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breaking bandmill blades9/24
I've had a Norwood sawmill since 2005 and have been using it not fulltime but regularly. During the first 3-5 years I don't know if I broke even one blade, but at some point they did start breaking and now I get one sharpening out of them before they break. I'm scratching my head, wondering what has changed. What could cause this?
The 2 biggest blade breakers are worn v belts where the blade hits the wheel and have the bearing or flange behind the blade too close, I run the flange on my mill 1/4" behind the back of the blade as Cooks recommends with excellent blade life. Steve
I agree with Steve. Are they breaking at the weld--bad blades then? If not, then the blade is getting high stress momentarily, possibly on the back edge. This is what happens when belts are loose or backup bearing or flange is not correctly located or working. Non-smooth feed can also be a cause.
I assume the gullet is still the same shape and with no sharp edges or turns. A sharp turn concentrates stress.
A dull blade is also more likely to break.
Any change in blade tensioning?
Next time a blade breaks, check closely to see of you can see any other cracks. Note their location. Let us know.
Thanks for responding, Steve and Dr. Wengert. I'm going to study my mill tomorrow and see if I can understand what you are saying. The blades are breaking when they are still sharp and at somewhat random times and not at the weld. I haven't changed the tension I set the blades at either. I'll check back with you after I study my machine. thanks
I looked at the drive belt and couldn't see something that was noticeably worn, but when I checked the blade rollers I did see that the shoulder on one of them was contacting the blade, while the other one was about 1/4"away. Is this what you were speaking about, Steve. Anyway, I adjusted the roller back and used my mill that day and yesterday, with no blade breakage. I had no idea. Thanks Steve.
Cooks sawmills has a GREAT in depth instructions on (re)setting up your saw blade for optimum performance. IT doesn't pertain to any certian brand NOR is Tim trying to sell you on his parts or brand...it's simply correct blade alignment.
I run my Hud-son Farmboss for approx 2 yrs at Hud-sons specs ( I was a dealer and they train you in their "proper" set-up) with ok results...but after following Tim's advice/instructions and thoroughly setting and aligning it saws GREAT now. Ft Lb specs are important to get for each brand, thickness and style of blade your running. I run 2 brands ( at least until I wear the first brand out) with 2 greatly different ft lb specs.
The guide too close is probably the issue BUT why did it change position??? is there a bearing possibly giving down??
Glad to hear you got it going.
Have a Blessed day!!