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I am breaking bandsaw blades.

Started by Deese, February 05, 2016, 03:58:11 PM

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Deese

Friends, I have a slight problem and need your help.

I am breaking bandsaw blades. I ordered a new box of blades and have broken 2 blades out of 5 thus far. Surely it's something to do with my mill and not the blades. I have only been cutting really soft wood. Bald Cypress. If I'm lucky I will get 300bf from a new blade and then I'm afraid it's going to break, so I change the blade. If I keep sawing without changing, I will begin to feel a somewhat "pulsing" vibration from the mill and can hear it too. It's really more of a sound than a feeling...Hmm, not sure how to explain it. Anyways, it's a distinct sound and feeling that only the operator would notice. 

I know that I am guilty of one thing, and that is not FULLY extending the adjustable blade guide up next to the cant while sawing. If I extend the blade guide out too far, it comes into contact with the blade in a way that causes it to dive every time (I need to adjust the guide). The problem is that the bar holding the guide has a lot of "play" in it whenever you extend or retract it. You simply slide the bar in or out, then tighten it with a screw to secure it. So, I pretty much leave it in the same position unless I need to retract it for larger cants. In other words, I generally keep it in this "sweet spot" while sawing and have never had much trouble... The guide, on average, was about 8"-1 foot away from the cant when sawing. So, the lack of support on the back of the blade could be causing the premature breakage, right?

I previously had an issue with the mill throwing the blade (even when not using diesel for lube). I noticed that the blade was riding too far on the front of the belted free-spinning wheel. So, I adjusted the wheel so that more surface area of the band was in contact with the belt, but not so much that it would remove the set from the teeth.

One other thing...Could I be applying too much tension on the blade? I tighten it down pretty good, but I seriously doubt this is the cause...I need to call EZ and ask about proper blade tension on this mill. I just tighten it down and start sawing.

A. Not fully extending the adjustable blade guide?
B. Mill not aligned properly?
C. Too much blade tension?

Maybe all or some of the above?




2004 LT40 Super 51hp w/6' bed extension
Cooks AE4P Edger
Cat Claw sharpener/Dual Tooth Setter
Kubota svl75-2 skidsteer w/grapple, forks, brushcutter
1977 Log Hog Knuckleboom loader/truck

sandsawmill14

look at the blades good and see if it is in the weld first thing :)
hudson 228, lucky knuckleboom,stihl 038 064 441 magnum

YellowHammer

Typically the pulsing you feel is when a crack has started in the band and its going around contacting the rollers or the wood; you can feel and hear it.  That's the sound of a band dying, it's just a matter of time. 

Quote from: sandsawmill14 on February 05, 2016, 04:07:41 PM
look at the blades good and see if it is in the weld first thing :)

It's important to do a careful inspection and see where the crack is starting, such as the weld, the gullet, or the back of the band.  Each one will mean a different failure scenario.
YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

Deese

Quote from: YellowHammer on February 05, 2016, 04:13:41 PM
Typically the pulsing you feel is when a crack has started in the band and its going around contacting the rollers or the wood; you can feel and hear it.  That's the sound of a band dying, it's just a matter of time. 

Quote from: sandsawmill14 on February 05, 2016, 04:07:41 PM
look at the blades good and see if it is in the weld first thing :)

It's important to do a carful inspection and see where the crack is starting, such as the weld, the gullet, or the back of the band.  Each one will mean a different failure scenario.

Thanks fellas. I remember looking at the first one and it was in the gullet. BUT I will inspect both of them when I get home from work.
2004 LT40 Super 51hp w/6' bed extension
Cooks AE4P Edger
Cat Claw sharpener/Dual Tooth Setter
Kubota svl75-2 skidsteer w/grapple, forks, brushcutter
1977 Log Hog Knuckleboom loader/truck

Deese

I will not be a happy camper if they are faulty blades.
2004 LT40 Super 51hp w/6' bed extension
Cooks AE4P Edger
Cat Claw sharpener/Dual Tooth Setter
Kubota svl75-2 skidsteer w/grapple, forks, brushcutter
1977 Log Hog Knuckleboom loader/truck

Jeff

I would rather it be faulty blades if it were me, because then, you know your mill is alright, and you can usually get replacements if it is clearly faulty blades. Odds are though, it's not.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Deese

I feel that it is something on my end.
2004 LT40 Super 51hp w/6' bed extension
Cooks AE4P Edger
Cat Claw sharpener/Dual Tooth Setter
Kubota svl75-2 skidsteer w/grapple, forks, brushcutter
1977 Log Hog Knuckleboom loader/truck

Deese

QuoteIt's important to do a carful inspection and see where the crack is starting, such as the weld, the gullet, or the back of the band.  Each one will mean a different failure scenario.

