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hazazil
hazazil's picture
wavy boards

So I got my new Norwood HD36 sawmill put together and cut a few logs. First log was a white cedar log I had laying around for a couple years. I just made a 4 x 4 out of that. It wasn't too wide in diameter so .....

 

2nd I grabbed a maple log that was just gonna be cut up for firewood(before I got the mill). It had some narly stuff going on near it's base. While cutting it I noticed the blade diving and rising. Cut another slab off it and it did the same thing but both times it was near the same spot in the log. I did read my manual and it said it could be caused by stress in the tree and I did observe a knot close by with the grain going in a weird direction around the knot.

 

3rdly I grabbed a pine log that was cut down a few months back. Was gonna make some stickers out of it. I squared it all up and cut 4/4 then lined em up to cut em 3/4. That's when I noticed the waves.

 

Now I was wondering if you could give me some information based on your experience, when having issues with wavy boards, how often or what fixed it for you.

 

I've read it can be a dull blade, issue with bandwheel alignment, bearings, stress in log, possibly cut speed?

 

I forgot to mention I put a brand new blade on and still had issues on the maple and the pine log.

 

Could tension be an issue? I don't have anything to measure tension on the blade. I've read about people putting too much tension and blades breaking. Is that pretty common? I've also read that blades stretch over time or if they get warmed up so might have to retension.

 

Is it also important to move the adjustable blade guide closer to the fixed guide depending on the width of the log you're cutting?

 

Thanks :)

 

Bill
Bill's picture

I try and keep the guide as close to the log as I can. If there was any dirt in either log the blade wounldn't stay sharp for long if your getting waves and slowing down doesn't help try more tension . Learning is trial and error each of us go through scratching our head wondering what to do next.

r.garrison1
r.garrison1's picture

Two other things to consider is blade tension and how the blade rides on the guides.

If the blade is too lax, not enought tension, then it will find it's own way a lot.

If the guides are too far back on the blade, and if the blade rides too far forward off the wheels, then the front doesn't have anything keeping the nose straight. The guide wheels should be far enough forward to keep the blade pointing forward, but not far enough forward to catch the point of the blade and flatten the set and dull the edge.

Renegade Sawmill
Renegade Sawmill's picture

Hi Hazazil and welcome to the forum.  I assume you are using ceramic guides, but I better ask to be sure?  And when tightening the blade, I've had good luck with 10 - 1/2 turns of the tightening handle.  That's 10 - 1/2 turns (5 full turns) after all the slack is out of the blade and it's taunt. 

 

 

hazazil
hazazil's picture

Thanks, yes ceramic guides. I've been doing 4 1/2. I tried 5 because I was having an issue with the blade scoring the slabs but it didn't help.

 

r.garrison1
r.garrison1's picture

One other thing is forward pressure on the saw; if you keep a constant gentle pressure, rather than a constant speed, then the blade stays more stable. If I am cutting soft wood with hard knots, I generally slow quite a bit when I come to knots that cause the RPM to change, or that seems to slow the cut.

hazazil
hazazil's picture

I've been cutting some oak logs lately that are pretty straight to start with. I haven't had any issues with any wavy slabs. I did end up making sure that the adjustable guide is stays close to the log that i'm cutting. 

 

I also watched a video that a guy from Norwood put out talking about tension. He said he experimented alot and 4 1/2 turns was what worked best for him. 

 

I also think that the blade could've been riding too close to the front of the bandsaw wheels.

 

Has anyone here ever came across new blades that have issues with scoring the wood? I've tried 2 new blade and it's scoring the wood. Mentioned it to an older guy who is experienced and said it was probably the blade. Changed blade and same thing. I tried going slower and that didn't help. Also checked the book for possible causes and checked my guides and seen no issues.

 

 

eddiemac
eddiemac's picture

Yes , new blades are not always perfect, though we expect them to be.  The new blades Norwood supplies, based on my long-ago purchases, are set for softwood logs like pine, spruce, etc.  Hardwoods take a smaller set  -  I use .021" on oak.  But if you are experiencing scoring, your blades are probably set unevenly (say .021" here and .029" there).  Some automated setters don't set very uniformly.  The best way to find out is to have a manual setter with a dial indicator (essential purchase).  Alternately, move your blade by hand and measure against a stationary board and see if one tooth sticks out more than the others  -   that's your culprit. Bend it back.

r.garrison1
r.garrison1's picture

I tried a new blade (from a box of blades I had used before) and couldn't cut straight. Took it off after two cuts.

For some reason, it climbed into the log, then tension kept trying to pull it back down. 

I suspect one side was set more than the other, or one side was set but not the other.

Haven't checked the blade, just mad at it because I was cutting a stack of 2X6 boards (wavy cut on 8 boards, #[email protected]%(^&)

 

WildManMilling
WildManMilling's picture

I've had the same problem with my h36. I've got some good cuts out of it now, but the quality for the cost isn't showing.

r.garrison1
r.garrison1's picture

 I have an LM29, and I've cut some monster logs on it (bigger than it was designed for), and I'm happy with it.

