unusual vibration preceeding this occurance?
Hey Kirk,
The motor does not appear to be bogging down. It still runs full speed even though the blade stops.
Vibration did proceed this whole thing. I did take the blade off and the bottom wheel and let the motor run for just a few second under no load, it appeeared to be running fine. I replaced the bottome wheel and again the wheel and motor appeared to function together fine.
I had the same thing happen, Kirk is right on, it was the bolt and keyway on the pulley for the lower wheel, happened twice and I finally egged out the pulley, Sears has all the parts online.
Hope this helps.
Vince
Double check the rubber on your wheels too.
Pulley may well be egged out, as Mowhawkbows said. I have one of these saws and the shaft in the lower wheel was worn out of round from the pulley being loose.
I took the shaft out, welded it up and remachined it in my lathe. But, if Sears has the parts, that's the better way to fix it.
Is your belt tension OK? My sears used to slip the belt and require a retensioning every now and then.
I just replaced both "tires" on my pulleys on and oldie Craftsman 14" saw...Sears had the parts online (as mentioned) and I was up and running in a matter of a couple days.
-Rob
Thanks fellas.
The belt tension is currently near maximum, it may be too high. I know about the lower wheel and the key on the shaft but it is not damaged and the wheel still fits snugly. Are you guys talking about the rear pulley, if so it appears to be spinning even when the blade stops. I wonder if the belt itself is slipping. I will do some more checking tonight and let you know what I find.
thanks again for the suggestions.
If that rear pulley is spinning, then it's loose on the shaft. At least the set screws are loose enough to let it turn on the shaft. Often the screws cut a groove around the shaft when they are loose.
That is one i hadn't though of... Jim is right on the money there. Sounds to me like that's it! i had one do that before and i took the pully off and drilled a hole for the set screw to go into....done deal...
have same saw and have had same problem. look around on the floor below the saw. you may find the missing pc of square key that locks the shaft to the lower pulley. reinsert and re-tighten set screws. if you can't find the key or it is unusable, your local hardware store should have a replacement. it is a standard size. good luck
I obtained a band saw for $50 that looked brand new. It had a slipping pulley and the seller could not fix it. I removed the pully and reversed the shaft on the wheel. This put the allen ,(lock screw) contacting the shaft in a place that wasn't worn. My saw works fine with no problems. If this happens to be the problem you have, tightening the screw down will work for a while but you will almost certainly have it come loose again if the shaft isn't replaced or reversed.
Well I took the motor and belt off last night and low and behold the key was missing from the pulley on the back of the shaft.I made a new key from a square screw driver shaft that I had. I think I reinstalled it incorrectly as I cannot reach the set screw. When you place the pulley back on the shaft it isn't suppose to go all the way down is it. I may have to try an remove and inspect it tonight. Thanks for the help fellas.
Abram, that key should be made of very soft metal. a lot of them i've seen are aluminum.
these are made to shear off instead of stoping the motor, but realisticly the belt should spin before that happens. sounds like you got it on the run.
Kirk,
So I probably need to remove the pulley and replace the key with something other than hardened steel. I am just wondering if I have the pulley installed correctly. I cannot get to the set screw but the belt appears to line up correctly.
Go to your local hardware store and get some keystock of the appropriate size and cut it to fit. You should be able to get to the set screw without having to tear into the machine also. You can use a straight edge to line up the pullies.
I would do as Tom stated and I would go one step futher and reverse the shaft. It is an easy process. If you fail to do this it is most likely to become loose again due to the uneven surface on the shaft where the pully spun. You might need to square your blade with the table and then level the machine. This will eliminate the bulk of the vibration. Vibration will loosen set screws.