New guy, all in

[learninfast]

    Hello everyone, this is my first time here and it looks like this place has some real knowledgeable folks around.  Let me start by saying up until a few months ago I had never run a band saw, or really anything bigger than a table saw.  I am a carpenter by trade.  Doing mainly conventional  framing and siding.  With work slowing in my area I had to broaden my scope a little and picked up a jobs as head sawyer for a company that does timber frame truss work and log accent work. 

    The sawyer that had been working for them had about five years experience, but I only got one week to train under him before he left.  I pretty much got the here's the mill, here's the go button, giver all she's got, no faster, faster.  The last sawyer, being the only one who really new how the mill worked, is now gone.  Things went fine for a week or so, until the old girl started to act up on me.

   The mill is a Mighty Mite mark IVb, which is the largest band saw that mighty mite make.  I have the whole sharpening and kerf setting setup(so I'm learning about blade maintenance at the same time).  It is a very impressive piece of machinery and can make some beautiful guts when properly tuned.  However it is about three years old now, with an estimated 3000hrs, and has seen little to no maintenance.  Besides having a new sawyer running it : some things seem worn and are starting to effect it's performance.  I kinda get the feeling that the last guy was just pushing it REALLY SLOW in order to maintain a decent cut and avoid doing the maintenance.

    I'm getting into some larger timber, like 12"X24"X32', and starting to get a diagonal washboard pattern.  It happens when I hit a knot or the travel speed is too high.  This is some really $$$ timber for a really $$$$ job and it has to look really good!  Here's a couple of pics.  Any idea how to avoid these marks.


https://forestryforum.com/gallery/index.php?cat=17063


   Thank for the knowledge I've already got from here, and thanks in advance for the help.

[zopi]

First guess is a dull or improperly set blade...second..worn guides/bearings...tension maybe off..

Do you have the repair/alignment manuals for the mill?  dunno about mighty might,
but WM includes alignment and troubleshooting info in the manuals..

[Cypress Man]

   Those washboard marks are created when the blade begins to dull.  If you listen closely you will hear the blade "sing" or vibrate when those marks are created.  These type marks are usually acceptable in rough cut lumber applications.  If you absolutely cannot have them, you must change to sharp blades move frequently.  Hope this helps.

[logwalker]

Welcome to the forum. Congratulations on your knew job also. When you say diagonal, how much are you getting. When I get the tooth marks I see in the pics it is one or more teeth set too much. And if you are pushing fast than it would be in a diagonal direction. How are you sharpening and setting? Let's start there. Joe

[fencerowphil (Phil L.)]

Welcome!

You sure are learninfast!

Of course, Mighty Mite's web site claims that you can be cutting great lumber in just
ten minutes with all the features that the Mark IVb has.  That's a nice mill!  Having the
mill to learn, as well as the sharpener/setter operation to master right off the bat is a
truly BIG JOB.  Actually, that is too much to expect, but you gotta' do... well you know.

Usually damaged blades will leave marks like that, OR blades with few teeth out of set.
I am not a bandmiller, but that is an observation from using shop bandsaws and from
having bandmillers do work for me.  You hit the nail on the head, because, if maintenance
in general has been poor, there are the tension and blade guide issues to deal with.

Please, ask that your employer invest in more training in you with Mighty Mite and with
the sharpener manufacturer.

Phil L.

[learninfast]

the diagonal is at maybe a 80-85* angle instead of 90*.  It happens even at a very slow travel speed, with a very sharp blade. 

  I have a Mighty Mite sharpener and kerf setter.  The setter has dial indicators pointing at each tooth.  When I was showed how to use it I was told to disregard the dial indicators because thats "too precise for a saw mill".  I was told "when the teeth look flat, put the blade in the setter, and bend and go."  Watching the dial indicators, I seem to get an inconsistent reading.  The sharpener is a fully auto, put the blade on and wlak away.  Thanks Joe!

