Troubleshooting a "Wavy" Cut

Sawyers suggest reasons that a portable bandsaw blade might wander at the beginning of each cut. August 30, 2005

I am cutting cottonwood with a Woodmizer LT40 and get a wave in the head of the log about 2" in. When I turn the log around it starts a new wave and cuts the butt flat. The wave is 6" long 1/2 at the highest point, and it cuts clean after that though. Does anyone know what this is all about?

Forum Responses
(Sawing and Drying Forum)
From contributor I:
One cause may be if the blade hits the log, possible deflection occurs slightly. But a 1/2" is extreme on a 6" run. I always creep into the log until the blade is fully seated then I power the feed.

From contributor R:
The hook angle on the blade may be too much. Harder woods need less hook angle. Try a blade with a 2" or less angle and that may solve your problem.

From contributor W:
I use a slow feed rate for about the first 4" to 6", then increase the feed rate. Cotton wood is pretty soft.

From the original questioner:
I currently use Woodmizer blades. I use certain blades for soft and certain blades for hard. The logs have been 10' and longer, and it's the first 6" of the head of the log.

From contributor B:
I would check the plow angle of the blade. The blade will level after first 6" or so.

From contributor G:
I would suggest tightening the drive belt on your LT40. It is very common to experience the symptom you describe when the rim speed slows upon entering the cut then catches back up sawing flat the rest of the way.