This question came from Ralph. He wrote:
“Al, I read your comments regarding band saw adjustment but have something a little different. I just got a 2004 Laguna LT 18 and got the guides set per instructions, and the tension is per the scale on the saw, and I’m having problems with drift. I’m using 1″ carbon tipped resaw blade that came from Laguna. I’ve done a number of test cuts preparing to resaw some 12″ hard curly maple. But the blade runs to the right in a slight curve on the top of the test piece, but cuts straight on the bottom of the test piece. I’ve got the blade opened up all the way up, 12 inches. the piece I’m practicing on is about a 5″ thick piece of hard maple. What am I doing wrong. This is the first real band saw I’ve had so don’t really have any experience. Thanks for any advice.”
My reply was:
“Hi, Ralph. Thanks for writing to me about this issue – it CAN be somewhat difficult to resolve on your own, it is also frustrating, and it can get quite expensive if you are using expensive wood. I am wondering what you mean by the following: …maple. But the blade runs to the right in a slight curve on the top of the test piece, but cuts straight on the bottom of the test piece. I’ve got the blade opened up all the way up, 12 inches. the piece I’m practicing on is about a 5″ thick piece of hard maple… Do you mean that the cut surface on the test piece is slightly rounded, as opposed to flat? It sounds like the blade tension is the issue, if I read your statements properly. The tension adjustment scale on most band saws is WAY off. I find that I the flutter method is the best way to adjust the blade tension, as I explain in the write-up. BUT it is sometimes difficult to tell with such a wide blade when it flutters. How many teeth per inch (TPI) does the blade have? I would highly recommend using a blade with no more than 3 TPI. Also, you might want to try the following:
- Increase the tension by 1/4- to 1/2-turn increments, and do a test cut.
- You can do this on the same piece, by simply cutting a distance of a few inches each time.
- Then look at the surfaces you just cut, and select the one that gives you the best cut
- You will likely have to replace the blade – the stock blades that come with the machines are usually not the best, and are intended for “normal” cutting, nor for resawing wide boards.
Please let me know if any of these suggestions help you in any way.”
I have a request for any of you reading this: I have not heard from Ralph again. If I missed something about the Laguna 18, please leave a Comment, or drop me a note via e-mail. Thank you, friends!
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About Al Navas
Thanks for your contribution, Mark!
You make a good point, in suggesting lowering the upper guides. My first thought was identical, but I see where he is coming from. He will be resawing at full height, and it made sense to leave the upper guides all the way up.
I hope Ralph will read this and follows your suggestion, though; I also would love to hear from him again, to let us know if this adjustment (partially or fully) solved his problem.
Hey Al,
I think you’re on the right track with respect to tension potentially being the cause of the bowing (or curving) in the cut. It may be worth noting that for the flutter technique, the blade guides need to be completely backed off before checking for flutter.
From the brief description that was given, I would also point out the he should lower the upper guides from the 12″ down to just about 1/4″ above the top of the work piece and that may also alleviate the issue that he is having.
With respect to drift of the cut, that could be the blade itself (a normal thing) or where the blade is riding on the wheels if they are crowned. In any case, the fence can easily be adjusted to account for any drift in the blade and then the cuts should be straight and true.
–Mark
http://thecraftsmanspath.com