Cypress man, it seems to happen even with a freshly sharpend blade.  I only run razor sharp blades, and resharpen at first signs of dulling(any signing and it's out a there. Usually about three cuts.  This is more of a finnish application, no uneven marks are acceptable, wood needs to have a clean cut, not furred out.  Thanks for the tips.

Zopi, I'm listening.  I'm starting to think I need to pay more attention to the setter.  The blade guides are newer, but may be set off.  I use a torpedo level to set them, I've heard WM makes a tool for it.  My manual says to use a dial indicator :-\.  The manual does have some trouble shooting info, but to be honest at this point a lot of it is over my head.  I'm running a 1 1/4" timberwolf blade and have been playing with tensions between 300-380psi.  It seems to washboard more at lower tensions.  Thanks for the heads up.

[Fla._Deadheader]

Not sure about your machine, but, tension needs to be a LOT tighter than 380 PSI. How is that tension number arrived at ???  Is this hydraulic tension, with a gauge ???  Is it manual tension ???

  We started out with Suffolk Timberwolf blades, and had all sorts of problems. Switched to Munksforsager, and the mill never looked back ???

  Try calling Mighty Mite Company for ideas ???

[learninfast]

Hi Phil, thanks for the reply.  Sounds like the setter needs a good going over.  What is recommended for cutting doug fir 8"-24" wide.  My blades come at 29 thou, but I'm not sure where the setter is.  About the asking for more training thing. I have been.  Not getting a real good response there.  I did finally get to go to Mighty Mite (they made the sharpener and setter I use also).  They make some nice machinery, but don't have a lot for a training program.  So, not knowing any old time sawyers in the area to have a beer and a chat with, leaves me looking to you guys for advice and encouragement.  Keep it coming.

Hi, Deadheader.  The tensioner is hydraulic.  It has a gauge displaying psi.  The manual recommends a max of 375.  Do you have a link for the Munksforsager blades. I'd like to look into them.  Suffolk of Washington also has a blade he's calling "German steel" It's 1 3/8" and I have tried some of them also.  They seem to break faster.

[LeeB]

You can get the Munk's blades from Menominee Saw, one of the sponcers here. Look at the ads on the left. Just looking at the pics I would say it is set. I also have to add that a mill in not for making finished lumber. What I'm seeing isn't really all that bad. I've had new blades do worse than that.

[jackpine]

If I understand you correctly, the washboarding is not the full length of the cant? If so, I get this quite often on my LT40 either at the beginning of the cut or at a large knot in white pine. I believe it is due to a combination of blade tension, too little?, and feed speed but feed speed seems to have the most affect. What I cannot tell you is which way to go with the speed as it does not bother me too much and I have not experimented with trying a different speed at that point in the cant. If it were blade set it would show up the full length of the cant.

Bill

[fencerowphil (Phil L.)]

I love this statement:

When I was showed how to use it I was told to disregard the dial indicators because thats
"too precise for a saw mill".  I was told "when the teeth look flat, put the blade in the setter, and
bend and go."

That may be true to whack up a whack o' logs, as we like to say here on the FF,
BUT...
if you want the precision finished smooth beams, you will only get it with precision-set teeth.
Too much set could cause a knot to set up a vibration temporarily, causing the washboarding.
You may want to invest some of your time in refining your sharpening/setting.  Rather than
interrupt precious saw time when the entire crew is working, maybe get approval for a few
hours quiet time - but PAID time - to see what you can do to improve a few bands for the
next day's use.

[LeeB]

You might also want to check your drive belt tension. Could be chatter from too slow blade speed and more feed speed than it can handle at that blade speed. Is It a washboard effect or a grooved surface?

[learninfast]

If I understand you correctly, the washboarding is not the full length of the cant? If so, I get this quite often on my LT40 either at the beginning of the cut or at a large knot in white pine. I

A knot will set it off, then it will go away.

Too much set could cause a knot to set up a vibration temporarily, causing the washboarding.

I think it is an uneven set (not the same left to right), and too little tension on the blade.  I'll try and tweak on the setter, and bump the tension up a little tomorrow.

