At a loss with sawmill

[BT9212]

I have posted on here before having similar issues that are reappearing seemingly overnight with no real rhyme or reason. I have my mill, push style that I have converted to power feed. It's 27 foot long and a tad bit over 4ft wide. It was built by a local company. They have come out a few times and the response is basically that i'm getting as good of a cut as one can expect. I call BS on that since I have had repeatable perfect cuts. My main problem is my blade seems to be curving. I'm talking over an inch when the blade exits the log. It enters log, slowly curves up on each side against the roller bearings and as it exists it pops down. Blade is not getting too hot, tension is not slipping at all. My first thought was bad blade, replaced it and the same thing happened. Checked tension with a meter it read to approx 30k psi which is just under 3k on my mills reading so tension for a woodmizer double hard blade should be good, it's the tension I have always run. I have a video of it dropping but will need to go reread rules to make sure I can upload a youtube video. I have checked the roller bearings for flat spots and none are jumping out at me, it rolls free and smooth but I did notice it get gummed up and stop for a second on a cut. ThT shouldn't explain my issue though since it's still exerting downforce. Blade is level, might be an 1/8" off favoring drive side but that is also not new. Blade is also level to bed. Motor is full blade no slowing or stopping and I have my feed rate at 50% which is what I had it at for perfect cuts. I have reduced that down to 10% with the same results.













https://youtu.be/oXj9UdURjSM?si=Vl-X1DLH4pK3qIp0


https://youtube.com/shorts/SkZJCVs7ieM?si=Zj7fA_sAnbdYT6kK

https://youtube.com/shorts/MlOeXn8zTgg?si=H11AiSZeF96FbaLG

[Dave Shepard]

How is the drive belt tension? That is something that sneaks up on me sometimes. Could the teeth be touching a guide roller, knocking the set out of one side. Just WAGs. I hate being told "it's rough sawn", when I know what my mill can do. Good luck.

[BT9212]

How is the drive belt tension? That is something that sneaks up on me sometimes. Could the teeth be touching a guide roller, knocking the set out of one side. Just WAGs. I hate being told "it's rough sawn", when I know what my mill can do. Good luck.

I am hearing a little slap from it on guard but nothing crazy, I prob need to add a tensioner to it. It's built without a tensioner you have to roll the belts on. I'll definitely replace them and try that

[barbender]

Drive belt slippage will absolutely do that.

[WV Sawmiller]

    What are you sawing? You mention gumming up so I suspect yellow pine. If so what does it do with other kinds of wood like oak, maple or poplar or such? I'd address that gumming issue too. May need a diesel wiper or such to keep the blade clean.

  Are the teeth getting knocked out of set on the top or bottom? I had a blade hit a guard and immediately started climbing.

[SawyerTed]

That's a pretty nice mill to have been a locally fabricated mill.  I'm with you, it should cut flat.  

Drive belt tension is the first thing to eliminate.  The appearance is the variations are due to drops in blade speed possible because of slippage of the drive belt.  

Maintaining blade speed is a function of torque, what motor is on the mill?  Is it in top tune?  Does it bog at the variations?   If the cuts are flat everywhere but the ends, then it's probably the belt.  

Does the mill have an adjustable blade guide arm on the idle side?  It seems like a big space between the cant and what guide is there.  That guide should be very solid and stable, no slop or wiggle.  On a wide mill, the stability of the guide arm is extremely important and adjusting it to a couple of inches from the cant makes a difference.  

Try bumping up the blade tension a bit.   On a Woodmizer LT50 Wide the manual says 2,800 - 3,000 psi on the tensioner.  I find that maintaining 3,500 + saws better.  

[customsawyer]

What blade profile are you using? With that mill I would probably recommend 4 degree blade. Keep the blade clean. Even if you have to get a spray bottle and just squirt a little diesel on it. How much down pressure do you have on the rollers? Try a new blade, blade tension, drive belt tension. When you get some wear on your blade guide rollers they will start to become "cone" shaped. Check that your rollers are still parallel to the bed. 

[BT9212]

What are you sawing? You mention gumming up so I suspect yellow pine. If so what does it do with other kinds of wood like oak, maple or poplar or such? I'd address that gumming issue too. May need a diesel wiper or such to keep the blade clean.
  Are the teeth getting knocked out of set on the top or bottom? I had a blade hit a guard and immediately started climbing.

