Sawed up a big pin oak today and it was frustrating!!! I had a 21" cant - 11 feet long on the mill. I cut it into thirds and turned it 90 degrees to cut a bunch of 1x's out of it. There was some movement going on with the cant but the boards weren't moving so I thought I better turn them 180? I found out this wasn't so easy, three 7x21 slabs standing on end don't want to turn 180 with the log turner. So... I had them scattered all over the deck of the mill. Better go get the tractor, got them all stacked backed up and away I went. Got them all cut and tried lifting the pile off the mill with the tractor and got it stuck in the muddy mess that is in front of the sawmill shed. Had to let down the stack of lumber half on and half off the mill. Then, I backed the truck down to the mill and picked up all the boards and put them in the back of the 4x4 truck ( its a muddy mess out here I need a road to the mill shed). As I am loading all this lumber from the mud hole I start to see how wavy a lot of the cuts are. I didn't see it while I was cutting. It sure upset me, I still don't understand why. Was it the hard old pin oak or the blade not tight enough? I put a new blade on before I started. I didn't cut fast, why did I have so many wavey boards. I am a *DanG rookie and it is frustrating figuring out how to become a sawyer I am glad you guys are here to help!! The boards can all be easily fixed with a little planing and joining but I sure don't like delivering wavey boards to a customer. The wife keeps reminding me its " rough cut lumber " it's not suppose to be perfect. Can I consistently deliver nice flat faces and edges square and straight with my bandmill or will I have some wavey stuff??
Buddy, I got the same problem. I'm always trying to microanalyze it and see why it is-- blade not tight enough, log too tough, too many knots, stress in the log, the blade is too dull (and why is that, I JUST replaced it???), am I using the wrong type of blade, etc. etc. etc. ad infinitum. Seems like I can barely mill 50 bf an hour a lot of times. Maybe some of the experts will help us out. ;)
In my experience, you should be able to produce consistent lumber without waves. Although I don't know what it is, there is something awry. On a 21" wide cut, maybe you are going too fast?
Wider cuts, like those used to break down a log or large cant, are the hardest to keep flat or wave free. Using my sharpest blade, adjusting lubrication and tensioner in the cut for consistent high blade tension, and an even modest feed rate are my main strategies. Choosing a 9 degree or 4 degree blade for me, in knotty oak, are two others which help. If these don't do it I just break down oversize real quick and then resaw the narrower pieces with new cuts. Waviness is easily seen by looking down the edge formed by two of your cuts. You can also sight along the line of the cut, while it is being made, to see whether cuts are flat or wavy.
ronnie be sure to check your guides,meaning alignment.sometimes if the band has just the smallest bit of tilt up or down it will show up in a wide cut.i keep a 4 ft level handy so i can lay it up on the cant and see even the smallest dip .like yourself i can't stand wavey lumber.as others have said sharp band and proper set goes a long way.woodmizer sells that neat little tool to clip on your band and check alignment,i use mine often. hope you get it figured out al
the wider the cut the more waves you'll get. for me i'll take 2 of those cants and put them on the loader arms and just cut 1 cant at a time. i can cut it faster and more accuratly than trying to do all at once.
are you keeping your blade guides moved in to about touching the cant?
p.s from a guy(me) that does alot of planing don't get the mind set that "its rough sawn lumber so thats close enough"your lumber will tell the whole story about the sawyer that sawed it.your reputation will make or break your operation :)
First use a 4* blade for wide pin oak.. As red oak said cut them 1 at a time or maybe 2 first then the last one, 14" should cut straight with a good blade. Also it seems like 1 21" cant will cut better than when it's split into 2 or 3 pieces. Last, buy some gravel. I hate mud. I've hauled in at least 30 loads and can still use more. Steve
Well your in my zone now... big knotty pine.
I tend to get a lot of large knotty loblolly pine, it's not uncommon to square out a cant at 18-21 inches.
