What am I doing wrong!?

[Stevenjohn21]

I've been frustrated for several weeks now because anything 12' or longer that I try to mill, I end up with a hump in the wood in just one place (about 4' into the cut)
I have adjusted the guides within a piece of paper away from the blade, the back wheel is the same however, whenever I get to this same spot on the mill, the blade wants to angle up and then a few inches later it starts to come back down and then levels off perfectly for the remaining cut.

If I move the guides any closer I can hear the blade rubbing on them, so I know I have them correct but somehow it's still cutting a mountain every time. 
I have a torque wrench set at 24 ft lb for the blade tension so I'm good there. 
The mill is a 130max 
 

[Wlmedley]

Sounds like a problem with your bunks.I would get a piece of masonry string and stretch from back bunk to front bunk with a one inch spacer under it on both ends.Then go to each bunk and measure.If not one inch adjust legs under rails.Check both sides.If bunks are all in line rails should be too but you might want to string them also.Hump in rails will transfer to your logs.

[WV Sawmiller]

   Also how stable is your support? I am not familiar with your mill but could the weight shifting cause the change? Running the string might indicate the bunks are in line but are you getting some sag at that spot? Getting a hump doesn't sound like sag but check anyway. 

   How about the track? Is it clean or is there some kind of build up on the track causing the rollers to raise up which would raise the head at that spot?

[YellowHammer]

These can be pretty hard to figure out.  So it's always doing it at the same place?  Then it's time to take to log off and mark where the hump is and hand push the mill down the track and especially pay attention to the area of where the hump forms.  Pushing the head by hand (engine off) will let you feel what the mill head is doing as it travels up and down the rail to see if it's rocking inboard and outboard, is it hanging, is it staying dead flat through the trouble spot.  Sometimes the rails aren't welded and lined up correctly and, it will cause the head to rock back and forth.  Our there is some crud built up on the rails that the bearings may be riding on, or any numbers of things.      

[Old Greenhorn]

Those 3 posts above are rock solid things that any experienced bandsawyer would begin with. Likely you have already looked into them, but you need to get really picky and look very closely. In any event, I can't add to what they said.
 However, I would like to get some more detail on the problem that might help us find something. You said anything 12' or more gets this hump at the 4' mark. Does that mean an 8' log will have no hump?
 Also, you say it's in the same place (4' ) every time, but what happens if you move the head of the log forward or back, is it still 4' in on the log, or is it in the same place on the mill bed?
 It may sound like I am splitting hairs, but that's what you have to do sometimes to get a clue leading you to the solution.
 Don't get frustrated, focus on each detail as deep as you can. Write things down if you need to. Make no assumptions, check each thing completely. 
 Best of luck and we'll hang in with you until you figure it out. There is always an answer.

[Southside]

As much as this might not make sense a bad bearing may be the issue.  When I have had cam followers go out on a WM mill I have experienced bind up or other issues at the same travel point along the bed.  Would not bind up any other spot along the 20', but right at the same spot every time.  A cam follower is basically a bearing that laterally supports the mill head assembly and rotates plenty of times along the way, but likely due to tolerances, would only cause me issues in one spot.  

[bigblockyeti]

Is this happening even with a new blade?  I was cutting cherry last week and the new blade I started with was still cutting perfectly with zero signs of dulling after 400bdft.  Then I barely touched the second backstop with the blade and I knocked the tooth set from the entire bottom side of the blade.  It still cut well, just not straight, it wanted to go up like what you've shown.

[Stevenjohn21]

I have loosened the rail and tightened again making sure it was level with the rest of the bed. I also put a laser level on the bunks and lined up with the blade, moved the head down to each bunk and re-tested and all seems level since the laser was hitting the blade on each bunk. 
I have a woodmizer 7 degree blade in it at the moment which is brand new. 
I have only cut a few logs since owning the mill. I cut a small cherry about 14" in diameter and only 5' long and didn't notice any humps but I'm not sure where on the bed I cut it. 
I put a monster basswood 28" diameter x 14' long on to cut stickers and I noticed immediately the hump. 
I went cut it again and as I slowly approached the hump I could see the blade starting deflect up wards and begin making that hump so I stopped. 

