For those of you that set your own teeth...

[chaikwa]

What are you setting them at? I just set up a tooth set on my manual sharpener so I can adjust the set just prior to sharpening and just to see what would happen set them at .030". Makes the blade cut like butter but leaves WAY too much sawdust.

So before I just 'tried' another setting, say like .020", I'd ask someone who is already doing their own set.

Thanks!

 

[hamish]

It all depends upon what you are milling. Softwoods such as pine and spruce I am going with 25-28 per side, if frozen 21-24. Most hardwoods between 18-21. Set is very dependant upon the spcies, diameter and at times the individual tree.

 

[BobL]

What are you setting them at? I just set up a tooth set on my manual sharpener so I can adjust the set just prior to sharpening and just to see what would happen set them at .030". Makes the blade cut like butter but leaves WAY too much sawdust.

So before I just 'tried' another setting, say like .020", I'd ask someone who is already doing their own set.

Thanks!

Setting the "teeth" or using the more technical term "rakers" for efficient cutting has a bit more to it than most folk think. Fixed heights like 0.030 or 0.020" are OK when the chain is new but far from ideal when the chain becomes used. Instead of focussing on a fixed raker height operators should consider fixed raker angles, that's the angle between wood, cutter edge and raker top.

A very simple way to do this is to use a file-o-plate (FOP) or similar type guide but I find these are too wussy since the produce raker angles of around 4.5º whereas around 6 or more degrees works better.

A simple way to work out what raker height to set to obtain a raker angle of 6º is to measure the cutter gullet with a set of calipers and then use 1/10th of that as the raker depth. for a new 3/8 chain the gullet is typically 0.25" so using 0.025" raker depth makes sense but when the cutter is old the gullet might be 0.5" so to maintain the same cutting angle a raker height of 0.05" needs to be used.

For a more geeky an technical discussion about raker angles and FOPs see here.

FWIW I use 6.5º raker angles on most of my chains.

 

[hamish]

Bandbaldes or sawchain?

To the OP, which teeth are you referring to?

 

[bobt]

Setting the "teeth" or using the more technical term "rakers" for efficient cutting has a bit more to it than most folk think. Fixed heights like 0.030 or 0.020" are OK when the chain is new but far from ideal when the chain becomes used. Instead of focussing on a fixed raker height operators should consider fixed raker angles, that's the angle between wood, cutter edge and raker top.

A very simple way to do this is to use a file-o-plate (FOP) or similar type guide but I find these are too wussy since the produce raker angles of around 4.5º whereas around 6 or more degrees works better.

A simple way to work out what raker height to set to obtain a raker angle of 6º is to measure the cutter gullet with a set of calipers and then use 1/10th of that as the raker depth. for a new 3/8 chain the gullet is typically 0.25" so using 0.025" raker depth makes sense but when the cutter is old the gullet might be 0.5" so to maintain the same cutting angle a raker height of 0.05" needs to be used.

For a more geeky an technical discussion about raker angles and FOPs see here.

FWIW I use 6.5º raker angles on most of my chains.

BobL.

That is the simplest and most usable explanation of progressive raker heights that I have ever seen here on AS.

1/10 of the gullet. I will remember it always. I have used the file-O-Plates in the past, and liked the results, but your simple formula of 1/10th of the gullet is golden! I will use it from now on!

Thanks

Bob

 

[chaikwa]

To the OP, which teeth are you referring to?

The ones that do the sawing on a band blade. Every third tooth is a 'straight' tooth with no off-set. The other two are 'bent', for lack of a better word, left and right. I'd like to know the AMOUNT of off-set to set the teeth.

I am sawing all hardwoods, mostly oak, maple and some cottonwood, tho that's hardly 'hard'.

Thanks!

 

[hamish]

Whats the band pitch (ie 7/8, 3/4") length of the band and the amount of hp driving the mill?

For hardwood you will want to be setting your teeth with a much lower set than 30.

What type of mill have you got and type of setter/sharpener?

 

[VA-Sawyer]

Here is what I have learned from sharpening my own band blades for my 25 HP Woodmizer for the last 8 years:
More set means more power required and more sawdust produced but seems to be more resistant to climbing and diving problems. The tendency to cut straight becomes more noticable as the blade dulls or as the difference in hardness between the sapwood and knots increases.
The first couple of years of sharpening, I spent a fair amount of time experimenting with hook angle, set and gullet size. All three are related to hardness of the wood, width of wood and feed rate. Tooth pitch is also a big factor, but not one you can really change during sharpening.