YH-- I overlooked this statement earlier. Yes sir I will be sure to remove the band immediately the next time I hear/feel that familiar vibration and hopefully we can figure this thing out. I finished sawing my small whack of logs yesterday and it will probably be a week before more are delivered.
2004 LT40 Super 51hp w/6' bed extension
Cooks AE4P Edger
Cat Claw sharpener/Dual Tooth Setter
Kubota svl75-2 skidsteer w/grapple, forks, brushcutter
1977 Log Hog Knuckleboom loader/truck

kelLOGg

When my breakage rate went up I lessened the tension to the point of onset of flutter and the break rate dropped significantly. (I learned that on the FF)
Bob
Cook's MP-32, 20HP, 20' (modified w/ power feed, up/down, loader/turner)
DH kiln, CatClaw setter and sharpener, tandem trailer, log arch, tractor, thumb tacks

Deese

Quote from: kelLOGg on February 05, 2016, 05:09:18 PM
When my breakage rate went up I lessened the tension to the point of onset of flutter and the break rate dropped significantly. (I learned that on the FF)
Bob

Thank you sir for the comment. I am thinking (hoping) that my issue is simply something I am doing incorrectly. I do feel that I am putting too much tension on the band. I mean, I REALLY tighten that sucker down. Plus, the full body of the band wasn't riding on the belt...just the back of the band. That much tension on such a small portion of the body of the band, plus the lack of support from the adjustable blade guide are probably all contributing factors...I may be totally wrong but at least it sounds good  :D ;D  But I really don't know smiley_confused smiley_whacko
2004 LT40 Super 51hp w/6' bed extension
Cooks AE4P Edger
Cat Claw sharpener/Dual Tooth Setter
Kubota svl75-2 skidsteer w/grapple, forks, brushcutter
1977 Log Hog Knuckleboom loader/truck

Wayniac

dont rule out bad blades i got one order of blades that was so brittle i guess thats what you call it that the teeth broke off when trying to put a set in them didnt have much luck sawing with them but didnt figure i could ever prove it were do you get your blades from
wayniac

sandsawmill14

i had 2 blades break in the weld this week its not all that uncommon but they will make good on them with no questions ask. i will get 15-20 a year that break in the weld but that is not bad for as many blades as i buy :)
hudson 228, lucky knuckleboom,stihl 038 064 441 magnum

Dave Shepard

That sounds strange to me. I've never had one break in the weld.
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

sandsawmill14

i use the woodmizer silvertip 1 1/4 .042 blades and i am on autoship with mill supply so i get 10 every week i started that last march i think it was  ???  so that 15-20 blades that broke in the weld is out of somewhere between 350-400 blades so its still a small percentage :)  i can go back and check records to get an exact number if anyone thinks its needed :)
hudson 228, lucky knuckleboom,stihl 038 064 441 magnum

dgdrls

Quote from: Deese on February 05, 2016, 05:38:28 PM
Quote from: kelLOGg on February 05, 2016, 05:09:18 PM
When my breakage rate went up I lessened the tension to the point of onset of flutter and the break rate dropped significantly. (I learned that on the FF)
Bob

Thank you sir for the comment. I am thinking (hoping) that my issue is simply something I am doing incorrectly. I do feel that I am putting too much tension on the band. I mean, I REALLY tighten that sucker down. Plus, the full body of the band wasn't riding on the belt...just the back of the band. That much tension on such a small portion of the body of the band, plus the lack of support from the adjustable blade guide are probably all contributing factors...I may be totally wrong but at least it sounds good  :D ;D  But I really don't know smiley_confused smiley_whacko

There is no reason to "..REALLY tighten that sucker down"   

http://www.cookssaw.com/index.php/sawmill-blade-insight/troubleshooting-blade-breakage
really good info here,

Dan

Magicman

Quote from: Deese on February 05, 2016, 03:58:11 PMIf I extend the blade guide out too far, it comes into contact with the blade in a way that causes it to dive every time (I need to adjust the guide). The problem is that the bar holding the guide has a lot of "play" in it whenever you extend or retract it. You simply slide the bar in or out, then tighten it with a screw to secure it. So, I pretty much leave it in the same position unless I need to retract it for larger cants. In other words, I generally keep it in this "sweet spot" while sawing and have never had much trouble... The guide, on average, was about 8"-1 foot away from the cant when sawing. So, the lack of support on the back of the blade could be causing the premature breakage, right?
I am not following this completely, but you have some blade guide issues that need correcting. 
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

pine

I have had several welds break lately as well.  Not sure what is going on for that to happen.

losttheplot

Check the gap between the back of the blade and the guide roller flange is to spec.
DON'T BELIEVE EVERYTHING YOU THINK !