Hi Lee, drive belt tension could have been a part of it.  The drive belts looked warn and I have replaced them.  I scared of increasing drive belt tensioning because of stress on the crank.  I basically tightened it until it would quit flopping at full throttle.  It still flops a little while at idle.  I thought a washboard was a grooved surface.  Anyways, it's very evenly spaced grooves that are not at a 90* angle to the beam.  I'll try and improve on the pic.

Thanks, for all the help.

Luke

[LeeB]

More set on one side would cause the blade to follow the side with the most set and you would get dip or rise. After reading yuor original post again, I see you stated it is at knots and high feed rate. May well be blade tension and I still suspect drive belt tension. Part of the problem around the knots is that band blades are ripping blades and cutting at a knot is cross cutting, which will make your blade chatter some. Slow down a little at the knots.

[learninfast]

Here's a closer shot.

https://forestryforum.com/gallery/displayimage.php?album=random&cat=17063&pos=-61703

[zopi]

something else occurs...with the obvious lack of care in the setting dept, blades that ought to be skip tooth, ie one set one way, one neutral and one set the other way,the blades might have been set every other tooth...that neutral tooth carries loose sawdust out of the tooth..it'll cut some, but it's mostly for clearing the kerf..

WM's blade guide setter is a straight piece of aluminum bar with a clip to hold it on the blade and parallel with the bed ways..

also dig around on various blade manufacturers sites..there is a wealth of info on some of them..

[LeeB]

zopi, they'll cut just fine without the raker.

[Bro. Noble]

Welcome to the forum,

Most problems a guy runs into with improper cutting is from blades not sharpened or set correctly.  Even though you have just sharpened a blade doesn't necessarily mean it's sharpened right.  I've done this for about 15 years and still fail to get one right from time to time for various reasons,  so don't think I'm picking on a newbie.  A good thing for a beginner ( and some of us oldtimers too ) to do is to keep a new blade handy.  If the new blade does the same thing,  then look past the blade for the problem.  If the new blade cuts well,  check out your sharpening and setting machinery and techniques.

As you learn,  stick close to this forum because some of us have had any problem that you will face. 

[David Freed]

I am not a sawyer, and I can't help with setting your saw right. From all the pictures you have posted so far, I haven't seen anything that wouldn't clean up with one pass through the planer. In my opinion the problem is the customer expecting a smooth finish from a sawmill. I have dealt with a lot of sawmills. Every one of them would laugh if you asked them for a finish that good. I know this doesn't help you any, but I think you are being asked to do something completely unreasonable.

[fencerowphil (Phil L.)]

After studying the Mark IVB a little more...

I noticed that its max h.p. is 38.  That is surprising for such a serious saw.
When cutting a 24" wide beam,  38h.p. is not a lot.   A wide cut, plus a  knot would
potentially reduce your band's feet-per-minute.  I expected to see around 50h.p.

That said, ... a summary is in order:   :P

                     Teeth set correctly to spec for the wood
                            That would include consistent setting which is also not so excessive
                             as to encourage chatter at the knots.  Just enough, not too much.
                             (Excessive set can also rob horse power on your widest cuts.)
                             Let's not forget the hook angle either.  Is the grinding stone correctly
                             profiled?  It might not have been maintained either.

                     Slowing down for knots, as LeeB said, to prevent chatter and loss of band speed
                            That would be indicated not only by what has been said, but also
                             by the fact that your horsepower may be on the low side.
                            (I think Customsawyer is running 62 h.p. on his WM LT70, for example.)


Now, you know we will be eager to see what you really find as the solution.

That is your payment for all this hot air from us!     :D    :D

Phil L.

[shinnlinger]

HI Luke,

I lived in Eugene for about 8 years, welcome,  but I am with Dave.  A planer will easily take care of that.

Did the old guy get smoother cuts?  Does any one reading this get much smoother cuts?  The pics you show are ussually what I get with my bandmill and just considerd that good for "roughcut lumber"

BUt the big question Luke is does  the company  expect planer smooth right off the mill?

