Finding bent bandmill blade teeth
Locating and fixing teeth that have been pushed "out of set." January 24, 2001
A setter is fine for pushing teeth out to match the others, but doesn't do a thing for teeth that are pushed out too far. I suspect the hard knots in pine sometimes push a tooth out too far, so it's out .033" instead of say .022", and leaves a deep groove every inch or so. Is there any way to find the odd tooth that's been pushed out? Using a gauge on every tooth is too time-consuming.
I haven't found an economical way, but if it was cutting good before, you probably hit something in the log. Check for metal welded on the face of the tooth. It is more economical to replace the blade, keep on sawing, and tend to the unsatisfactory tooth/teeth later. Write on the inside of the blade with a marker to remind you of what you want to do. The next time you run the blade, the guides and wheels will erase your note.
When I have a blade that shows a bent tooth and marks on the lumber, I note it. When I'm setting this blade I watch for the bent tooth/teeth and bend it back to the right set with the tool that came with the Woodmizer setter. If a blade has hit some metal and I'm going to set it after sharpening, I set the right side and left side as usual and then check the center tooth for straightness. I check it on both the right and left sides. It takes a long time but saves the blade from the trash barrel.
Should raker teeth be checked and set?
I only check rakers if I have hit something, and not always, even then. A raker performs a function--it is supposed to clean out the kerf. I was told the raker was supposed to be straight, so I make it straight. I once overset one side and grossly under-set the other side and found out real quick how important the balance is.
Turn off the mill and sight out the blade against a guide or some stationary portion of the carriage. Rotate the blade slowly (backwards if possible, to avoid snagging yourself). If a tooth is out of line significantly, you can usually spot it in comparison with the rest as it passes by. You probably won't be able to reset it accurately in place, but you can at least point it back toward center enough to eliminate that groove in the board, if the rest of the blade is still sharp.
Try taking your saw and setting the first tooth from your weld up substantially (say .020-.030), then run a test cut. You should see two marks. Assuming that the heavier of the two is your locating tooth, you'll have an idea of where the bad tooth is relative to your test tooth. For instance, if the mark from the second tooth is 3/4 of the way between the first heavy mark and the next heavy mark, your bad tooth is about 3/4 of the way around your blade from your weld.