[customsawyer]

I know it is a pain with your mill but if you can take the log off and turn it around. Cut it from the other end and see if you still have the hump in the same spot on the log or the mill.

[Old Greenhorn]

I don't mean to nit-pick here, but that's what you have to do sometimes to find the root cause.
 How many logs over 12' have you seen this on? Were they all in the same spot?
 You mentioned at the end of August in another thread you were getting wavy cuts in 20" basswood, hw did that finally turn out? Did you solve it?
 This is a large log. Is it possible that the leveling jacks in that area are taking more of the load and sinking a bit with the weight?
 Lastly, have you only cut one face on this log, or have you tried the other faces?
  It could be that you can do opening cuts on 4 faces, then do a cleanup cut on any faces that have a wave. More flipping, but good troubleshooting and I bet you learn something about the problem's behavior.
 Based on what you said in your last post, I would change out that blade first, before I did anything. If the new blade cuts the same, it's not that and you can use that other blade next time you swap out. But it's too easy to have a tiny blade defect from a previous log that you can't detect.
 Don't forget, you've only had this mill a short time and this is a necessary (and frustrating) part of learning how it behaves, how hook angles relate, lube flow, HP, cutting head speed, all play a part and all the other stuff too. It's a dance, with a lot of steps to learn.  ;D Keep yer chin up.

[Stevenjohn21]

Thank you for your advice. I really enjoy this hobby when all is working as it should and I get a sense of accomplishment at the end of the day but man, it's so frustrating when one tiny problem messes up everything! 

Yes, back in august I had wavy cuts. That was due to loose belt, loose blade and me messing with the drive side wheel which is all sorted now. The waves in this cut is around 4' from the start of the bed. So anything I put in that area will create a curve. It's like the bed isn't level however when I'm cutting I can physically see the blade start tilting up which makes me think it's the blade function. 
I'm not giving up and I know with everyone's knowledge on here I will be able to fix it. 

I have turned the log and tried to cut a fresh side but the exact same thing happens. This is the 2nd 12'+ log this has happened on. I'm trying to cut the basswood to make stickers so I need this to cut straight. 

[JRWoodchuck]

Seems like I remember other members having similar issues on the same mill and it ended up being one of the bearings or bushings that was faulty from the manufacturer. 

[Ljohnsaw]

Just trying to get a clearer picture.  You had troubles (that you noticed) on just the two logs?  Both were basswood?

Several years ago, my mill was cutting real good.  Put a fresh log on and just could not get it to cut straight.  It would dive in several places.  Take another slice and still dive in the same places.  I would back up (carefully!) the second I saw it diving and go slow to let the blade correct itself.  Made for some ugly wood.  Usually it would do it on one face and 180° as well but not at 90° - sort of tells me it's the grain of the log.  A couple logs later, same thing.  Only this time I tossed the log.  I've had a few logs that just don't want to be cut!  It happens.  Maybe too dry, maybe too stressed, maybe knots and cutting from "the wrong end".  I have 3 or 4 big logs with a couple faces opened sitting around.  Since they are pretty big, I make benches out of them - no need for legs - and no worries that someone will steal them since they weigh a few hundred pounds ;) :D

[btulloh]

Looks like blade tension and maybe sawing just a bit too fast right there. 

24lbs on the torque wrench is not an absolute. Sometimes it needs a little more. Different band types need different tensions. How thick is that band? .042, .045?  The torque setting is convenient but the only way to truly know is to measure the actual blade tension. Short of that, observations like blade flutter when running free, or tweaking based on results work for a lot of us. There are a lot of little things that affect cut quality and it takes time and experience - and a little frustration- to learn all of them. You're doing well and just going through the normal learning process. When everything is right the saw will make straight cuts. "Everything " is a pretty long list. Hang in there and don't be afraid to experiment. 