There is a link around her somewhere where a guy hung a planer off his mill to plane the beams while the sat on the mill.

[logwalker]

First, that is not a bad finish but it could get better.

Second, .029" is to much set for a hard not in Doug fir. I would drop back to .024" and see. And they need to be within a few thous. of each other. Always slow at the big knots. If you are walking with the saw it is easiest to hold the saw back physically as you enter the knot and release it as you leave.

Third, that pressure sure sounds way to low. We use 2300/3000 lbs of hydraulic pressure on the LT40's. Measure the blade stretch with a set of calipers and record the amount of gage pressure it takes to stretch the band about .005 or .006". There is a thread with instructions somewhere on the forum. You just open the calipers to 6" and clamp to the exposed blade with two c-clamps. Tighten the tension until the blade stretches .006" in the 6" section. This will be accurate for most blades. You can talk with the manufacturer and double check.

[learninfast]

   The last sawyer was getting some pretty smooth cuts.  They weren't planer smooth, but they didn't have any uneven marks, or hairs sticking up.  You can wipe the sawdust off with your hand without worrying about splinters.  The problem with using a planer, besides the fact that we don't have one that big, is that it wouldn't look resawn.  They are going for the band saw lines on the wood, but very clean and even ones.  Like you get from your first cut or two on a sharpend blade.  Just when it doesn't look like it was cut with a brand new blade, I change blades.  Spend lots of time on the sharpener, and go threw lots of blades, but it puts out some really clean cuts.  It's not unreasonable to ask for, you just have to expect that it's going to cost a lot. 

   Phil, you've been checking up on the mill.  The 38HP you read must be for the Perkins they are using now.  The one I am running has a little 3-cyl. Isuzu thats pushing 33HP, on a good day.  I just recently discovered how important it was to clean the air filter.  After not cleaning it for three months the entire housing was full of sawdust.  The engine was missing pretty bad.  Doubt I had 33HP at that point.  Oh so many variables. 

So summary: -Wood was frozen(forgot to throw that in)- it should be thawed now
                      -33HP engine was running poorly- cleaned air filter, stopped missing
                      -setter may be off- what kerf do you guys cut doug fur at?
                      -sharpener may be off- what hook angle should fir be cut at? 


I have been maintaining a rounded profile on the sharpening stone.  Slowing the thing down anymore isn't really possible or desirable.  I had the thing creeping so slow on some of these that you could barley tell it was moving.  Still got marks in the wood.

    I was about ready to throw my hands up and walk away, until someone told me, "you don't just get to be head sawyer over night, there's guys that have been at the mill 15 years and are still learning."  It kinda put it into perspective for me.  So much to it.  I still got a lot to learn
                     
                     

[fencerowphil (Phil L.)]

LogWalker,

I bet the gauge on the Mighty Mite is reading tension in simple pounds, not pounds per square inch.
Even though we are familiar with PSI in rating the tensile strength of steel,  I don't think
the psi would apply to numbers like the range which learninfast is mentioning.  The manual would
define that for us, of course.

Heck, there are piano strings with almost 380 lbs of tension on them in many large grand
pianos - on a wire only .055" in diameter!  If you convert 380 lbs. of straight line tension to PSI, you
get about 5428 lbs. psi for a 1.25 by .055 blade!  Now thassaliddlebitight!

We are really just talking tension on the blade, as if weighted by 380 lbs - straight line vector.

Phil L.                        P.S.   That piano wire of .055" diameter at 380 lbs would be
                                          a psi equivalent of about 38,000 pounds.
                                          How's that for tough wire, huh?

