I am breaking bandsaw blades.

justallan1 · February 06, 2016, 08:43:27 PM

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 · February 06, 2016, 09:51:10 PM

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 · February 08, 2016, 10:55:25 AM

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 · February 08, 2016, 10:58:47 AM

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 · February 08, 2016, 11:17:18 AM

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

ladylake · February 08, 2016, 11:23:39 AM

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 · February 08, 2016, 11:32:16 AM

QuoteKeep 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)

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

Deese · February 08, 2016, 11:34:02 AM

Quote from: drobertson on February 08, 2016, 11:17:18 AM
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 · February 08, 2016, 07:14:59 PM

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 · February 08, 2016, 07:55:28 PM

Quote from: Deese on February 08, 2016, 10:55:25 AM
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 · February 08, 2016, 08:54:32 PM

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 · February 08, 2016, 09:08:45 PM

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 · February 08, 2016, 09:13:45 PM

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 · February 09, 2016, 06:21:19 AM

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 · February 09, 2016, 10:39:09 AM

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 · February 09, 2016, 12:43:02 PM

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 · February 09, 2016, 12:58:32 PM

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

Magicman · February 09, 2016, 01:10:25 PM

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 · February 09, 2016, 01:48:39 PM

kelLOGg · February 09, 2016, 08:25:34 PM

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 · February 09, 2016, 11:18:11 PM

Quote from: kelLOGg on February 09, 2016, 12:43:02 PM
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 · February 09, 2016, 11:38:24 PM

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 · February 09, 2016, 11:47:50 PM

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 · February 10, 2016, 12:19:05 AM

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 · February 10, 2016, 12:26:04 AM

Quote from: kelLOGg on February 09, 2016, 08:25:34 PM
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.