I've been following the Goodwill trip to Rusk, Texas, and rather than post on that thread thought I'd start a new one relative to bandsaw blade life between sharpenings.
MagicMan and company used 6 blades to saw almost 9000 bf of lumber (mostly pine, I think), which, if my arithmetic skills aren't one of the things I'm losing these days, comes to an average of about 1500 bf / blade. Wow!!
I've tried to find any other threads on the subject ... looks like there was one earlier this year, and 300-500 bf is maybe an average, which is about what I'm doing (if I don't hit something non-wood first, of course) sawing mostly hardwoods (oak, ash, walnut, hickory, ...)
But I'm wondering if there are any "secrets" to maximizing blade life? So far I've picked up:
- use the debarker if in any doubt
- power = speed, and the faster the better (less "bites" per cut) (so make sure you're always lugging the engine a little bit, regardless of power)
- Use the right blade for the lumber species (and maybe how dry it is??)
Other than that, I'm not sure I have any influence.
Relative to the last point (right blade for the job), I've gotta be honest that I haven't quite figured that one out yet. My simple mind would love to have a chart with species down the side, hp across the top, and populated with best blade to use. Or at least the basics (hook, gullet, etc). Maybe even green vs drier log. But maybe there are as many different opinions as there are FF members??
One other question ... I've never fatigued a blade, but WM (in their literature, at least) says to stop the blade after a cutting pass. Once I get cranking on a cant, that's the last thing I want to do. Is that the same with most folks? Is blade fatigue really a problem or does it get to the end-of-life for another reason?
Thanks for all your advice!
Pete
The first blade sawed over 2500 bf and would still curl your fingernail when I removed it. ;D Yes, the logs were clean but I still ran the debarker to help the blade. Not having to edge also vastly improved blade life.
During my normal sawing, I usually change the blade at lunchtime which could mean anything from 300 to 1000 bf depending upon the log cleanliness and the species being sawed.
I always disengage the clutch at the end of the cut and return with the engine idling.
That first blade was almost unbelievable, Lynn and I discussed several times the fact that we had not changed blades all day. I was constantly checking the knots to see if we had any wave from the blade dipping or rising in the cut, none found. The guys did assist the debarker with steel brushes as each log was loaded if a big spot of dirt was seen. We also discussed that using the edger could have prolonged the life of the blade. When edging on the mill it is almost impossible to use the debarker effectively due to the width of the flitches against the side supports. I cannot think of any time I have sawed that much with one blade either new or Resharp.
Using an edger will make a huge difference on blade life!
Not having to edge on the mill is the key!
When edging on the mill, you'll most likely cut some dirt when you cut through the stack of flitches!
I average between 6-800 board feet between blade changes and once in a while I'll get 1,000 bf on a blade.
Overall blade life (with the exception of hitting metal, rocks, etc) is based on the number of rotations the blade makes over the wheels!
A blade, like a piece of wire will only bend so many times before it breaks.
I alway disengage the blade when I exit the far end of the log or cant!
Milling is a double edged sword.
An edger has baldes. So extending the life of a mill blade leads to dulling of edger blades.
When you saw through a log and disengage your blade, it just adds wear to your clutch and clutch belt.
I may turn the blade off while undressing a log....but after my cant is ready to be sawn into boards....I never disengage the blade. Just saw through.....come back......lower .......and go again. :)
The total blades actually used sawing was one less because of a brain fart when I tried to back out of a cut with a new blade. :-\
1500bdft is an outstanding average, in any case, with any blade. I stop my blade when turning or any other stoppage is needed, but when sawing down a cant, 4-6 boards is about all I want to raise the head so I will stop and remove, then flip and restart. Log cleanliness is paramount for blade longevity, clean means sharp, sharp means less heat and stress. david
What blades were being used?
WM 10° DoubleHard.
Quote from: Magicman on December 14, 2013, 02:10:58 PM
The total blades actually used sawing was one less because of a brain fart when I tried to back out of a cut with a new blade. :-\
Aren't you allowed one brain fart in 4 long days of sawing? Still a pretty good lumber/brain fart ratio. ;D
Quote from: SawyerBrown on December 14, 2013, 02:39:31 PMAren't you allowed one brain fart in 4 long days of sawing?