To start with, the harder the wood the less hook angle I use. This can vary from 4 degrees for frozen logs, dry Pecan or Hickory, all the way to 14 degrees for fresh wet Yellow Popular.
Lower hook angles mean lower max feed rates for a given blade speed. Higher feed rates allow more board feet cut between sharpenings. However, higher hook angles have less durable edges, so they dull faster. Match the hook to wood hardness .

The set is mostly determined by how much flex the wood fibers have. As the tip of the set tooth cuts, it also tends to crush and deflect the wood fibers. ( think of cutting a wet sponge ) The actual cut made by each tooth is less than the set would suggest, as the deflected wood fibers stand back up after the tip passes. Note: The actual Kerf is wider than the set would predict due to blade vibration, but not important to this explanation. The set must be enough to keep the fibers from touching the blade after they flex back to the straight position. You want the minimum set that will provide the required clearance as this will require less horsepower. I tend to set my teeth at .015 for dry wood, .018-.019 for pecan to White Oak, .020-.021 for Red Oak to Beech and .022 for Pine and fresh Yellow Popular.

The third factor is the gullet size which is related to tooth depth. The smaller the gullet, the stronger the tooth for any given tooth shape. The down side is, the smaller the gullet, the less sawdust it can carry. If you increase feed speed, or increase set, you will get more sawdust per inch of blade travel. The wider the log, the more sawdust each tooth produces as well, as it is cutting for a longer length before exiting the wood. You do not want the gullet to fill with sawdust before the tooth clears the wood, as the packed sawdust will tend to keep the tooth from penetrating in the foward direction. The feed speed goes down and friction goes up. If the kerf is wide enough, the excess sawdust can spill back onto the blade body and is packed against the cut wood surface. This means that wood fiber is pressing against the body of the blade which creates heat and even worse, tends to steer the blade up or down causing a wavy cut. You can make the kerf even wider so the excess sawdust has room, but this produces even more sawdust and requires more HP. This is part of how the higher HP saws can get so many bf out of a sharpening. They have the power to run more set, which allows the blade to get duller before tracking becomes an issue. I go to a deeper gullets rather than wider sets on wide boards, but I 'm limited by tooth geometry.

The tooth pitch determines the maximum gullet size you can get and still have a tooth profile that will hold up in terms of stiffness and durability. Wider logs really need teeth with more pitch to have good feed rates. Of course, narrow cuts require less tooth pitch in order to keep 'at least 3 teeth in the cut' as per the old rule of thumb for pitch, so it means we should be changing our blades when going from wide cuts to edging boards. No, I don't do it either, but I do at least understand why I have to slow down the feed so much on wide cuts, and Yes, I do wish I had some blades with big pitch for those really wide logs that seem to take forever on each pass.

Everything is a trade off! The goal is to balance the 3 sharpening factors you can control, to get the fastest feed rate that will produce an acceptly flat board and run the longest before needing to be resharpened. You will need to do a little experimenting to find what works best for your saw and brand of blades. If I had 50 or 60 HP on my mill, I would likely increase my sets by around .005 and maybe increase my hooks by one or two degrees as well.
Good Luck,
Rick

 

[BobL]

BobL.

That is the simplest and most usable explanation of progressive raker heights that I have ever seen here on AS.

1/10 of the gullet. I will remember it always. I have used the file-O-Plates in the past, and liked the results, but your simple formula of 1/10th of the gullet is golden! I will use it from now on!

Thanks

Bob

Thanks Bob.

Apologies to the OP for thinking that they had confused "set" with "raker height" and "bar" with "blade" etc. I have been replying to too many posts on another forum where newbies refer to bars aasnd blades etc.

 

[chaikwa]

Whats the band pitch (ie 7/8, 3/4") length of the band and the amount of hp driving the mill?

For hardwood you will want to be setting your teeth with a much lower set than 30.

What type of mill have you got and type of setter/sharpener?

7/8", 153" and 15 hp. I made my own mill from plans by Linn. I also made my own sharpener and setter.

Here is what I have learned from sharpening my own band blades for my 25 HP Woodmizer for the last 8 years... Rick

Wow! Thank you SO much for the very detailed explanation! Lots of great info there I will put to good use!

