On a typical wood or metal cutting blade the hook or of point of the blade should be pointing down for a vertical blade bandsaw, or for a horizontal blade saw the hook of the teeth should be pointed such that they enter the workpiece first as the blade moves. During regular cutting on a well set up bandsaw the blade will move or bow backwards a bit as you press the workpiece into it. The side guides will assist in keeping the blade cutting straight, but they are not an iron lock on the blade forcing it to cut straight.
There are a lot of cutting forces working on that thin piece of metal that is a bandsaw blade, so if you can’t attain sufficient tension then nothing will be right! Generally speaking we recommend 30,000 PSI of tension for bimetal blades, though in most applications you won’t start running into serious problems until you have half that tension. Tooth chipping would in fact be the #1 cause we see for blades not cutting square, and particularly where they cut on a curve. Just as happens with a worn blade, too many teeth actually reduces the material removal power of the blade and if combined with an over-optimistic down feed rate, won’t speed up the cutting so much as cause the band to twist and writhe itself crooked within the cut.
Another very common cause of not tracking square through a cut is blade tension. Blade tension on these little saws is high… higher than you might ever imagine. If the blade isn’t precisely 90° to the table then there’s no way you’re going to get a square cut, it WILL drift.
The original question of the saw not cutting square vertically is due to the fact that the blade cuts in the direction its pointing. What has been missed so far is that if the arm doesn’t fall square to the vice table, the blade, even if adjusted as above, it will still not cut square vertically. To know if you’ve got this problem, using 6″ engineers square like in the photo above, place it so the blade of the set square just touches the tip of one of the teeth that is set toward the vice and clamp it up hard.
7 Re: Band saw cuts crooked Blades tend to cut crooked as they get dull and also as hammack said make sure you’re not trying to cut to fast. 8 Re: Band saw cuts crooked I assume you are talking about a Horizontal bandsaw and the saw has cut straight at some point. 15 Re: Band saw cuts crooked went to home depot today and bought a new blade for the band saw.
If the blade twists and the work piece is harder to push through the cutting area, replace the blade. Loose blade tension can also cause the blade to twist and veer off course when cutting the work piece. Check blade tension by pressing in on the side of the blade using a gloved finger.
Having the blade ride centered just behind the gullets between teeth makes a huge difference, as well as learning to set the blade tension properly. Normally the bearing behind the blade should not be in constant contact with the blade, except when you are pressing the work into the blade. You can check this with a transparent protracter, but making one cut with a wood block, then flipping it upside down, checking to see if the blade still fits in that slot.