Hopefully yes, because they were long days. We were sawing at 7:30, a half hour for lunch, and quitting time at 5:30. That makes it very easy to make a mistake.
As another data point as to whether to disengage the saw after each cut, I went back and looked at WM's sales / demo videos (and even the Shootout video). Very hard to tell on the LT40 video, but on the LT35 video I'm sure I see sawdust flying on the return pass at one point (saw is barely above the cant).
My biggest concern is wear and tear on drive belt and/or brake. For those that do disengage, has that been a problem? For those that don't, are you breaking blades due to fatigue? Might be an argument either way as far as fuel savings, first impression is to idle her down, but re-accelerating those two pulleys burns some fuel too.
Quote from: Magicman /quote]
We were sawing at 7:30, a half hour for lunch, and quitting time at 5:30. That makes it very easy to make a mistake.
MM, so glad that everyone got home safe and sound. Whatever the job, when fatigue sets in, we tend to lose focus / get sloppy, and that's when accidents happen. Hopefully it's just a bent blade and not something more serious. There were not one, but two, farmers killed this fall in the very small town I grew up in here in Illinois. Both involved combines -- one got snagged in the rotating reel (while his young son sat helplessly in the buddy seat in the cab), the other got crushed under a header that wasn't properly supported.
Really has nothing to do with this thread, I just hope and pray we're all seasoned enough to admit that, when it's time to quit, it's time to quit! Especially when heavy machinery, and in our case heavy raw materials, are involved. (And I'm saying this to remind myself more than anything else)
Quote from: SawyerBrown on December 14, 2013, 04:06:12 PM
As another data point as to whether to disengage the saw after each cut, I went back and looked at WM's sales / demo videos (and even the Shootout video). Very hard to tell on the LT40 video, but on the LT35 video I'm sure I see sawdust flying on the return pass at one point (saw is barely above the cant).
My biggest concern is wear and tear on drive belt and/or brake. For those that do disengage, has that been a problem? For those that don't, are you breaking blades due to fatigue? Might be an argument either way as far as fuel savings, first impression is to idle her down, but re-accelerating those two pulleys burns some fuel too.
This is what I'm talking about.....disengaging the blade every dog gone time you get to the end of the log has got to take its toll on brakes, belts, the switch or clutch handle and other things as well.
I engage and leave it on unless I need to walk in front of the blade for a reason and then I turn it off.
Once a blade is moving....it is Happy, Happy, Happy......but once you start engaging and disengaging......there has got to be some kind of "jerk" to get that blade moving know matter how small the jerk is. To me engaging and disengaging to many times will shorten the life when it comes to breaking.
Sawyerbrown, I didn't think that us ole farts had to worry about fatigue until 95 or so. bg
Magicmans mill has the auto clutch. I listened and watched the engagement many times in 4 days of sawing and it seemed smooth with no belt squealing or jerking. Brake may wear but you got to give some and take some somewhere. bg
bg, if you're still sawing at 95, you're a better man than me! I plan to be sawing logs of a different sort by that time :D
I have been wondering about that stopping and starting, Im not convinced either way. The brake and clutch and belts are disposable. I have not changed my belt in 1.5 years. I will change it for next season as I think I am at the end of adjustment. The last saw job I had slippage in the afternoon. I would think it is better to save the life of the blade, at 30+$ a blade and such a short life, I will try to stop and start more next season.
This discussion will be interesting to watch and read. See what everyone else does.
Quote from: Bill Gaiche on December 14, 2013, 04:53:08 PM
Magicmans mill has the auto clutch. I listened and watched the engagement many times in 4 days of sawing and it seemed smooth with no belt squealing or jerking. bg
If the engine is turning and the saw is not, the belts are the only thing in the system that can "absorb" the difference. I can't remember on my mill what comes first, engine speed or pulley engagement (what happens when), or more or less simultaneously, but I wonder if the auto clutch doesn't do a better job of first getting the belts engaged and then the engine accelerating the whole system. I do recall that if I try to engage too quickly, I do get a little belt chirp, so in general a little slower is better; but it's hard to not get at least a little chirp.