ladylake

  Yes the gap between the back of the blade and flange is real important, if my mill get out of adjustment and it gets close blades start breaking fast, I run mine 1/4" back as Cooks recommends with real good results. From your post it sound like you might have it to close, check it with the movable guide all the way and all the way in and make sure it about 1/4"  back. The next big blade breaker is worn v belts, if the blade touches the metal on the wheel they will break fast also. In all of these years I've had at the most 5 blades freak in the weld.  If everything checks out you could just have a bad batch of blades.  Steve
Timberking B20  18000  hours +  Case75xt grapple + forks+8" snow bucket + dirt bucket   770 Oliver   Lots(too many) of chainsaws, Like the Echo saws and the Stihl and Husky     W5  Case loader   1  trailers  Wright sharpener     Suffolk  setter Volvo MCT125c skid loader

terrifictimbersllc

The roller needs to be tilted slightly, horizontally, so that if the back of the blade contacts the flange, it does so on the side of the roller that is spinning up, not the side of the roller that is spinning down.   Correctly tilted, the blade is pushed against the roller if it contacts the flange, incorrectly tilted, it is pushed away from the roller as it contacts the flange.

Your blade guide arm needs to be adjusted in its mounts so that 1) it does not move except in or out as it is supposed to and 2) so that as it moves in or out, the same spacing (which on my LT40 super 2001 is 1/8") is maintained.

I don't know what's in your manual, but in my manual all the instructions are there to align the mill properly.
DJ Hoover, Terrific Timbers LLC,  Mystic CT Woodmizer Million Board Foot Club member. 2019 LT70 Super Wide 55 Yanmar,  LogRite fetching arch, WM BMS250 sharpener/BMT250 setter.  2001 F350 7.3L PSD 6 spd manual ZF 4x4 Crew Cab Long Bed

Deese

Thanks fellas for all of the tips. Based on what you guys have said, I believe I have discovered the problem without even going to look. I will try to take some photos sometime over the weekend to help illustrate my delimma. Basically it's a blade guide issue with the stationary roller guide. The problem is this guide is already adjusted as far back as it can go, but needs to go back a little farther. To be continued. ..Again, the advice is greatly appreciated
2004 LT40 Super 51hp w/6' bed extension
Cooks AE4P Edger
Cat Claw sharpener/Dual Tooth Setter
Kubota svl75-2 skidsteer w/grapple, forks, brushcutter
1977 Log Hog Knuckleboom loader/truck

Kbeitz

One more thing to check. Your band saw wheels or tires could be out of round causing the pulsing.
That would put a lot of tension on your blade.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

Chuck White

Quote from: ladylake on February 06, 2016, 09:02:11 AM
  Yes the gap between the back of the blade and flange is real important, if my mill get out of adjustment and it gets close blades start breaking fast, I run mine 1/4" back as Cooks recommends with real good results. From your post it sound like you might have it to close, check it with the movable guide all the way and all the way in and make sure it about 1/4"  back. The next big blade breaker is worn v belts, if the blade touches the metal on the wheel they will break fast also. In all of these years I've had at the most 5 blades freak in the weld.  If everything checks out you could just have a bad batch of blades.  Steve

I absolutely agree with Steve.

If your blade belts are worn to the point where the blade touches the wheel, the blades won't last very long.

If this is the case, you should be able to see shiny contact marks on the blades!
~Chuck~  Cooks Cat Claw sharpener and single tooth setter.  2018 Chevy Silverado and 2021 Subaru Ascent.
With basic mechanical skills and the ability to read you can maintain a Woodmizer  LT40!

Nomad

Quote from: Deese on February 06, 2016, 10:15:39 AM
Thanks fellas for all of the tips. Based on what you guys have said, I believe I have discovered the problem without even going to look. I will try to take some photos sometime over the weekend to help illustrate my delimma. Basically it's a blade guide issue with the stationary roller guide. The problem is this guide is already adjusted as far back as it can go, but needs to go back a little farther. To be continued. ..Again, the advice is greatly appreciated

     From what you're saying , are you sure your blades are tracking properly on the wheels?  If tracking too far back, it could cause this.  Another option is that something is bent.  Just guessing here.
Buying a hammer doesn't make you a carpenter
WoodMizer LT50HDD51-WR
Lucas DSM23-19

customsawyer

I agree with Nomad. I think when you adjusted your tracking on the one wheel it moved the blade back against the flange of the blade guide.
Two LT70s, Nyle L200 kiln, 4 head Pinheiro planer, 30" double surface Cantek planer, Lucas dedicated slabber, Slabmizer, and enough rolling stock and chainsaws to keep it all running.
www.thecustomsawyer.com

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