Before tuning it up, loosen the guides and wheels away and square the table to the tensioned blade. Then follow these steps in order:
- First, adjust the upper wheel so the blade is tracking at the center or just to the front of center of the wheel tire. (You can see this with the cover removed, and adjust it with the nut/wing nut in the back).
- Now, make sure the blade guides are adjusted so they don't deflect the blade to either side (when looked at from the front), so they contact the blade just behind the gullet of the teeth, but not against the hooked teeth themselves, and are just tight enough to allow the blade to run freely (including the weld). (If your guides are worn and out of flat, you may wish to dress them on a sander before adjusting them against the blade.) Adjust the guides both above and below the table. At this point, ensure that the guide bar moves up and down easily and locks into position without torqueing the guides against the blade.
- Finally, adjust the bearings behind the blade, so they just kiss it, and turn freely when you revolve the bandsaw wheel. They will support the back of the blade when pressure is applied against it during a cut, and help immensely to keep the blade tracking straight.
At this point, check the cut by trying to follow a straght line penciled on a board. Some blades will naturally tend to veer slightly on a diagonal, depending on how they are sharpened, and you may have to adjust your fence to compensate for this "drift".
But if you follow the steps outlined above, and have a good sharp blade to begin with, you should be able to split a line.
If you follow these tips and they prove helpful, please let us know your problem is solved. Otherwise, give us a little more detail and someone will be happy to follow up.