You will fine that a sawmill setup and blade that cuts fine in clear sawgrade pine or oak will founder in that knotty pine. Giving you wavy cuts and great frustration.
If the blade rides up or down and stays or if the wavy cutting passes straight into smaller clear saw grade timber it's sawmill alignment,
primary contributures of the problem.
-excessive feed speed, slow down to a crawl especilly for the knots
-too little set, increase your set but not enough to cause packed sawdust in the cut
-dull blade, try a newly sharpened blade, don't hesitate to try a different blade forcomparison
-pitch on the blade, increase lube, keep the blade clean reducing pitch related deviation and heat
Add patientce, you cannot cut large knotty cants anywhere near the production rate or feed speed of smaller clear stock. It is an inhearant limitation to the blade size and strength of the 1 1/2 band blade
I think we all like to see nice wide boards but to be honest they are a PITA to do. For me it's lots of lube, fresh blade, good tension on the blade and a slow feed rate. Not sure what you're using for blades but when I do white oak I use the 7°.
Can you tell what angle the teeth are just by looking at them? They are so small I don't know how I could ever measure the angle accurately.
Okrafarmer, what kind of blades do you use? The box/packing slip should have the hook angle.
Lost that info, I think. Got all the bands with the machine a couple years ago. A few of them were new, but the rest were used-- anyway, I think I lost all the info about them. The owner (a member on here) told us they were 1 7/8" blades that were a good compromise for softwood and hardwood, but I would like to get some that are especially for hardwood.
As others have said.... Too Wide. 21 inches is possible but to do it youd want your brand new sharpened blade on, feed slow, lube,etc. In other words only for exceptional cuts. Youre way better off IMO cutting 2 or 1 cants at a time.As also said, your cuts will make your rep. Wavey boards are visible forever, as is the memory of who cut them. Better to cut narrow, get straight cuts and build a solid rep. As someone said (words to live by IMO)"in a few yewars no one will ask how long it took theyll want to know who did it"
I think that WM and maybe other manufacturers have sold gauges to measure tooth angle. The angle is the number of degrees from perpendicular (90°) that the teeth slant. This would mean that a 10° blade is set at an 80° angle and a 4° blade is set at an 86° angle.
To me, it would be very difficult or impossible to tell them apart without an aid of some sort. I painted the weld red on my 7° blades.
You can use a carpenters angle guage then measure the hook angle. I use a gravity based angle finder when setting my sharpener. It's quick and easy.
Red Oaks beat me to the main thing I was going to say. The only thing that I would add is to check that your bolts are tight that hold the blade rollers. I am talking about the bolts that you use to adjust the rollers. You might want to make sure that the blade guide arm is tight also.
you can also oversize the parts a bit and then true them up for the grade cuts. Like everyone said saw one at a time. While your checking the guide rollers make sure theres no flat spots. Dont settle on wavy boards.
I want to eventually get to where I separate my slab-off cuts from my cant-- iow, slab off a few logs, change the blade, and start fresh on the cants with a sharp blade. But that requires extra handling. So I'm also concluding upgrading to a swing mill will solve most of these problems. But that's a big jump I'm not ready for financially.
Looking at that log in your other post most likely your blade was dull by time you got it squared up. Those big old logs can and do hold a lot of dirt. Steve
first thing i see is the type of log you have. a very wise friend named Tom, told me that pin oak-water oak, was really best used for firewood. i have since found that to be correct. works well for trailer decks and dump truck side boards.
as the others have said, sharp bands and a good setup on the saw is paramount.
Quote from: Magicman on March 25, 2012, 06:16:34 PM
I think that WM and maybe other manufacturers have sold gauges to measure tooth angle. The angle is the number of degrees from perpendicular (90°) that the teeth slant. This would mean that a 10° blade is set at an 80° angle and a 4° blade is set at an 86° angle.
To me, it would be very difficult or impossible to tell them apart without an aid of some sort. I painted the weld red on my 7° blades.
