I have an older Craftsman band saw that is very difficult to get the blade back in place and it tends to toss the blade often. It makes it annoying to use the tool. I'm wondering if there is a common set of causes for this behavior that I might be able to use as a diagnostic checklist.
Your saw may be poorly adjusted.
A properly tuned band-saw has the wheel axles exactly parallel and the wheels in the same plane. The axles can be adjusted using the tilt screw on the upper wheel.
If that doesn't help than it may be the crown of the wheels is too flat. Put a ruler on the wheel and see if there is enough of a crown left. If not then you will need to replace the tire or wheel.
Not in any particular order:
- Not enough blade tension
- Blade alignment incorrect - adjust the wheel angle with the provided knob. The teeth gullets should be in the center of the tire of the adjusting wheel.
- Blade thrust guide not adjusted properly allowing the blade to be pushed off the wheel. Less than 1/16".
- Very worn tires
A dull bandsaw blade will tend to move to the side as well. I've never had it move to the point of falling off but that may be something to look at too.
Recently had the problem of the blade sipping off and taking the tire with it' Finally found the set screw on the drive wheel loose and the wheels out of alignment.