Wavy Cuts

[woodman58]

 I have a guy that saws for me on occation. He has a Woodmizer LT40. The last few times he cut for me the cuts have been very wavy. What can I tell him to do to fix this problem with out insulting him. He has been cutting for 15 years.
The other person that cuts for me has a Baker 3665. The cuts are always true. He is moving futher away in 2 months and semi retiring, so I'm going to have to use the other guy. Thanks

[Burlkraft]

Boards like that turn your planer into a skip planer  ;D  ;D  ;D

[ronwood]

woodman58,

Sounds like he is trying to cut to fast and using blades that are dull. Could be a issue with the mill also. Has he always cut wavy lumber.

Ron

[John Bartley]

My experience is this:

1 - bands that are dull but properly set for the type of wood, will cut slowly and will load the engine down. They also seem to gather the most dust and pitch.

2 - bands that are under-set for the type of wood they are cutting, will almost always produce a wavy cut, regardless how sharp they are.

3 - bands that are over-set will produce more sawdust then is necessary, but if they are sharp, they will cut just as well as a properly set and sharpened band.

that's all I got...

John

[Bro. Noble]

In addition to John's list,  a dull blade runs warm and picks up sap from the wood.  If you don't run enough water, the sap buildup has the effect of removing set, causing wavy cuts.

I feel my blade for warming (not while it's running :) and start thinking about changing it when it begins to feel warm.

[dkyle]

what do you mean by "over-set", "under-set"?
I suspect the guy is running the blade too long.. it is dull, and running hotter than it should.  It expands and is now running is looser.

[woodman58]

One thing I forgot to mention is that he does not run water on the blade. His hose is broken. He says it works fine without it.

[weisyboy]

dosent sound like it works fine to me.

[paul case]

dosent sound like it works fine to me.

i  almost said that, thanks for posting it so i didnt have to.
my exp.  dull blade  pushing to fast. no lube can do it too if the sap builds up on the blade like noble said.   pc

[Tom Sawyer]

One other factor would be the kind of wood he is cutting.  Spruce will sometimes give me fits no matter how sharp or well set my blades are.  I always make sure the customer knows that wavy wood is not acceptable to me as the sawyer, and on the one occasion that I couldn't cut a customer's spruce straight no matter how hard I tried, his bill was discounted significantly. 

Amen to weisyboy and Paul Case.

Tom

[backwoods sawyer]

The saw tracking to far back on the wheel will take the set right out of a new saw.
Worn guides will not hold the blade flat in the cut.
Not having enough tension on the saw will allow the saw to wander.
Get the water flowing even if that mean using a garden hose on the saw or the sawyer.

[Magicman]

"Folks" that saw wavy lumber are good for my business.  Their former customers are my future customers.  Notice that I didn't call him a "sawyer".

He has a sawmill and saws logs, but a sawmill don't a sawyer make.

[tazz]

One thing I forgot to mention is that he does not run water on the blade. His hose is broken. He says it works fine without it.

I have noticed everytime I let my water tank run empty my cuts get wavy, even with a new blade on. You should let him know, this could cause him to lose a lot of business. I know if it were me I would want to know.

[sgschwend]

Wavy where?  At the beginning of the cut, around the knots, on the edges of the board, only on the large knots, or anywhere on the board?

All of those places have their own cause and effect.

[John Bartley]

what do you mean by "over-set", "under-set"?

When a band is made, the teeth tips are alternately bent left and right so that the band cuts wider than the thickness of the band material. This is called the "set" of the tooth. On the bands that I use the set pattern is Left - Right - None, so every third tooth tip is bent (set) the same way. When a tooth tip is bent too far (over-set), the kerf in the cant is wider than it needs to be and extra energy and wood are wasted making sawdust that could be a board. When a tooth tip is not bent over far enough (under-set), the result is often a wavy cut accompanied by a band that runs warm and builds up pitch.

FYI : I'm no expert.....not even close to being one......this is just my experience so far.

cheers

John

[gator gar]

If he has been cutting for 15 years, he has it figured out by now. My opinion is that he just don't care and has little or no pride in his work. I'd find another person to saw for me in the future.

[bandmiller2]

Woodman,perfect excuse to get your own mill.Frank C.

[ladylake]

  We all get a wavy cut once in a while but should not get 2 in a row.   Steve

[barbender]

If he's been doing this for 15 years and is sawing a large amount of wavy lumber, either he doesn't care about quality, or he doesn't know what he is doing. I'd say an occasional wavy cut is to be expected, but the situation should be fixed right away. Bottom line- I'd find someone else. ;)

[Chuck White]

Other than mill alignment, wavy cuts are caused by:
Dull blade.
Not enough lube (pitch build-up).
The set doesn't match the wood being cut.
Pushing a dull blade too hard/fast.

My money says that the other guy doesn't sharpen his own blades and/or have a good resharp service.

I found that once I got my own Sharpening/Setting equipment, I pull the blades off the mill at first sign of a wave or the engine laboring.

"Folks" that saw wavy lumber are good for my business.  Their former customers are my future customers.  Notice that I didn't call him a "sawyer".

