Steel Guide Adjustment
If your blade isn't providing straight cuts, we recommend checking out the steel blade guides first. While in use, a bandsaw blade must slide through the center of the steel guides. Additionally, the blade's teeth must never touch the guides. Otherwise, the blade will overheat and lose its sharpness, thereby losing its ability to cut properly.
Back Limiting Screw
Once you've checked on the steel blade guides, the next component you should turn your attention to is the back limiting screw. You should ensure the back limiting screw is in good condition on a regular basis. At the same time, you should also check that it is properly adjusted to prevent the blade's teeth from rubbing against the steel guides, which will damage the teeth and cause uneven cuts or blade failure due to fatigue.
Blade Placement
When installing a new bandsaw blade, the back of the blade must not touch the pulley flange. If the blade and flange are touching, the friction will cause the blade to fatigue and fail prematurely. To avoid this, we typically recommend there to be about 1/16" between the pulley flange and the back edge of the blade. You can adjust the amount of space between the two components by moving the leveling adjustment until you reach the desired measurement.
Be careful not to leave too much space between the blade and the pulley flange though. If they are too far apart, the blade could easily pop off the wheels.
Blade Tension
Proper blade tensioning is essential to any successful cutting operation. Basically, over-tensioning you're your blade is just as bad as under-tensioning. Both can result in uneven cuts and shortened blade life. For best cutting results, you should refer to the machine manufacturer's instructions for proper tensioning or use a tension meter.
We published a detailed blog post about the importance of blade tension last year. You can check it out here.