Apologies to the OP for thinking that they had confused "set" with "raker height" and "bar" with "blade" etc. I have been replying to too many posts on another forum where newbies refer to bars aasnd blades etc.

No apologies needed. I appreciate you taking the time to reply. I used to use a chainsaw mill when I first started and when I built it, I had a bandsaw in mind for the future and made the track so that I could use it with the bandsaw. There was a lot of good info in your post that I hope someone will see and be able to use with their chainsaw mill. Most of it I already knew from reading posts by other people like yourself that knew what they were talking about and how to effectively convey it, but I still learned a few things I didn't know. Thanks again!

 

[chaikwa]

A little update...

I figured I'd try a Munksforsagar(sp?) blade, both to try it because I've heard good things about them and also to have a new, never used blade to see what it would have it's teeth set at. Well, I haven't sawn with it yet, but I put it on the sharpener/setter and I'm kinda disappointed. There isn't as much tooth as the Lennox blades I've been using. The gullet isn't as deep leaving less tooth to wear down. As far as set goes, one side was set at .021" and the other side was set at .018". I'm not sure if this is correct or not, but it kinda defies common sense unless there's something I'm missing. I would think the set should be the same from side to side.

Any thoughts?

 

[hamish]

How many teeth did you check the set on per side? How was the Munksforssager band shipped to you, coiled or uncoiled, if in a box how many were there? Banda can take a beating in shipping, as you have your own setter it doesn't hurt to set them before use.

Compare apples to apples and ensure both bands (munks and lennox) are of the same hook/pitch etc...

Lenox bands are supposively a little thicker in the body due to them being built on metric scale (if you hear this its bull..........slop. Almost all bands are manufactured outside of north america...so they are all built on a metric scale.........regardless of the reasoning the Lenox woodmaster c's are a lil wider in the body than most bands).

 

[VA-Sawyer]

Woodmizer claims to make their own blades. I saw the factory for new blades in Indy back in 2003.

 

[chaikwa]

How many teeth did you check the set on per side?

All of them.

How was the Munksforssager band shipped to you, coiled or uncoiled, if in a box how many were there?

Coiled, in a box, just one. I wanted to see/try one before I went crazy and got a bunch of them.

Banda can take a beating in shipping, as you have your own setter it doesn't hurt to set them before use.

I did. Set them all to .020" as this seemed like what they were going for. Some were .020", some .021" and some as much as .024"

Compare apples to apples and ensure both bands (munks and lennox) are of the same hook/pitch etc...

I ordered it to the same spec's as the Lenox bands I've been using just so I would be able to compare equally. Like I said, I haven't sawn with it yet tho.

Lenox bands are supposedly a little thicker in the body due to them being built on metric scale (if you hear this its bull..........slop. Almost all bands are manufactured outside of north america...so they are all built on a metric scale.........regardless of the reasoning the Lenox woodmaster c's are a lil wider in the body than most bands).

I haven't put either of them in a micrometer yet, but that's a good point. The Munks are supposed to be .041" while the Lenox are supposed to be .042".



On a totally separate topic; anyone have any ideas how to keep mice out of the engine? I have my mill set up so I can roll the headrig into its' own little shed to keep it out of the weather and the mice seem to find every nook and cranny in and around the engine. Even the cooling fins on the head have turned into little mouse condo's. I've put sticky traps, bait boxes and even moth balls all over the engine wherever I could shove them as well as all around the interior of of the shed and I still find the stoopid little things. They chewed thru the charge coil wire INSIDE the flywheel as well as the grounding wire for the ignition coil.

You can see the shed on the far end of the mill in this pic;

 

[hamish]

I like your shed for the powerhead!

The only thing I have seen that works well for mice is a hungry cat.

 

[VA-Sawyer]

Ditto on the cat. I also had a mouse problem when I moved here ,so I got a kitten from the guy that gave me my first chance to climb. Took about 6 to 8 weeks, and havent seen evidence of mice since. Just don't over feed the cat, hungry cats make better hunters.
Rick

 

[chaikwa]

We have a few cats in the barn that keep it relatively mouse-free, but they don't venture all the way out to the mill. We DO feed them a little bit, so I'm thinking of starting to feed them in the saw shed and see what happens. I can take the headrig off the mill and bring it inside, which is what I've done now to repair the mouse damage, but it's kind of a pain getting it lined back up on the tracks when I put it back on the mill. It's easy with 2 people, but I don't often have a second person to help me.