[jpassardi]

You may want to try a new blade on that same log in case the set or sharpness is greater on one side. If no change, then the new blade with more tension. If neither helps, flip the log endo to rule out grain.
If no change, it's likely a bed or carriage issue. If the carriage travels through the bed straight I'd check the guides. Do you have roller or pinch block guides?
Check one variable then the next. Hang in there - diagnostics can be a PITA but try to be patience and follow logic. Good luck.

[firefighter ontheside]

On my woodmizer the guides are meant to put down pressure on the blade and not just be adjusted to be close to the blade.  I guess that is not the case with woodland mills.

[Stevenjohn21]

You may want to try a new blade on that same log in case the set or sharpness is greater on one side. If no change, then the new blade with more tension. If neither helps, flip the log endo to rule out grain.
If no change, it's likely a bed or carriage issue. If the carriage travels through the bed straight I'd check the guides. Do you have roller or pinch block guides?
Check one variable then the next. Hang in there - diagnostics can be a PITA but try to be patience and follow logic. Good luck.

I have new 10 degree blade which I will try tonight (I've got a 7 degree on at the moment) 
My guides are the ceramic block style except the back one which is a roller. 

[Stevenjohn21]

I fixed the problem! 
Don't know how but after changing the blade, re-adjusting the guide blocks (ziplock bag distance away from the blade) and tensioning the blade one more turn than my 24 ft lb I made a cut and it's straight! 
I also learned that you can put a blade on wrong 🤦‍♂️ 

Thank you to everyone that gave me advice and gave me the patience to keep messing with it. 
I also apologize to my mill for calling it some pretty bad cuss words over the last few weeks! 

[bigblockyeti]

My bet is the tension probably helped out the most.

[jpassardi]

Good to hear you addressed the issue. Keep in mind, it's likely to reappear at some point.
It's another expense but you may want to upgrade to roller guides, Cook's sells them. When set properly they are 1/4" lower than the band wheels. This provides down pressure on the band closer (than the band wheels) to the cut.

[Southside]

How much clearance do you have between the back of the band and the rollers? 

[Don P]

One thing that is hard for me to do when I have the wrenches out is to only adjust one variable at a time between trying it out. If I change several variables and fix the problem, I'm not sure what the problem was.

I'm not a bandmiller but one thought came to mind. If the blade is in cut and the track or head drops even slightly, the tips of the teeth angle upwards in response.

[Stevenjohn21]

How much clearance do you have between the back of the band and the rollers?

Piece of paper thickness away 

[Stevenjohn21]

One thing that is hard for me to do when I have the wrenches out is to only adjust one variable at a time between trying it out. If I change several variables and fix the problem, I'm not sure what the problem was.

I'm not a bandmiller but one thought came to mind. If the blade is in cut and the track or head drops even slightly, the tips of the teeth angle upwards in response.

Yes, that is why I thought the blade adjustments were not needed. I was convinced it was the rail that wasn't level or square but turns out I was wrong.... Again 

[Southside]

Not sure what your mill calls for but 1/8"-1/4" of clearance is normal for mills with roller guides. This allows for some rearward travel of the band before it hits the flange as having the band in contact with the flange causes issues. 

[btulloh]

A business card thickness for clearance on the blocks and the same for the bearing behind the blade is perfect. Too little clearance on the ceramic blocks can lead to problems especially if you get a little pitch buildup on the blade. 

Yes, roller guides are better than blocks and some people have changed out the blocks for Cooks rollers, but you can saw good lumber with the blocks as it comes from the factory. These mills weren't designed for rollers. Changing to rollers is possible but it takes a little fab work to make it happen. 

Congrats on getting it worked out. All part of the normal learning process. 

Once a new mill gets a few hours on it, it'll need to be readjusted as things settle in. Belts will stretch, things move.  Just be aware that a mill is not a set it and forget it thing. Usually the throttle cable will stretch a bit and will need to be adjusted. You can lose rpm's gradually and not notice it. Don't want to lose rpm's. 