Quote from: Bill Gaiche on December 14, 2013, 04:53:08 PM
Brake may wear but you got to give some and take some somewhere. bg
Good point Bill. If you have the proper tension on your belt, you should hear a little "squeal" when you engage your blade.
I have completed 12 years of sawing and I am on my second drive belt and second brake pad. I am sure that WM lets it run during shootouts, etc. but their operator's manual says to disengage and that is the way I learned to saw.
I also might contact the cant/log end or a high knot when returning. If the blade was running, that would be a blade.
Our individual sawing routine is what each of us is comfortable with. That is good enough for me. :)
Quote from: Magicman on December 14, 2013, 05:22:21 PM
Our individual sawing routine is what each of us is comfortable with. That is good enough for me. :)
Well said Magic....does this mean I can continue doing it MY WAY? Its always a SHOOT OUT around my mill. :D :D :D
I'm not sure on others practices, but, I have never had an issue with stopping and starting. the brake is still good, and the drive belt as well. As we know the saw bands, belts and brakes are parts designed for wear, and should be expected. I will say, I have ran the .042 blades longer than the .045's per change. This is on my mill and the way I run it. There are so many factors that come into play that one can only experiment with different blades to find the one that fits the need. All said, the job done in Texas by MM was a good example of perfect rhythm, clean logs, and timing of all the above which includes good alignment. More could be said, but I'll leave it at this. I always hear a lil squeal when engaging, david
Quote from: Magicman on December 14, 2013, 05:22:21 PM
I have completed 12 years of sawing and I am on my second drive belt and second brake pad.
MM, I'm still trying to learn (and not yet set in my ways ;D)), and your data is pretty compelling. I think I'll give it a shot and see if it doesn't slow me down too much.
But I won't hold it against you other fellers to keep doing it like you are!!
Quote from: Magicman on December 14, 2013, 02:59:46 PM
Quote from: SawyerBrown on December 14, 2013, 02:39:31 PMAren't you allowed one brain fart in 4 long days of sawing?
Hopefully yes, because they were long days. We were sawing at 7:30, a half hour for lunch, and quitting time at 5:30. That makes it very easy to make a mistake.
That is a very long day of working. My preference would be to start late and quit early. 8)
Quote from: Holmes on December 14, 2013, 06:16:30 PM
My preference would be to start late and quit early. 8)
You need an Off Bearer Holmes? :)
Even with mostly milling 2x material, 1,500 bf/blade is pretty impressive.
I'm thinking there was a little Divine Intervention going on there. smiley_angel02_wings
Quote from: SawyerBrown on December 14, 2013, 04:06:12 PM
As another data point as to whether to disengage the saw after each cut, I went back and looked at WM's sales / demo videos (and even the Shootout video). Very hard to tell on the LT40 video, but on the LT35 video I'm sure I see sawdust flying on the return pass at one point (saw is barely above the cant).
My biggest concern is wear and tear on drive belt and/or brake. For those that do disengage, has that been a problem? For those that don't, are you breaking blades due to fatigue? Might be an argument either way as far as fuel savings, first impression is to idle her down, but re-accelerating those two pulleys burns some fuel too.
I thought it said in my owner/operator manual to disengage upon exiting the far end of the cant or log!
I looked through the setup and operation section and step 4 says to disengage the blade when you exit the log.
Step 5 says "Always disengage the blade before returning the carriage for the next cut"!
I haven't noticed any ill effects by continually starting and stopping through the course of sawing for the day!
Since I've had my mill, I've only replaced the drive belt twice and I've sawn over 350,000 board feet.
I think a drive band that is slipping under load will wear out much faster than it will from engaging-disengaging the clutch.
David, not sure about that "squeal" thing. I think that's telling you that the belt is about worn out.
On my LT30, I disengage only when I have to, as on that older mill, it'll flat wear a guy out tipping that motor back and forth.
My mill has always squealed on engagement. Mr. Tom told me it was normal.
Quote from: Delawhere Jack on December 14, 2013, 07:31:26 PM
David, not sure about that "squeal" thing. I think that's telling you that the belt is about worn out.