[jesse]

i get marks like that on 10" and wider cuts but dont seem to get marks like that on the smaller cuts when the blade can be kept moving on the 10" and up i have to keep the feed as slow as it will go to keep motor running

[Cypress Man]

  I agree with Bro. Noble.  Get a brand new blade out of the box and I am sure this problem will go away.  I saw cypress every day on a Woodmizer Lt40 Super 25HP 3Phase electric using .055 thick blades.  I usually tend to cut even when the blade begins to dull and this exact washboard effect will happen. Notice if you increase the feed rate this will minimize it but it will not eliminate it.  The blade is "dull"!!!  If it is not sharpened correctly and set correctly it will not cut smoothly.  It is not a tension problem!  Dont try a blade you sharpened or set, get a brand new one and see. 

                                                                                                                                      Cypress Man

[fencerowphil (Phil L.)]

http://www.suffolkmachinery.com/six_rules.asp

http://www.suffolkmachinery.com/set_hook_angles.asp


I noticed where Logdog has posted these in another thread.  Enjoy!

I think you will have a "light bulb" or two go off, when you look at the
set figures for frozen wood.  Also,  wouldn't you class Douglas Fir in
the "medium hard" category?  Think I would.  That means less set than
say EWP or Spruce.
Phil L.

[learninfast]

WOW   8)

Thanks Phil,
    That was more than just lights going off.  I was jaw dropped, hand on my forehead the whole time I was reading that.  More than one thing I've been doing wrong. 

Gotta go to work, I'll try a few new things and report back.

Thanks for the help,

Luke

[learninfast]

   Quick updated for you guys.  I have been paying closer attention to the setter.  Still can't get the dial indicators to make any sense.  I don't think the bars are clamping down tight enough on the band to hold it.  I get all kinds of different readings.

   I noticed the blade was starting to wobble back where it came out of the housing on the idler side.  Looks like one of the main bearings on the idler side is shot.  I got two new bearing, hopefully this will smooth out the cut a little.

thanks for the help

[learninfast]

    For the past month or so it had been getting harder and harder to make a clean cut.  I kept slowing the travel speed till I was running 2-4 fpm   I was only getting two or three cuts per blade sharpening .   Lots of blade chatter(diagonal washboard look), blade would randomly(leaving random lines in the cut).  I've been chasing my tail, changing warn parts, adjusting darn near everything there is to adjust on the mill, setter, and sharpener.  Finally last week the sleeve in one of the idler bearings shattered. 

  I got the new bearings in and it's smoothed out A WHOLE LOT! Ran it for the last couple days and the feed rate is back up, my blades are lasting longer, and the cuts are back to nearly planer smooth!

  I have to say it's been quite a crash course in mill troubleshooting.  I probably replaced a few things that didn't need it, but I also replaced some things that really needed it.  At least the mill is back up to par and I can start doing more cutting, less repairing.  It's no fun working on the mill, when there's a big pile of wood waiting to be cut.

   Thanks to all with the help diagnosing the problem.  I have learned a lot about sharpening and setting from you guys.  I have got the setter making more sense now.  I have backed down to 24 thou for cuts 12" or less, but have some blades at 29 thou for the wider cuts.

[ely]

i get lines like those in my pine all the time and i like em just fine. sounds like you are doing well now, good luck with your sawmilling and glad to have you on the site.

[John Bartley]

If you'll allow another newbie to jump in here .... The guys who have been so helpful to you in this thread were equally helpful to me in another thread and it was really appreciated!!  In researching my troubles of wavy, frozen White Pine cuts, and following the leads given to me on this forum, I found the following helped me:

• Timberwolf bands are (apparently) made by Hakansson and are silicone steel
• Hakansson recommends that you use the Suffolk "blade flutter" test for setting the tension on your mill rather than set according to the pressure guage.
• When pressed, Hakansson will say that they recommend approximately 18,000 to 20,000 (same as the Munksfor bands) pounds of strain on the band. I found this to be equivalent to 0.0035" of stretch on a 5" span.
• In my frozen White Pine, a set of 0.025" and strain at 20,000pounds made for perfect cuts up to 22" wide.
• I get lines across the boards when I set a tooth out farther then the rest

That's all I got ... I hope it helps...

cheers from a real beginner eh?

John