Taking a Flutter
Woodworking Question and Answer:

Bandsaw Blade Vibration

I am greatly impressed with your Wood Slicer bandsaw blades. I have had a problem while bandsawing and would appreciate your advice. I carefully tensioned the bandsaw blade in accordance with your clearly written instructions. Then when I was splitting a piece of hardwood about 10 inches wide, the blade developed a flutter in the channel where it rises up between the two wheels. (My saw is a 16" machine that looks identical to the Laguna.) The channel is not particularly wide and the fluttering blade made contact with one side of the metal of the channel and is, of course, ruined. I have since lined that side of the channel with polycarbonate (a sort of Perspex). So the blade will not be ruined by making contact with it. But why is the bandsaw blade fluttering? Any ideas? Also, I presume that I can send the damaged blade back to you for re-sharpening. I will be in the USA in a few weeks, so this would be easy to arrange. I await your comments with interest.

Regards.
G.E.
South Africa

I'm sorry to learn of the vibration problem that ruined your Wood Slicer Bandsaw Blade. It sounds as though slowing the blade's surface feet per minute rate when sawing very thick stock accidently set up a harmonic tremor sufficiently severe to cause contact with the left side blade channel. I've heard of this once before, but in that case the harmonic was created during initial tensioning before the user even began cutting wood.

Unfortunately, we have no resharpening facility to which we can refer you. I have spoken with one customer who found a service that claimed to be able to resharpen Wood Slicers at a cost of approximately US$20. Since most of the hardened surface of each tooth would be milled away during resharpening, I conclude it's more cost effective to replace the blade instead.

I like your idea of lining the channel with polycarbonate — that should be all it takes to avoid a repeat of this unhappy episode. I have not yet imagined any foolproof way to avoid stumbling into harmonic resonance when the bandsaw slows under load. Changing the tension setting slightly as soon as you notice excessive vibration will eliminate the problem, but that will help only if the blade hasn't been damaged before you have time to react.

Though too late to help with the present blade, I hope this helps underderstand what happened, and that your next Wood Slicer Bandsaw Blade has a much longer, happier service life.

Sincerely,
Zach Etheridge