Nah.....a little sqauk is just right. If you get the belt to tight...that sucker will squeal like a stuck hog and not long after that you will lose a shaft. smiley_crying
Quote from: POSTONLT40HD on December 14, 2013, 07:41:01 PM
Quote from: Delawhere Jack on December 14, 2013, 07:31:26 PM
David, not sure about that "squeal" thing. I think that's telling you that the belt is about worn out.
Nah.....a little sqauk is just right. If you get the belt to tight...that sucker will squeal like a stuck hog and not long after that you will lose a shaft. smiley_crying
The belts on the mills have specific belt tensions that they are to be adjusted to, and if the drive belt/s adjusted properly you should get a definate chirp when engaging the blade!
Quote from: Jeff on December 14, 2013, 07:33:39 PM
On my LT30, I disengage only when I have to, as on that older mill, it'll flat wear a guy out tipping that motor back and forth.
My mill has always squealed on engagement. Mr. Tom told me it was normal.
Engaging and disengaging the blade all day will definately take it's toll on ones shoulder.
I've found that when I engage the blade on my mill, that I will straighten my arm, then just lean back a little, it's easier on the shoulder!
This is exactly why the autoclutch was invented.
In the beginning, I was told that starting and stopping the band caused a lot of stress to the whole works, including the band, so I would keep it running for multiple cuts. Then I was told to stop the band as soon as I exited the cut to save on flex life. This was all from WM. Now, if I can make a few cuts in thinner boards, I leave it running. I have AutoClutch, so it's not a shoulder issue, although I can certainly see where that would really be a concern without AutoClutch.
Yup, a chirp is correct. I was told, again by WM, that it was better to chirp the belt than to slip it.
I have a centrifugal clutch on my mill. My shoulder could not take the off and on part. That is my big issue.
Quote from: thecfarm on December 14, 2013, 09:13:22 PM
I have a centrifugal clutch on my mill. My shoulder could not take the off and on part. That is my big issue.
This is my point y'all.....if a shoulder can't take it.......it's just a matter of time before machine parts start breaking down. This is why I keep mine running.
Mine runs a lot also but I idle the engine down when needed. I'm with Poston with this one, I think it's hard on everything clutching it in and out. Even just speeding up the 27hp Kohler sounded tough on it , a little faster idle helps. My little diesel doesn't mind speedind up-down. Steve
The WM manual for the LT70 section 4.11 "Optimal Cutting Procedure" states "In order to achieve maximum production rates, it may be desirable to leave the blade engaged when returning the carriage"
We gained at least 10% in production when we started leaving the blade engaged. We are getting more bd/ft sawn per blade than we were when stopping the blade exiting the cut. The only negative change we have noticed is that we burn an additional gallon or more in diesel than we did before but with the added production our fuel per bd/ft sawn has remained about the same.
We do have the out-feed conveyor and DCS operator controls in a saw cab so nobody is ever close to the running blade. Occasionally we ruin a blade knocking it off with a splinter or something on the drag-back that wouldn't have been damaged if the blade were stopped.
I made the change after watching a video of the mill running. If you haven't seen a video of yourself sawing its a real eye-opener. Take one and put a stopwatch on the time your loosing engaging and disengaging the blade, positioning the head or punching buttons on the set-works. We gained quite a bit of production by doing whatever we could to prepare for the next cut while the saw-head is moving. This included advancing the next log on the deck, changing modes or sets on the set-works, and leaving the blade running. We try to keep the head in motion as much as we possibly can.
On shorter logs there sure isn't time to disengage the blade or slow down the engine. Steve
I do the same thing, to keep the blade going on 8' 10' logs . I call it the Wood Mizer rock. Back and forth never stopping . When I come out of the log I'm going up till I think I'll miss the cant then back I go hit the down lever before I clear the cant, go forward and hit the cant with the blade just in the nick of time to when the blade is set, sometimes I go in the cant and the blade has to go down an 1/8 to set. :D :D :D but I don't do that too much ;D
And that is a lot of BF for a blade. Good job in prepping the logs
MM can call that the "Loaves and fishes blade" ;) The manual for my LT40 super says to leave the blade engaged if so desired. I often do, especially once I get to a cant and start slinging boards. I have also ruined more than a few blades when my dragback misses a slab and I hit it with the blade- ka-pow!