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Band inquiry

Started by KiwiJake, September 04, 2002, 03:20:20 AM

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KiwiJake

 Just pondering on some facts, to all you bandsaw guys, in a typical day of sawing lets say 2000 bf cutting 6x1 from 15inch logs, how would your bands do, cutting something semi hard like Oak, NOT running into any nails, steel or rocks. How many times would you sharpen your blades and how long would it take, would you keep spares and get them sharpened? How long would it take to change bands? What is the usual life of a band before a new one is required? Once a band becomes dull, is the cutting speed majorly reduced? Will dense knots majorly affect the rise and fall drift of a band blade? Will it also be affected if the sharpening is unequal? What is the TRUE cutting Kerf from edge to edge of apposing cutting teeth? I haven't got a lot of knowledge on band blades as I haven't had anything to do with them, I really would like to gain a little more understanding towards them. I have heard stories and would like to distinguish fact from fiction. Don't mean to overwhelm you guys.
??? :o

BBTom

I will try to shed a small amount of light for you, I remember wondering the same things about one year ago.
Cutting something hard, like oak or elm, I probably change bands every 300 - 500 board feet.  I change because I can see that the blade is starting to heat up in the cut. (tension pressure gauge drops)  I carry spare bands at all times, and it only takes about 3 minutes to change one on my Woodmizer. Dull bands do tend to deflect much easier when cutting hard knots. I use Woodmizer's blade sharpener, so I would be unfamiliar with uneven sharpening, however I can vouch for a complete unstability if the set is not correct. When you hit a nail or something that takes the set out of one side of the band, it will immediately climb up out of the cut. or dive toward the bottom.
The usual total life of a band is one of those elusive properties. Seems as though some will last through five or ten sharpenings, where others will only last through two.  The life is ended abruptly when they go PWANG, and it is time to install another band.
True kerf by blade measurements... The set on the blade is typically .020 ( can be from .018 to .021)each side, the thickness of the band is typically .45 (can be from .38 to .55) so if you add .020+.045+.020 (top set+ thickness+ bottom set) you get .095 or just under one tenth of an inch.
I like to keep from seven to ten bands with me, just in case I have a great treasure hunting day. Some days I will just use one or two bands, some days six or seven.
2001 LT40HDD42RA with lubemizer, debarker, laser, accuset. Retired, but building a new shop and home in Missouri.

Tom

Lots of answers to questions like this.

Q. How would bands do in a typical 2000BF day in oak.


A. I would go through one and a half blades probably.  Blade life is directly proportional to the length of the band.  My Woodmizer band is 13'2" and I would get about 500 to 600 feet optimally.  My Baker has a 17'4" band and I would get about 900 to 1300 feet. Then I would swap for a new blade and save the old one to be sharpened.

Q. how often would you sharpen your bands.

A. I get 4-6 sharpenings on 13'2" Simonds Red Streaks used on a WM LT40.

     I get 2-4 sharpenings on a 17'4" Lenox woodmaster C used on a Baker 3638D.

Q. once a band is dull, is the cutting speed majorly reduced?

A.  Yep, your doggone right it is.  If you keep on cutting then your band life is drastically reduced.  The band will work harden and break.

Q. Will dense knots affect the rise and fall of the band blade.  

A. Yes and no.  If the blade is configured correctly and is sharp then the cut will be straight and smooth.  As the blade dulls, it tends to push off of hard grain or knots.

Unequal sharpening is a moot point with automatic band blade sharpeners.  The fact of the matter is that the blade is either sharp or it isn't.


Check out the knowledge base on the forum and you will find more band blade information.

There is so much to talk about when discussing bands that it's hard to find a stopping point.  Books are written about the subjects you asked about.  I guess the same is true of Circle Mill blades as well.  When you ask a question about blades, you usually just touch the tip of an iceberg. Those are good questions, but each one has answers so varied based on use, operator, material, design, speed, horsepower, lubrication, etc. etc., that a definitive answer is hard to give.  That's why even experienced sawyers will ask questions of other sawyers. You just never stop learning.


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