[thecfarm]

Glad you figured it out.
Happy sawing!!

[Old Greenhorn]

You may not believe us, but we all knew you would figure it out if you just hung in there. Things like blade tension, lube, speed, (getting the teeth facing in the right direction), hook angles, and all those other little associated things take time to figure out and balance for your setup. Then you get a different log species and it can start all over again.
 Notice how many guys told they that they too put a blade on backwards? Notice that they all thought it was funny when they did it and learned? If you can't laugh at your self, you may just go crazy. :D It's all part of the ride on this great sawdust dream.
 Myself, I have developed a lot of odd working habits to try and avoid repeating my bigger mistakes. I never send the head down the log that I don't check the backstops and clamp height. I never (well, almost never) roll a log without first putting or making sure the toe boards are down (still working on this habit). I have some other habits that are so developed that I don't even realize I still do them. All were learned after making a mistake or having an issue 2 or 3 times.
 The first time on the LT50 that the head stopped moving forward in a cut I went crazy trying to figure it out. A 28"x14' log, with the blade halfway down it, just stuck. I could not back up without popping the blade and I sure couldn't go forward. I was just about to shut it down for the day and go get help when I found that a piece of bark had fallen off the log and onto the live chain where it jammed up under the electrical box when it tried to pass over it. Took a little to get it out/break it up and I bet I lost 20 minutes before I was running again. But I admit, I felt pretty good that I figured it out and could cut the rest of the session. Now I look at the chain frequently out of habit when I am opening the logs up.
 It may sound silly, but when I am at the mill I get in a zen-like mode. Nothing in the outside world exists and I ignore all distractions to just focus on the work at hand. It is pleasure time and a time to create 'stuff'. You can also get hurt, so you need to focus on safe and efficient habits.
 You will get there, you already have a good start on the basics and have ticked a few things off on your training jacket. ;D

[RAYAR]

I have new 10 degree blade which I will try tonight (I've got a 7 degree on at the moment)
My guides are the ceramic block style except the back one which is a roller.

I would go back and try that 7 degree blade again with the increased tension and see how it does now.

I have a custom built mill with a spring tensioner and was shown where to set (a marking) the blade tension when I bought it. It didn't really take that much effort to cause the blade to roll back against the backing roller. After using it that way for a while, I increased the blade tension some and now it takes a lot of effort for the blade to roll back against the backing roller and I see much less waves in the cuts. My backing rollers now have no signs of the blade rolling back against them, the way it should be. My backing rollers are now black instead of polished steel where the blade would contact them.

[kelLOGg]

I'm a believer in setting band tension by actually measuring like Btulloh said. There's a lot about it on FF. 

[alecs]

I have the same mill and I use a an automotive feeler gauge to set the clearance of the guides.  I believe it calls for .020 above and below, and 0.040 behind.  I "fake it" by using say the .018 on one side and the .020 on the other side since they are all in a set and really designed to be used one at a time.  But I stick the two of them in together, one on either side of the blade, squeeze everything together, and tighten.  It's important that the weight of the feeler gage set, and the fingers of the operator, do not tweak the angle or spacing of the guide blocks when tightening, so I will tighten everything up and then check it again one side at a time when done.  I have no idea whether this is a proper technique, but when I read the manual and it said to try for those spacings above and below the blade, I remembered I had the feeler gauges and that's what I went for.  I can try to post a picture of this if it's useful.

When I have found wavy cuts, however, it is usually a combination of knots/grain and a dull blade.  Changing the blade usually fixes it.  One other thing - I had a thread a little while back about blade carnage.  The set of 10 woodland mills blades that I bought with the mill seemed to be always falling off.  So I bought some Woodmizer blades and had good luck with the blades not falling off.  But I still had a few of the Woodland blades left.  I tried one of those recently and it seems to cut better than the Woodmizers, at least in the pine logs I was cutting.  And it hasn't fallen off yet, knock on wood.  So while I originally thought it was the blades, it doesn't seem to be.

I agree, adjusting one thing at a time is difficult but necessary.