He has a sawmill and saws logs, but a sawmill don't a sawyer make.

I have quite a few of those too Magicman.  ;D

[Meadows Miller]

Gday

Magic was Spot on With his comment that there is a big difference between a Sawyer and someone who Has a Sawmill Mate  ;)
A sawyer who takes pride in their work and  equipment ,how they maintain it and operate it will produce consitant quality Timber Day in Day out Without Fail  ;) and id recomend that you take the time between now and when your current reliable sawyer retires to suss out and find yourself a good one if not persist with this one just put it to him that he wont be getting paid for miss cuts  Mate  ;)

Good Luck

Regards Chris

[LeeB]

Just an addendum to Cris's post. "suss out" means to figure out.

[Magic Smoke]

If he has used several blades (especially a new one) and it cuts wavy right off the bat, then the issue is probably not the blade. Something as simple as a loose drive belt can cause wavy cuts... when the belt slips, the blade slows down causing wavy cuts (especially in wide cuts). If the drive belt is good and tight then he needs to do a blade guide alignment.

[JRHill]

Noticed this thread while researching some ideas and solutions for wavy cuts.

I have a WoodMizer LT50HD. I use the WoodMizer soap/lube. A few months back the blade got below the leading blade guide/roller. I didn't notice when I started the cut and mid way through the mill was bogging and the blade was steaming. It was a quick shut down and the dreaded "stuck in the middle of the log" scenario. The blade was being pushed to the rear of the slot in the bracket and pushing metal on metal on the guide bracket. Blade was burned on the rear edge, of course, and now junk. When freeing it and removing I saw the blade wheel belts were burned/scorched. Dang. Got new factory belts and replaced them - it was probably time anyway.

But darn it, since this happened I can not get a straight cut out of the saw. Even with fresh blades. I'm sawing 2 to 3 year old 12 to 16" Doug Fir that was bunked and with relatively clean bark (I have a debarker and use it when needed anyway but no stuck rocks or stones). I've inspected the blade guides and jewelry and all looks good. I think this batch of blades were resharps but can't recall now. I do have a box of new ones but *DanG I don't want to trash another blade let alone a new blade. And I've NEVER had a bad experience with resharps from Woodmizer's Portland store.



Any ideas?

Best from WA,
JRHill

[alan gage]

So you haven't gotten a single straight cut since the incident? I assume you've tried multiple logs?

Alan

[YellowHammer]

Unfortunately, to eliminate variables, it's best to try with a new blade and new bandwheel belts.  Most of this below can be done in a very few minutes.  

Check band tracking on the bandwheels.

Check the band roller guides for flat spots or grooves cut into the back shoulder.  Check for flat spots on the contact surface with no band on. 

Check to make sure they are rolling smoothly with no band on, and with no wobble.

Check the make sure the idle side blade guide arm is rock solid, with no band on.  Tug on it hard, back and forth, up and down.

Make sure your HP blade guides are rock solid with the band on and are not touching the band.

Make sure both guide block assemblies are still rock solid.

Check their alignment.

Check the main drive belt tension (very important any time there is a loss in cut quality). 

Check band alignment.

[Bandmill Bandit]

Lots of relevant advice BUT, MM nailed it! "Owning a saw mill dont a sawyer make"!

If some one showed up to my place with "mangled components" hanging off his mill, he wouldn't even get a chance to set up. if he is too dumb to KNOW that blade lube is NOT optional, he is to dumb to understand MOST of the principles of cutting good lumber, weather it laziness or his "give a *DanG is busted"! He DON'T deserve patronage ($$) from me or any one else.

A good owner and operator will produce good lumber no matter the mill brand.

Its just that a good operator can make more good lumber faster with not as much work on a Woodmizer. ;D  :D    

[Brad_bb]

All these posts and the OP has never said what type of wood was being cut or how frequently the waves were occurring, whether the wood being cut was knotty or not...

These will help focus or eliminate what might be going on.  

If you are getting fairly consistent wavy lumber from him, I'd lay a bunch out and inspect it with him.  If he blows it off and tells you it'll get flat in planing....then that tells you he doesn't care.  If he want's to trouble shoot it with you, then that's a good thing.

Among the other causes that have been listed, my waves have been caused by 1)the band, 2)drive belt tension(too loose), and 3) the wood itself.  Milling really hard wood like osage, I'll get more waves than normal because it's so hard and the the band will sometimes try to follow changing grain direction.  I also proved the same thing when cutting Honey locust.  It's pretty hard too, but the knots are extra hard, and depending whether you're cutting up or down the tree when you hit the branch knot, affects which direction the blade wants to go- up or down.  When cutting really hard wood, or wood with really hard knots, you need to slow your feed rate down for sure for those. If you try to continue at the normal feedrate, when it hits hard and quickly changing grain direction, the band will try to follow-  the path of least resistance.  Slowing the feed rate down so the teeth can cut through the knot fibers before the blade advances.

This thread is a good reminder to me to check my drive belt tension.  I'm going to be cutting a bunch of osage soon and I need to make sure it's correct before I do.