Problems I've had always were tied to some mis-alignment, incorect tension, or a blade problem.

If I had to buy again, I'd probably buy the same saw, but get some extras such as extra bunks, extra log stops, extra length.

Right now, I'm working on the length thing; planning on building a stationary longer bed, so I can line my mobile saw to the fixed bed, roll the head off onto the stationary bed, and use that when I want. When I want to be mobile, just roll it back to the mobile one I have.

I found some steel that will be the key part of the bed, in 20' lengths. Now all I need is the time to start setting it up. I may even make a 30' long bed, just because the place I found the steel is a recycler, and steel is by the pound (and cheap!!!).

 

hazazil
hazazil's picture

Thanks everyone for the help. Definately sounds like a cool idea r.garrison!

Renegade Sawmill
Renegade Sawmill's picture

r.garrison1, that is an AWESOME idea!

r.garrison1
r.garrison1's picture

If you do it, life will be easier if you make it like a dock; when you roll up, both are the same height. That keeps you from doing any heavy lifting. I'm planning on a couple little tags of steel on the fixed bed to line things up.

kirk
kirk's picture

hello i am new to the forum.  have a question for  veteran saw millers . i can not take up any more tension on mt blade the pin  is bottomed out is that an indication its time for new idler and drive belts

DaveM
DaveM's picture

Hi Gang !!  I have also recently been getting some wavey cuts with my HD36.  I've tried most of the commonly recommended fixes but to no avail.  The blade seems to be diving consistently as the saw head passes over the log dogs. Yes...I have switched blades twice.  I have insured the bed supports are all firmly on the ground & the mill bed is as perfectly level as I can get it.  I stretched a string along the bed rails on both sides as well as laid a 5' level on the tracks and both indicate that the rails are level & parallel on each side.  So....I am thinking I have something going on with the dogs & / or clamps.  Hopefully you guys have an idea as I am officially baffled.  It has done this consistently in those 2 spots on spruce, maple & beech.

r.garrison1
r.garrison1's picture

Here's some thoughts off the top of my head:

To see if the log is moving:

Maybe when you are cutting, set a short bit of a branch or something standing on end on the far end of the log (something sticking up that you don't mind knocking off when you get to it).

Watch the bit of wood, to see if it is moving a lot, or if it falls.

To see if a blade assembly adjustment may be the issue:

Check where the blade is riding on the wheels; if it is too far forward, the front edge may not be getting enough support.

Check the guides (if you use wheels); if they are too far back, again the blade may not be getting the support it needs. Also, see if the blade guides are in the correct place; they should not be pushing the blade out of it's normal trackm, but should just be touching it. I haven't used ceramics, but I believe they should be just off the blade, rather than touching.

To verify level:

With the saw off, get a 2X4 or something that you know is straight; lay it on the bed, lower the saw to just clearing the board by some amount you can easily recognize (1/8" may be good). slowly roll the saw down the track, watching to see if there is some spot where it jumps, changes, etc. I

 

If none of these help, then it is a real head-scratcher..

 

Post Oakie
Post Oakie's picture

There's some great ideas to file away for future reference.  I hadn't thought of the stick at the end of the cant trick or the 2x4 idea... brilliant!

DaveM
DaveM's picture

Thanx for the great ideas.  I have knocked the alignment totally out of whack & re-aligned the tracking.  I have the gullet set so it is just even with the wheels.  I also have a 96" aluminum straight edge.  I used clamps to secure it to the bed. It lays perfectly flush with the bunks.  I then set the blade height so it rode about 1/16 over the straight edge.  The saw head & blade remained a consistent height along the entire length of the bed. I also used the track alignment bar that came with the mill for installing the track rails.They are aligned & evenly spaced along the entire bed.  I have not yet had a chance to cut a log to see if these fixes work, but I did want to thank you for taking the time to pass them along.  Hopefully, I will set a log on the mill in the next few days & try setting a short section of  a dowel on the end of it for observation.  I will advise the results soon.  

DaveM
DaveM's picture

O.K. Gang....Here's the update.  The ground finally dried up enough so the tractor didn't tear the ground up around the mill today.  I loaded a beech log about 16" diameter on the mill.  The results were a major improvement over before.  I still had a dip or 2 in the log, but no where near or as severe as what it was.  I varied the speed that I pushed the carriage & the results were the same, fast, slow & in between.  I guess I will play with the blade guides a bit more to see if that helps.  The mill always cut very straight & consistent with the only "dips" occuring when cutting through a knot.  Like I said...I have the blade tracking so the base of the gullet is even w/ the rubber on the wheels.  Does that seem to be about right ?

eddiemac
eddiemac's picture

I think it's normal for the blade to deflect when hitting something harder than the rest of the log, such as a knot. I hear people complaining about that on certain softwoods.  A more troubling problem is when after entering the log the blade dives (or rises) and stays there until the end of the cut.  Then you know you have a blade problem.  Your tracking setup sounds correct.