Using a mixture I found online, it's 1g diesel, 2 gallons water and a few drops of dish soap. It's pine I have not tried oak in a while but I do have some stacked I can try

[BT9212]

What blade profile are you using? With that mill I would probably recommend 4 degree blade. Keep the blade clean. Even if you have to get a spray bottle and just squirt a little diesel on it. How much down pressure do you have on the rollers? Try a new blade, blade tension, drive belt tension. When you get some wear on your blade guide rollers they will start to become "cone" shaped. Check that your rollers are still parallel to the bed. 

Using 10 degree double hard woodmizer blades, .45 thickness 158" length. Rollers are still parallel. My first thought was maybe one got gummed up and got a flat spot but I can't see one, doesn't mean it's not there I just don't see it. It's got about an 1/8" of down pressure

[BT9212]

That's a pretty nice mill to have been a locally fabricated mill.  I'm with you, it should cut flat. 

Drive belt tension is the first thing to eliminate.  The appearance is the variations are due to drops in blade speed possible because of slippage of the drive belt. 

Maintaining blade speed is a function of torque, what motor is on the mill?  Is it in top tune?  Does it bog at the variations?   If the cuts are flat everywhere but the ends, then it's probably the belt. 

Does the mill have an adjustable blade guide arm on the idle side?  It seems like a big space between the cant and what guide is there.  That guide should be very solid and stable, no slop or wiggle.  On a wide mill, the stability of the guide arm is extremely important and adjusting it to a couple of inches from the cant makes a difference. 

Try bumping up the blade tension a bit.   On a Woodmizer LT50 Wide the manual says 2,800 - 3,000 psi on the tensioner.  I find that maintaining 3,500 + saws better. 

The motor is an 18 horse DuroMax motor, running in top shape, I run her full throttle and never notice any bog, I run it pretty slow through the logs to allow the teeth to get clean with the line. It has an adjustable roller on the right it's all the way out currently. I can open it up but that opens it to nearly 30". It does seem to have some play if I really push and pull on it but nothing new. I have considered welding it in place since it's bolted on. They bolted it so you could add washers to give more down pressure if desired, the drive side roller can be raised or lowered. I do wish the idle side could be moved in closer to cant. At this point I'm so frustrated i'm temped to just sell it but I don't want to screw the next guy over.

[customsawyer]

I did a lot of sawing back in the day with 10 degree blades. I'm really grateful I don't have to use them any more. Get some 4 degree blades. Keep them clean and you might even need to speed up a little. You might be going so slow that the sawdust is spilling over your gullet and giving you poor cuts. Try sawing faster and you will get probably get better results.

[YellowHammer]

I have had entire boxes of brand new blades with poor set and they will do exactly as you are showing, measure the set, even a few thousandths will make a huge difference.  In the future, if you get a "gold sawing" band, take it off, store it, and use it as a reference if you ever have problems again to determine of the new problem is the band or the mill.

You are certainly going way too slow, and are packing sawdust as evidenced by the hard packed "spackle" on the tops of the cant.  A band cannot run straight with packed sawdust.  Your band has about 24 thousandths of set each side, and among other things, that set is designed to allow clearance between the sawdust and the body of the band.  So if the sawdust gets thicker than the width of the set, then it gets packed down and steers the band.

What have you adjusted the alignment of the band with a blade guide alignment tool, or similar?  It needs to be dead flat.  

Is your band dead clean?  If not, it needs to be.

Although it is not a Woodmizer, if I was there, these are the things I would check, and what I have found to be the most common causes of issues with other people's (and mine) in the past.  It might help.

 

[jpassardi]

As Jake said, I'd speed up your feed so you're not making powder and trapping it in the gullets. You want to feed as fast as your torque will let you. If you feed hard it should bog the engine, that will verify if the drive is slipping.
I would definitely stiffen up the adjustable arm.
Edit: Robert posted while I typed mine.

[BT9212]

I have had entire boxes of brand new blades with poor set and they will do exactly as you are showing, measure the set, even a few thousandths will make a huge difference.  In the future, if you get a "gold sawing" band, take it off, store it, and use it as a reference if you ever have problems again to determine of the new problem is the band or the mill.

You are certainly going way too slow, and are packing sawdust as evidenced by the hard packed "spackle" on the tops of the cant.  A band cannot run straight with packed sawdust.  Your band has about 24 thousandths of set each side, and among other things, that set is designed to allow clearance between the sawdust and the body of the band.  So if the sawdust gets thicker than the width of the set, then it gets packed down and steers the band.

What have you adjusted the alignment of the band with a blade guide alignment tool, or similar?  It needs to be dead flat. 

Is your band dead clean?  If not, it needs to be.

