I am breaking bandsaw blades.

[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?

[sandsawmill14]

look at the blades good and see if it is in the weld first thing

[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. 

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.

[Deese]

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. 

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.

[Deese]

I will not be a happy camper if they are faulty blades.

[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.

[Deese]

I feel that it is something on my end.

[Deese]

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.

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.

[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

[Deese]

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

[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

[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

[Dave Shepard]

That sounds strange to me. I've never had one break in the weld.

[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

[dgdrls]

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]

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 am not following this completely, but you have some blade guide issues that need correcting. 

[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.

[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

[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.

[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

[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.

[Chuck White]

  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!

[Nomad]

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.

[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.

[justallan1]

I'd definitely agree with the blade riding against the flange of the blade guide.
I have the same mill and on mine the adjustable blade guide arm is held by a "T" handle that sits at 45 degrees pushing the guide arm down and forward, so the adjustable arm is at all of the same spots except how close it is to your log.
If it were me I'd start with checking your belts, then get the wheels true and then get your guides where you want them.
As for the tensioner, if you go by the gauge on the mill it would definitely feel like you are going to snap blades while tightening them. I haven't had a problem, but I go by how much I can move the blade by hand also and it seems to work.

[Ox]

Probably taking an hour or two and doing a complete, thorough and completely anal retentive alignment and tune up starting from square one would do wonders.  Sometimes things wear and move around a bit and all of these little things out of adjustment add up to a big problem.  Ever hear of tolerance buildup?  I hope you get your mill back in fighting shape soon.

[Deese]

Thanks again for all of the help. All of you guys have really helped me with this. Yes, when I adjusted the tracking on one wheel, it did position the blade closer to the blade guide, which caused the blade to come into contact with the flange when sawing. I remember seeing a spark when the blade first entered the log. That was the blade contacting the flange. I noticed wear/scratches on the back of the band where the contact was made. Here are a few pics to help illustrate...

Here, you can see how close the blade was to the flange. The blade would contact the flange when sawing and the roller guide would get quite warm from the friction (the blade too). I have since readjusted this guide and surprisingly it did move back just a tad further...I sawed a cedar yesterday and the blade did not come into contact with the flange after adjustment.



 

Her is another pic of the same guide...My belts sometimes get some sawdust buildup on them. Could this be a big issue regarding blade wear?



 

Here is a picture of the other blade guide setup. I haven't had time to try adjusting this one yet.



 

This is after I adjusted the tracking. Before, the blade was riding closer to the front of the wheel.



 


 

[Deese]

I plan on doing a little more sawing this evening. We shall see how it goes. You fellas have been a great help. Would sawdust buildup on the belts contribute to premature blade wear/breakage?

[drobertson]

I don't think so on the build up, I get it as well, with only the occasional breakage due to fatigue,

[ladylake]

  Keep in mind if you are running blades that have been on the mill already  they most likely have been damaged .  Best to run new blades after doing adjusting so you know for sure if the problem is fixed. Steve

[Deese]

Keep in mind if you are running blades that have been on the mill already  they most likely have been damaged .  Best to run new blades after doing adjusting so you know for sure if the problem is fixed. Steve

Yes Sir and thank you for taking the time to help me with your statement below. You guys are the best.  8)

  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

[Deese]

I don't think so on the build up, I get it as well, with only the occasional breakage due to fatigue,

That's good to know. I'm sure the buildup doesn't help any, but at least it's not a deal breaker. I do need to adjust the blade wipers down further. At this point they aren't doing very much.

[Ox]

I was just going to suggest the blade wiper/sawdust deflector.  My mill is set up to where the blade isn't touching the guide flanges freewheeling but in the cut they're touching slightly.  About 3/16" away from the flange.  I don't run anywhere near the recommended tension on the blade, which is 2500 lbs.  I run between 1800 or 1900 when using the flutter test.  Sharp blades always cut well at this tension and I'm helping the life of my bearings as well.  Glad to hear you got your mill back in shape - you'll be happy(er) from hear out!

[kelLOGg]

Here, you can see how close the blade was to the flange. The blade would contact the flange when sawing and the roller guide would get quite warm from the friction (the blade too). I have since readjusted this guide and surprisingly it did move back just a tad further...I sawed a cedar yesterday and the blade did not come into contact with the flange after adjustment.


 

Am I missing the context here?
If the blade does not contact the flange during sawing then why is there a flange at all?
I adjust my roller guides so that I have the angled gap when the band is idling or not sawing. When the blade enters the log, force on the band pushes it back and contacts the flange; that's what supports the band during the cut. I set my band wheel tracking so that when the band is pushed back the teeth never ride on the wheels.
Bob

[Deese]

Brother I sure don't know. That is why I posted this thread to begin with. My thinking (which is a scary thought) is if tracking is adjusted properly, my blade should only come into contact with the flange when encountering irregularities in the density of wood, such as a knot. So, if it hits the flange during log entry or a bad knot, it's okay as long as it recovers by losing contact. I know that the blade is dull whenever the blade is unpredictability contacting the flange. Maybe I'm wrong, but with my particular mill, I'm thinking constant blade contact with the flange is a sure sign of a dull blade?

