Why won't my my band saw's blade move?

Question

I recently purchased a used 12” Craftsman tilt head 2 speed band saw on Craigslist. It worked when I tested it at the previous owner’s place, but when I set it up at home and turned it on. The blade didn’t move. If left on for a bit, the blade and blade wheels began to move and so I attempted to cut wood. However, the saw slowed to a halt before making barely a dent in the wood. I’ve checked underneath to see if the belt was off. It is not, and when the motor is turned on the pulleys turn along with the belt. This may help: when I transported it, it was laid on its side with the blade pulley directly beneath the blade wheel it turns (both sitting horizontally), whereas when upright, they sit side by side and vertical. Any idea what could be wrong? Hey all! OP here. I appreciate all your input and advice. I was researching a lot before asking this question and thought that it might be a key slippage issue like Caleb said. And maybe that’s why the blade moves and sometimes it doesn’t. Perhaps the shaft catches sometimes and other times doesn’t. I looked and there IS a key in the key way of the bottom blade wheel’s shaft. However, I do not see one in the key way of the pulley shaft. I’ve also noticed that the belt is worn. I want to order a replacement belt and was thinking of using a link belt but I’m unsure if it would be too thick to pass from one pulley to the next within the confines of the motor mount. Anyone know what width the belt is suppose to be? The model number of my saw is 113. 248320. Let me give you some more information: when I turn the blade pulley by hand, the blade wheels turn along with the blade. Also, when I pull on the belt of the pulleys, it doesn’t slip and it turns the pulleys and all of those in turn, turn the blade wheels. When I turn the blade wheels by hand they spins smoothly (for how old the saw is), but the pulleys don’t move when I spin the blade wheels by hand. Not sure if that is supposed to happen.

Answer 1

I can't say exactly what's wrong with your saw, as I don't think we have enough information, but perhaps I can help you help yourself...

Bandsaws are pretty simple: a motor turns a pulley, which drives a belt, which drives the lower wheel, which moves the blade. If the blade isn't moving, you'll find the problem in one or more of those components.

First, unplug the saw. If you're going to poke around inside the saw, it's best to be safe.

Open up the top and bottom wheel compartments and confirm that the blade is sitting more or less centered on the wheels. It might not be exactly centered -- that's fine -- but it shouldn't be entirely off either wheel, or looking like it's about to fall off. Try turning the wheels by hand; they should each turn smoothly and fairly easily. If they feel rough, or if they don't turn at all, or if they make unhappy sounds, the wheel bearings may need to be replaced. If they do turn well, move on...

When you're using a band saw, you need some tension on the blade. How much is a matter of some debate, but at least enough to hold the blade straight and provide enough friction between the blade and wheels to drive the blade. If the blade looks to be installed correctly but it doesn't move when you turn one of the wheels, there's almost certainly not enough tension. It's good practice to de-tension the blade when you're not using the saw, so it's pretty likely that the seller did exactly that after demonstrating that the saw worked. There's a knob at the top of the saw that moves the top wheel up or down to increase or decrease blade tension; use it to add tension so that turning one wheel moves the blade and turns the other wheel. Also, when you press on the side of the blade, it shouldn't deflect a lot. (I'm being purposefully vague about how much, but let's just say that if you can easily move the blade 1/8" with the guide blocks out of the way, add more tension.)

If turning one wheel makes the other wheel turn the same amount, and if that wasn't the case before, then the blade tension might've been the only problem. Close up the saw, plug it in, turn it on, and see how it goes.

If the blade still isn't moving, or it's only moving a little, it's time to take a look at the motor, the belt, and the pulleys. If you can hear or see the motor turning and the blade isn't, then you'll want to look at whether the belt is installed, and whether it's properly tensioned. Unplug the saw again, remove whatever cover is over the belt and pulleys, and try pressing on the belt. As with the blade, it should deflect a little but not a lot when you press on it. Try moving the belt and notice whether the motor turns easily, and whether the wheel connected to the other pulley moves. Pulleys are often fixed to their shafts with a piece of square stock called a key, and if one of the keys fell out when you moved the saw, it'd make sense that the pulley might turn on the shaft without actually driving (or being driven by) the shaft. So, check for those keys, and see if you can turn each pulley without the shaft moving along with it.

The last thing that could be wrong is the motor. If the motor isn't turning when you turn on the saw, or it's turning but not much, or with little power, then there might be a problem inside the motor, or the motor might not be getting enough power. Try plugging it into a different outlet, one that you know works for other machines.

Good luck! Also, I've seen manuals for that saw around online, and there are a number of videos on YouTube like this one that might be a helpful introduction to the saw.