[Bandmill Bandit]

This thread is a good reminder to me to check my drive belt tension.  I'm going to be cutting a bunch of osage soon and I need to make sure it's correct before I do.

You are bang on that one Brad!
I have learned that I can do hand check of the belt by raising the head and reaching in from the bottom. I check it cold and then again after a log is cut every time I fire up the mill. That way the belt don't get a chance to delivery wavy lumber. Having said that, WHEN I do see a wavy board it is the FIRST thing I check 

[GDinMaine]

It could have been a the wood as well. A bone-dry spruce, cherry, ash, oak and so on, will do funny things to the blade and makes you scratch you head as for what might be wrong. For me dry spruce presents the greatest challenge. The knots are very hard and in the transition the blade makes waves. I tend to see smaller, but more frequent waves caused high feed rate in tough wood as opposed to long, more gentle waves caused by dull blade issues. The first thing I try is slow the feed down. Sometimes way down. If that does not help I put on a fresh blade right away. If I do make some wavy lumber I always point it out to the customer and immediately start looking for a solution, even if they say they don't care. I hate doing a bad job and I get very frustrated by crappy lumber. 

[Percy]

  For me dry spruce presents the greatest challenge. The knots are very hard and in the transition the blade makes waves. I tend to see smaller, but more frequent waves caused high feed rate in tough wood as opposed to long, more gentle waves caused by dull blade issues.  

I couldnt agree more...Dry spruce, specially the bigger ones, the blade sounds like its cutting a rock the whole way down the log.... :D :D

[rastis]

My experience is this:

1 - bands that are dull but properly set for the type of wood, will cut slowly and will load the engine down. They also seem to gather the most dust and pitch.

2 - bands that are under-set for the type of wood they are cutting, will almost always produce a wavy cut, regardless how sharp they are.

3 - bands that are over-set will produce more sawdust then is necessary, but if they are sharp, they will cut just as well as a properly set and sharpened band.

that's all I got...

John

Is there a guide available for type of band and tooth set to use for various wood species? I've been contemplating getting the gear to sharpen and set my own bands. We cut pine, maple, oak, cherry and walnut or whatever species the wood fairy happens to deliver.

[CCCLLC]

Wood Mizer site has some lists and guides on that in their blade selection pages. Maybe a copy for Sawyer as a curtisy as well. 

[Stephen1]

I am always going to sawmill jobs where I am asked if I am going to cut wavey wood. How often did the last guy change his blade, i ask? change a blade they say, he used the same blade all day. 
NO I do not cut more than 1 wavey board as I change the blade, adjust what I need to make sure we are sawing perfect or near perfect lumber. 
I am seeing wavey lumber at the kiln now from someone elses sawing, slabs cut thru the pith and then they wonder why it spits and moves in the kiln.
I really do not want someone swearing at me and giving me a bad name because they had to send a board thru the planer numerous times.

[JRHill]

Well, *DanG.

Broke everything down, inspected and back together with a fresh blade but not new wheel belts. I got the Woodmizer tool out and checked all the blade alignment specs. A few weren't "perfect" as the millennial kids say but well close enough. I buttoned it up and loaded the lube jug, checked everything again and it ran a perfect cut.





It is just another of those things where ya fight it and then when ya put it back together the problem evaporates. you never get to find out what was wrong. But thanks for all the input.

[bushhog920]

So what do y'all set to for different types of wood? I cut mostly pine and shoot for .025" 

[JRHill]

So what do y'all set to for different types of wood? I cut mostly pine and shoot for .025"

Not sure what you mean... .025 straightness in the cut? I don't have any difference in pine from Doug fir, er when I'm not battling an elusive weird thing like the above. 

[bushhog920]

Tooth set on the blade sorry should have been more clear. .025" seems good for me if I over set to .030" my boards start getting a rough surface finish.

[Chuck White]

I cut mostly W/Pine, Hemlock & Cherry and I set my blades in the .025-.028 area!

If you try to get them set to the "exact" number, it can get very frustrating!

[dougtrr2]

If he has been cutting for 15 years, he has it figured out by now. My opinion is that he just don't care and has little or no pride in his work. I'd find another person to saw for me in the future.

There is a difference between "cutting for 15 years" and "cutting for one year 15 times".   Maybe he just isn't learning.
Doug in SW IA

[Bandmill Bandit]

FYI Re dry spruce; 
And this don't always work.

I like to load small end to the front of mill BUT have spun the log end for end after a first cut that showed waves where ever I hit a sizable knot in that first cut. Most times that will solve it. Other time it just changes which way the blade deflects.

Hit the log from the small end blade tends to dive at the knot and hit from the butt end blade tends to climb. I thought I was bonkers the first time I noticed it but its pretty much the way it works out MOST of time.    

[Poquo]

Yesterday was milling Pine everything was working fine then the blade started diving in the cut . Checked almost everything on the mill , put new blade on still dived , finally noticed lube was stopped up and barely dripping . Unclogged line mill cut fine after that .

[chickenchaser]

Kicking this one back to the top as it does me good to review/refresh....
Is it legal for me to do that?
CC