Although it is not a Woodmizer, if I was there, these are the things I would check, and what I have found to be the most common causes of issues with other people's (and mine) in the past.  It might help.

 

I'll watch that video and trouble shoot with it, I'm checking band alignment with a paper thin magnetic level, I don't have a cooks style clamp on but I may need to get one. I'm for sure going to add a belt tensioner somehow to the drive belts this weekend. I'll see what I can come up with in that regard, I had looked at adding an alternator anyways as that stator doesn't like to keep up the best. I'll also increase the speed, I assumed, mistakenly that slowing it down would allow the sawdust more time to get clear of cut.

[jpassardi]

If you're cutting pitchy pine, I suggest you add a diesel felt dripper. Set it to about a drip a second. I added a Cook's one to my Woodmizer on the blade infeed side. As noted above, get a refillable/high pressure rated spray can and put diesel in it as well for stubborn pine sapwood.
Knotty pine is the most difficult to cut without waves if the blade isn't sharp and set dead on.
Check out all of Robert's videos on Youtube - quality content.

[Ben Cut-wright]

Your blade is being *pushed into the cut by the drive wheel. 

The point of blade lube application makes it hard to overcome the sawdust.

That adjustable roller guide arm should be upgraded to more travel and there shouldn't be ANY play in the unit.

1/8" down pressure doesn't apply much friction between the rollers and the blade. 

What do you mean by "1/8" off favoring drive side"?

Your drive belt appears to flop even at the small diameter drive pulley.  If the belt can be heard striking the guard it is certainly too loose. Can't imagine there is NO method of initial belt tension upon install.

10 degree tooth angle should cut the cant widths you show.  4 degree might mask other problems without actually solving anything. 

Adjust forward travel until the engine shows the governor has taken over the throttle.  That won't be possible or likely to help until the other faults are corrected. 

[BT9212]

Your blade is being *pushed into the cut by the drive wheel. 

The point of blade lube application makes it hard to overcome the sawdust.

That adjustable roller guide arm should be upgraded to more travel and there shouldn't be ANY play in the unit.

1/8" down pressure doesn't apply much friction between the rollers and the blade. 

What do you mean by "1/8" off favoring drive side"?

Your drive belt appears to flop even at the small diameter drive pulley.  If the belt can be heard striking the guard it is certainly too loose. Can't imagine there is NO method of initial belt tension upon install.

10 degree tooth angle should cut the cant widths you show.  4 degree might mask other problems without actually solving anything. 

Adjust forward travel until the engine shows the governor has taken over the throttle.  That won't be possible or likely to help until the other faults are corrected. 

Yeah there's no tension device, i'm going to add one, it has always been that way but could have a stretched belt, i'll take care of that and hope it's the issue.

[RAYAR]

What blade profile are you using? With that mill I would probably recommend 4 degree blade. Keep the blade clean. Even if you have to get a spray bottle and just squirt a little diesel on it. How much down pressure do you have on the rollers? Try a new blade, blade tension, drive belt tension. When you get some wear on your blade guide rollers they will start to become "cone" shaped. Check that your rollers are still parallel to the bed. 

Using 10 degree double hard woodmizer blades, .45 thickness 158" length. Rollers are still parallel. My first thought was maybe one got gummed up and got a flat spot but I can't see one, doesn't mean it's not there I just don't see it. It's got about an 1/8" of down pressure

Ideally, the downward offset of the blade support rollers should be closer to 1/4".  I also see this mill is a push blade build rather than the pull blade set up. This means that the driven band wheel is pushing the blade rather than pulling the blade through the cant. These are more prone to the problems you seem to be having. You may need a higher blade tension to help counter the problems with blade push set ups. Also, is your blade being pushed back against the blade support roller stops when sawing? It should not be. The blade should not ride back if everything is properly aligned and blade tension is sufficient while sawing. Hope you get it figured out.

Ray

[BT9212]

What blade profile are you using? With that mill I would probably recommend 4 degree blade. Keep the blade clean. Even if you have to get a spray bottle and just squirt a little diesel on it. How much down pressure do you have on the rollers? Try a new blade, blade tension, drive belt tension. When you get some wear on your blade guide rollers they will start to become "cone" shaped. Check that your rollers are still parallel to the bed. 