DaveM
DaveM's picture

AND.....an update to the never ending saga.  The YouTube video on Norwood Sawmill School where the venerable Dave Boyt shared that little nugget about using a single spirit level on the blade to verify the tracking accuracy was a HUGE help in elimiinating the dipping / wavy cuts.  It made a BIG difference.  However, when the symptom reoccured I decided to reposition the ceramic guides.  It was then that I found the last gremlin sabotaging my mill !!  Somehow, both of the rear ceramic guides managed to wear on a 45 degree angle from bottom to top.  When I would set the blade guides so the blade was about 1/8" from the back of the blade it really made no difference since when the blade would contact the rear guide, the back would ride up the angle on the guide & cause the blade to dive.  Since I reversed the guides, having the back now be the contact point on the blade, I have had zero problems with "wavy" cuts.  Hope this will help someone out !!

Bill
Bill's picture

Rather than centering the log you could try leveling the log to the saw bed for the first cut in order to cut with the grain ?

Post Oakie
Post Oakie's picture

"I have the blade tracking so the base of the gullet is even w/ the rubber on the wheels.  Does that seem to be about right ?"

If is cutting straight, it is about right. You shouldn't have to accept a dive when you go through a knot, but you do have to slow down to allow the blade to transition from rip to crosscut and back to ripping.  If anything, you might want to track the blade forward a bit on the bandwheel.  When you find a log with a knot that makes the blade dip, try moving the tracking before you make the next cut.  If the dip is worse, try tracking it the other way.  Generally, too far back tips the blade down, and too far forward tips the blade up.  Pain in the neck to work out, but once you do, you'll have the solution.

DaveM
DaveM's picture

Here is a better late than never reply:  I was on youtube watching Norwood Sawmill School episodes.  You, Sir, had a tip on there that totally eliminated the problem.  Your idea of using a small spirit level on the blade when tensioned to verify the tracking was / is correct is genius & I would venture foolproof.  That & ensuring the bed is level have eliminated the wavy cuts for me.  Kudos !!

eddiemac
eddiemac's picture

The HD36 sounds very finicky.  My LM2000 is more user-friendly.  I wonder what they gained in performance by devising this more complicated design?  (Been thinking about that since I heard about the early blade guide complaints).

r.garrison1
r.garrison1's picture

I just came back from a bit of cutting in Eastern Oregon, and I had a problem with wavy boards too on my LM29.

I checked my guide rollers, and the lead one (the one that gets dripped on) had a bit of wobble. I didn't have an opportunity to replace it, so I swapped them (now that I'm home, I'll order the replacement).

It made quite a bit of difference.

I tried changing blades, adjusting the wheels, etc. Only changing the guide roller made a significant difference.

DaveM
DaveM's picture

Got out & basically removed the ceramic blade guides & switched them around.  They didn't look too bad.  Anyways...after playing around for quite a while adjusting them, it now seems to be cutting much better.  So...basically, I knocked everything out of whack & did a total new setup & calibration.  That made it hard to pinpoint if there was actually one element causing the wavy cuts.   Thanx to all for taking the time to offer all the possibilities to fix the problem.

kdm536
kdm536's picture

Hello everyone and thanks for all of the recommendations.   I set-up my HD36 and was cutting a dead oak tree than I had just felled.  Cuts seemed straight at first but then after about the second cut encountered the same wavy cuts.  At the time, I noticed a darker section of the wood where the waving began so I chalked it up to the blade hitting a dryer section of the log.... only to find that the waves continued on other cuts.   Adjusting the tension and the guides helped, but I can't seem to get a straight cut now (everything is level).  I am using a new Cobalt blade, so don't want to just toss it (expensive), but I do notice a slight crease (not really a bend) in the blade in one section.  Like I said this was pretty much my first tree and hadn't thrown the blade or anything else that would have caused this crease.... could it be a faulty blade, and if so, how is Norwood for working with you on these things...OR is there a way to get the crease out (it doesn't seem to be bad, just noticable).

DaveM
DaveM's picture

Sorry...I hit send a bit too soon.  Perhaps you should try a complete recalibration as I did.  Although there are some really great suggestions in this thread, (I tried them all), I did not resolve the problem until I knocked everything out of whack & reset everything.  I am definitely seeing better results since.  I think the vast majority of problems are not the mill's fault but operator errors.

DaveM
DaveM's picture

Sorry...I hit send a bit too soon.  Perhaps you should try a complete recalibration as I did.  Although there are some really great suggestions in this thread, (I tried them all), I did not resolve the problem until I knocked everything out of whack & reset everything.  I am definitely seeing better results since.  I think the vast majority of problems are not the mill's fault but operator errors.

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