[sandsawmill14]

i dont know know either ??? there are so many setups and opinions on guides/down pressure that is is certain that there is not one that fits every mill. mills with flat guides instead of roller guides have zero down pressure and the band runs in constant contact with the roller bearing that keeps blade from pushing off the band wheels. it works perfectly the only advantage to the roller guides that i can see is that they last alot longer that the flat guides. that is what my hudson mill has and it has sawn alot of lumber. on the timberking b20 i run zero down pressure on the roller guides but the blade stays about 1/8" from the flange when in the cut. all of the help on here is great to get you real close but you will have to fine tune it to suit you on your on  ;)

[Kbeitz]

I set my tracking with the guide wheels off the machine.
When I get it right then I put them back on and adjust so they almost touch
the flange and a little down pressure. Works for me.

[ladylake]

 With the flange set 1/4" back the blade will only contact the flange when it is dull or pushing real hard. As I've mentioned every time my mill get out of adjustment and the flange get too close to the back of the blade they start breaking fast. My theory is that when the back of the blade hits the flange too hard the blade flexes around the flange putting a lot of stress in the gullet.  Running 1/4" down pressure my mill saws straighter , really no down side to running 1/4 down pressure.   Steve

[Deese]

Thanks again friends for the input. I think I will be in good shape when I tinker with it a little more this weekend.

[kelLOGg]

I ran this question about the back of the band contacting the flange by Cooks Saw and Ladylake is exactly RIGHT!
Has anyone actually observed the underside of the blade while sawing to confirm that there is no contact? I haven't - I just assumed there is contact for support. Without mirrors that would be dangerous.

[Deese]

I totally understand about the flange being 1/4" back from the blade, but I don't think I understand about down pressure?

[Magicman]

The blade guides being ¼" lower than the bandwheels puts the blade guides in control of the blade, not the bandwheels.  Maybe that is why they are called "blade guides".   ;D

[Deese]

 

[kelLOGg]

I also learned form James at Cooks Saw that if the band back does contact the flange too long the flange will overheat and turn blue. I wouldn't have guessed non-contact is built into the design. I guess my Personal Text is aptly chosen. ;)

[sandsawmill14]

I ran this question about the back of the band contacting the flange by Cooks Saw and Ladylake is exactly RIGHT!
Has anyone actually observed the underside of the blade while sawing to confirm that there is no contact? I haven't - I just assumed there is contact for support. Without mirrors that would be dangerous.

you can tell by the back of the band if it is making enough contact to hurt the band.  just to be clear my blades DO NOT touch the back of guide rollers on either the s&w or the timberking. the hudson has flat guides with a roller bearing that runs against the back of band and is designed to run with 0 down pressure on blade. the down pressure is why i mentioned it referring to different setups. i dont think anyone would argue that you could saw with constant pressure against flange on guide rollers

[redbeard]

Sandsawmill14 Iam Curious about the Hudson guides do they hold up as long as roller guides. I see that most resaw mills use the same set up.

[sandsawmill14]

i never kept up with footage to know how many bf per set of them but when i was running full time i would have to change 2-3 times a year. the best thing about them is they are 1" x 1" square and 1/4 thick so i just made my own replacements  ;D   a 4' piece of 1/4 x 1 flatstock and you got a lifetime supply :D :D :D

[Tom the Sawyer]

I think the term "down pressure" is confusing.  There isn't any more pressure between the guides than there is on the remainder of the band.  My guide rollers are set at 1/4" below the wheel tangent.  If the band, under tension but with the guide wheels retracted away from the band, is a certain distance above the bed, the guide wheels are positioned to hold the blade (under tension), between the guide rollers, 1/4" closer to the bed.  The tension remains the same as you would normally use.  The guide rollers also provide a fine adjustment for keeping the blade flat laterally and longitudinally.

When I sharpen chisels or a plane iron, I have a general bevel, and then I hone a "micro bevel" on the very tip.  Perhaps a better description would be adjusting the guide rollers to "micro align" the blade. 

[YellowHammer]

I also learned form James at Cooks Saw that if the band back does contact the flange too long the flange will overheat and turn blue. I wouldn't have guessed non-contact is built into the design. I guess my Personal Text is aptly chosen. ;)

On my WM, I can clearly hear the change in pitch of the saw blade's "hiss" when I'm sawing hard enough to be hitting the back shoulder of the blade guide, which is something to be avoided.  It's just one more good indication of when it's time to change out a dull band.  Cracks in the back of the band are a good indicator of staying too much on the shoulder.  Gullet cracks get ground out every band sharpening, but back cracks just get worse.  Lots of times you can also hear the crack as it goes around, causing a rympthmic "shick" sound.  It's a "dead band walking" when you hear that, she's gonna blow. 

[sandsawmill14]

very good description tom

[Deese]

Lots of times you can also hear the crack as it goes around, causing a rympthmic "shick" sound.  It's a "dead band walking" when you hear that, she's gonna blow. 

Exactly.

[Deese]

Lots of times you can also hear the crack as it goes around, causing a rympthmic "shick" sound.  It's a "dead band walking" when you hear that, she's gonna blow.

If I hear the band breaking, I just keep on sawing until it breaks. Just like you said, there's no turning back once you hear that familiar sound.

[Chuck White]

If I hear a cracked blade, it comes off the mill immediately, no need to mess up the B-57's, or wasting time fishing the broken band out of who knows where.

Just sayin'.

[Ox]

Me too.  I hear the clicking, time's a ticking and I'm not gonna be pickin'..........
the blade out of my mill when it breaks.