Using 10 degree double hard woodmizer blades, .45 thickness 158" length. Rollers are still parallel. My first thought was maybe one got gummed up and got a flat spot but I can't see one, doesn't mean it's not there I just don't see it. It's got about an 1/8" of down pressure

Ideally, the downward offset of the blade support rollers should be closer to 1/4".  I also see this mill is a push blade build rather than the pull blade set up. This means that the driven band wheel is pushing the blade rather than pulling the blade through the cant. These are more prone to the problems you seem to be having. You may need a higher blade tension to help counter the problems with blade push set ups. Also, is your blade being pushed back against the blade support roller stops when sawing? It should not be. The blade should not ride back if everything is properly aligned and blade tension is sufficient while sawing. Hope you get it figured out.

Ray

I don't think it's possible to get 1/4" on this mill, the idle side is fixed but I have looked at the cooks add on version that's got adjustments I may add. The blade is not touching the back of the roller that I have seen. I have it to where the blade is centered on the wheels. I will see if I can get more down pressure

[fluidpowerpro]

@BT9212, you mentioned that you have a DuroMax engine. How has it worked for you? I'm considering putting more HP on my mill but am afraid of using anything other than a name brand.

[BT9212]

@BT9212, you mentioned that you have a DuroMax engine. How has it worked for you? I'm considering putting more HP on my mill but am afraid of using anything other than a name brand.

It's been great, it's a few years old and still going strong. I would get bigger if I ever upgrade. 18 HP cuts strong but I would want more

[DanielW]

I'd agree with all those who said to check drive belt tension. Even a small, imperceptible bit of slippage from a belt that's slightly stretched will cause the blade to lift, dish, dive, duck, and do all sorts of other funky behavior. Most smaller-section v-belts used on mills like this will stretch pretty easily and regularly. And it's very concerning that you're able to roll the belt into the grooves. If you're able to roll a belt into the grooves and there's no tensioner, I can almost guarantee the belt's too loose.

But another thing to check: How often is the mill frame supported, and is it levelled up properly with regular supports? Hard to tell from the pictures. It looks like a well-built mill, but the frame rails appear to be only 3" (maybe 4"?) channel with the guide angels welded to the top. Which is plenty strong enough if regularly supported, but if you only have full positive contact with your supports/legs at a few spots near the ends, it could definitely be flexing in the middle with a heavy log and the weight of the carriage on there. A little bit of frame rail flex will cause the blade to track pretty funky as the carriage travel will prescribe an arc through its range of motion. A few locals near me have had me come out to look at their problems. In both cases they had economy Woodland Mills setups without the trailer package, Without the trailer package, those frames are pretty flexible and need proper levelling with several regular, solid supports or they'll flex a little and cause grief.

[jpassardi]

@BT9212, you mentioned that you have a DuroMax engine. How has it worked for you? I'm considering putting more HP on my mill but am afraid of using anything other than a name brand.

My personal experience: I upgraded from 15 to 25 HP, both Kohlers. It made a considerable difference especially in wide cuts. I wouldn't want less.

[Nebraska]

I had similar problems with  13 hp Honda on my original ez boardwalk jr. I went to only 4° blades. I did put a new drive belt on it and used straight diesel fuel as a slow drip. It the issues of blade rising the cut got better. Knotty dry hardwood was part of the issue.  Now if I have an issue with my Timberking it's mostly a bad blade issue  or an operator's error. I hope to run it today for a while 

[BT9212]

I'd agree with all those who said to check drive belt tension. Even a small, imperceptible bit of slippage from a belt that's slightly stretched will cause the blade to lift, dish, dive, duck, and do all sorts of other funky behavior. Most smaller-section v-belts used on mills like this will stretch pretty easily and regularly. And it's very concerning that you're able to roll the belt into the grooves. If you're able to roll a belt into the grooves and there's no tensioner, I can almost guarantee the belt's too loose.

But another thing to check: How often is the mill frame supported, and is it levelled up properly with regular supports? Hard to tell from the pictures. It looks like a well-built mill, but the frame rails appear to be only 3" (maybe 4"?) channel with the guide angels welded to the top. Which is plenty strong enough if regularly supported, but if you only have full positive contact with your supports/legs at a few spots near the ends, it could definitely be flexing in the middle with a heavy log and the weight of the carriage on there. A little bit of frame rail flex will cause the blade to track pretty funky as the carriage travel will prescribe an arc through its range of motion. A few locals near me have had me come out to look at their problems. In both cases they had economy Woodland Mills setups without the trailer package, Without the trailer package, those frames are pretty flexible and need proper levelling with several regular, solid supports or they'll flex a little and cause grief.

I have a 4ft deep pillars below each bunk on both sides, frames not dipping. I did have that issue when I first started though. I had to build the pillars and I'd like to move to concrete