When to Change Bandmill Blades
How can you tell when a bandsaw mill blade is getting dull? November 27, 2006
Question
I'm curious as to how the bandmill guys determine when to change their bands. I've heard some sawyers watch for less than perfect cuts, especially around knots, others that saw for X number of bd ft, then change, etc. Maintaining the band blades for their maximum lifespan would seem to be important.
Forum Responses
(Sawing and Drying Forum)
From contributor D:
I use several indicators. Less than perfect cuts is one indicator. I also listen to the motor. When it starts laboring, it is time to change. A dull blade also makes a different sound on the guide rollers. If the mill starts to slow down, it is time to change. But the best method is the cut before the blade breaks or dips.
From contributor P:
My mill is a manual push type and the 1st dulling blade indicator is hard pushing the mill through the log. A second indicator is wavy cuts from start to finish. Like contributor D said, the engine definitely bogs down as the blade dulls some. You can also run your finger over the blade tips when the engine is off and the blade is idle and feel a difference on a dulling blade. Hardwoods like oak and hickory seem to dull my Wood-Mizer blades at the 500-700 brd. ft. range. I'd rather change a dulling blade more often than push the issue and lose my cut quality or break a blade.
From contributor B:
Unless you hit a nail (or, in my case the log clamp), the blade dulls gradually, so you don't notice it. If the mill has a hydraulic feed, watch the end of the cut. If the mill lunges forward as it exits the log, you know that you were using a fairly high pressure on the feed, which indicates a dull blade.
From the original questioner:
I had, like contributor P, a manual push type mill, and didn't have much problem identifying a dull blade, but now with my big orange machine, it's a little tougher to ID. Contributors D and B, I'm curious as to what type of mill you fellas run? I have noticed that there are changes to the sound of the mill, and one of the causes apparently must be dulling bands. I sure appreciate the advice - might save me some coin on steel if I get more proficient at recognizing when it's time to change, especially since a band pushed too far before a re-sharp can break prematurely, as I understand.
From contributor D:
I have a Baker/Enercraft HTL 30. It has a 20 hp Kohler powerhead. Dull blades will make the old girl work pretty hard. You can notice a different sound in the engine as the blade dulls. I agree blades dull gradually, but there are factors that will accelerate the rate of dulling. A little dirt in the bark will take the edge off the blade quickly. One thing I do is look at what is coming up on the mill. If I'm in dirty logs, I will try to open the log before I change blades.
From contributor T:
I am a certified cheapskate and I am always trying to get as much as I can from a blade, but I listen to the mill, rub my hand over the knots and watch the blade as it exits the log for any movement. When in doubt, change; one bad board is the cost of a $7 resharp.
From contributor B:
I run a Timber Harvester with a hydraulic feed. By the time the 25 hp motor has run the hydraulic pump, there's not a whole lot left to turn the blade, so it's pretty sensitive to blade sharpness. The higher power mills can muscle on through and it is harder to tell the difference.
From contributor K:
I can usually tell on my WM - if you let the blade exit the log and when you traverse backwards, the blade hangs the log instead of coming right back where you just cut.