I asked for one of those gauges a couple months ago and was told they no longer sell them.
Ronnie,
I've been there, wavy cuts are embarassing. Reading the forum posts can give you lots of ideas like alignment, rollers, angles, etc. but the most reliable remedy that has worked for me is changing the blade. My mill alignment has been really solid.
As soon as I detect a wavy cut I change the blade. Sometimes I don't see it so much as feel it with my hand as I check the face. Ideally, before the client could bring it to my attention. When I start changing the blade I'll explain why and, in many cases, they may not have even noticed but I'd rather they know right away (and that I'm correcting it) than to have them not find out until they are stacking or using it in their shop. Most clients realize that machinery is not infallible but inattentiveness can damage your reputation.
For quite some time I kept a couple of brand new blades in my box for just that situation. I've had blades that had been resharpened but not set. One day I changed a dull, but straight cutting, blade and the first cut with a resharpened blade was wavy. Changed the blade again - again a wavy cut. Frustrated and somewhat embarassed, I put on a new blade and cuts were dead straight for the remainder of the day. Took the blades back and they couldn't see any set, both in the blades that had made one cut or the ones I hadn't used yet. They had no idea what happened but re-did them and they cut fine after that. I had been looking closely at blades while cleaning them before sending them in but not after they were returned. I do now.
Varying the blade angle sounds interesting and I'd like to try that but where my blades are resharpened only does 10° as far as I know. It is getting to the point where buying a sharpener/setter rig may make sense. :)
Don't forget the drive belt. This is often an overlooked item, when the belt slips your blade slows down and you get a wavy cut. The wider cuts are often when this shows up.
And power feed belt tension, that one might not be listed in the book as things to check.
No power feed belt on TK mills, just a hyd motor driving a chain. Steve
Quote from: Magic Smoke on March 26, 2012, 01:15:26 PM
Don't forget the drive belt. This is often an overlooked item, when the belt slips your blade slows down and you get a wavy cut. The wider cuts are often when this shows up.
smiley_lit_bulb smiley_sidelightbulb smiley_idea smiley_sun
Maybe that's part of my problem. I'll have to check it.
I always watch the blade coming over the sawn face on the gig back, it's easy to see if you are getting any waves that way. Often I can hear when the blade is cutting waves because the guide rollers start to get quiet, the blade either is not contacting them anymore or with only light pressure.
Right on the sound of the blade when cutting, soon as it gets real quiet it's diving. He was sawing the whole cant without removing the boards so watching the blade on the way back would'nt work in this case. Steve
Thanks for everyone's help, it is greatly appreciated. I have a lot to learn but you guys are making it possible.
Thanks again
Ronnie
Today I tightened my drive belt and also tensioned my blade tighter than I've ever done before. It seemed to help. I detensioned my blade afterward-- first time I've ever done that, other than to change one out.
Who says that you cant teach an old dog new tricks :D. (Note: Just a metaphor, I am not calling you an old dog :)).
Quote from: WDH on March 27, 2012, 10:08:29 PM
Who says that you cant teach an old dog new tricks :D. (Note: Just a metaphor, I am not calling you an old dog :)).
There you go again..... :D :D :D
Quote from: WDH on March 27, 2012, 10:08:29 PM
Who says that you cant teach an old dog new tricks :D. (Note: Just a metaphor, I am not calling you an old dog :)).
:D I'm old enough to know better! But one thing I won't ever do is stop learning.
But Okra is quick to learn a new trick. He would fall for a bowl of grits any day.
No problem. And I didn't hear about them until I was 16. They're fine.
why wreck a bowl with grits? :D
While I sleep, others take over. ;D
if you dont sleep then being tricked with grits wont happen. :D :D the saying " grits happens" wont apply here :D :D :D ;D
Don't even close your eyes for a second :D. You have to stay constantly on guard smiley_sleeping.
if they sneak up on me will it scare the grit out of me smiley_nananana smiley_nananana
Not if there aren't any in you. ::)