Does anybody have any suggestions on how to get a bandsaw mill to cut straight through the knots in red pine?
I have a Kasco mill and am having trouble cutting straight in pine. I have tried different sets and hook angles but don't seem to be getting it right.
I use a blade with 8-degree hook and .019 to .020 set. The blade must be sharpened with the tooth tips square to the blade body, not to the set tooth. Sometimes I have to slow my feed rate slightly to keep the blade cutting straight.
Also, use a lot of blade lube to keep the pitch from gumming up the blade. And a lot of pith on the blade will sometimes turn or angle the blade as it goes through the guides making the blade rise or dive in the cut.
The blade will find it easier to take a smaller cut (uses less energy that way), so it will try to go sideways. Even though a sharp blade is critical (and judge the sharpness by the side corners of the teeth), if you increase the feed with a sharp saw, then, when you hit the knots, you are in the saw boat -- sawing too fast (or not enough energy to cut the dense knots). So slow down!
It is critical that the saw have as much tension on it as possible, and a wider saw will do better because the back of the blade will help steer the blade straight. A thicker saw will go straighter, but the bending around the wheels is more difficult. Finally, keep the guides as close to the wood as possible.
Gene Wengert, forum moderator
My mill is manual, so I'm adjusting the feed rate by watching where the knots are and listening to the sound of the engine. I used water as a lube with liquid dishwashing soap added.