"Chattering" during bore cuts

[Frickman]

GASoline71,

I bore cut almost every tree I fell. I'd guess 95% of the trees over 10" I bore. The only exception is when I have a back leaner that I know I'm going to wedge over. Even some of them that are bigger I bore cut to set up the hinge. The real small stuff is harder to bore cut and usually I don't have a reason to so I'll just go from the back to the hinge. That's less than 8" on the stump.

The reason I bore cut is to prevent barber chairing. Look around the Forum and you'll see lots of information about that. It also is a more precise method of felling. I can take my time and setup my hinge so that it's perfectly uniform across the width. I then cut back and release the tree. It's hard to setup your hinge when you're racing the falling tree as you're making your back cut.

Kevin,

I'm running Stihl MS460's with the "wide" Stihl 20" bar and 3/8" square tooth full skip, round ground chain. This combination is the smoothest yet fastest cutting combination I have ever run in the woods. Sometimes I run a 24" bar in bigger timber with the same chain. This might have something to do with my ability to bore cut without kick back. I was thinking about it today, and I think some of what I'm doing is using the reactive forces that cause kick back to actually pull the saw into the tree. I know I expend less effort using the top of the nose than using the bottom of the nose.

[John Mc]

...I think some of what I'm doing is using the reactive forces that cause kick back to actually pull the saw into the tree. I know I expend less effort using the top of the nose than using the bottom of the nose.

Wouldn't the top of the nose tend to push you back out, rather than pull you in?

[Frickman]

John MC,

Yes, it will. And no, it won't. It depends on the angles of everything and how you're running the saw. I think that what I'm doing is actually "taming" those reactive forces and directing them to pull the saw into the tree. At least that's what it feels like I'm doing. Where other folks would have the saw kickback on them I have the saw pull itself into the wood. It''s real hard to explain here, it's easier to show you in person.

Several years ago I was logging a property adjacant to where a residential tree service company was doing some removals around a house. I got to talking to them over lunch and they said they had never heard of a bore cut. They said you can't bore the nose of the saw into a tree. After lunch I brought my saw over and bored into a snag they were getting ready to remove. Over and over, again and again I bored into this tree. Maybe twenty times. I used the bottom of the nose and the top of the nose. Not once did the saw kick back. They just stood there amazed. Even the owner of the company couldn't believe it.  I'm not saying this to brag or anything, just that once you learn this skill it will seem a natural thing to do.

Now there's one more little detail that I haven't told you yet. When I bore my back cut, with the saw held horizontally, I'm not going straight in with the bar held parallel to the radius of the tree. I have the saw rotated to the right about 45 degrees or so, I start my bore cut, and then I rotate the saw to the left, clockwise, and then push it into the tree, all in one motion. The angle I hold the saw to the tree to start my cut varies with the tree.

[John Mc]

I think I get what you are describing. When you say "rotated to the right about 45 degrees" you are rotating it toward the top of the nose. I can see how this could help pull your saw into the cut. That's basically what the initial part of a kickback is doing, although more violently and uncontrolled - it pulls the saw harder into the cut. In a kickback, the tooth grabs so hard, it throws the bar out of the cut.

What was confusing me was that I thought you were saying the top of the nose helps pull you through the entire bore cut... which just doesn't make sense to me. I think what you are saying is that it helps you initiate the bore cut.

Neat trick. However, I think I'll stick with initiating it with the bottom of the nose. If my chain grind is just a little off (rakers too low, as I seem to be experiencing now, for example), I'd be more prone to kickback using the top of the bar. Apparently, my sharpening is not consistent enough to count on at this point.

John

[Frickman]

John Mc,

You get the idea of what I do. That's good. It's not for an untrained operator, that's for sure. Like I said before, I've been cutting professionally for decades. I sure didn't start out when I was a youngster bore cutting. It took some time and alot of practice to get onto it. One thing that I learned early on that you're learning now is that you have to have your chain sharpened correctly and a bar in good shape. If you don't bore cutting gets kind of difficult.

I have a rotation set up for my bars and chains. When they're new they go to the woods to fell, limb, and buck timber. As they get some wear on them they're used to trim and buck on the landing and at the mill. At the end of their life cycle I cut up firewood at the mill and trim the occasional dirty log. I do this because I need the greatest amount of accuracy at the stump. As the log travels from the stump to the mill the need for extreme performance of the saw decreases while the accumulated dirt on the log increases, dulling the saw and further hurting performance. When the bars and chains make it to the firewood pile they're pretty well used up and sometimes not cutting all that straight, but it doesn't matter as it's only firewood.

[aldo]

I can't help with the chattering except to say I have a little Husky 142 that I use with a 16 inch Husky bar which has a small radius tip and for some reason it chatters on bore cuts too. I have no idea why but the problem is lessened when I use a new chain, still there but less. My hand filing has never given me any problems before or on any other saw I have. All the other bar tips though are larger radius.

As for bore cuts, I often start with the upper edge of the bar. I just exaggerate the angle initially to pretty much eliminate the chance of kickback. As I create a deep enough pocket I begin to straighten up the saw. Usually it's difficult access, another tree or limb or fence etc in that way. I have never had an issue though. As for doing it for every tree, mainly for heavy leaners or trunk bigger than the bar length.

[Tom]

Hey Aldo, wecome to the forum.

I usually start a bore cut on the bottom edge of the tip and roll the tip into cut such that I'm pushing straight in.  I can't think of anything that would cause chatter but a loose chain, or maybe a dull chain.  I do apply a positive pressure when bore cutting and it seems to go pretty smooth.

Most of my bore cutting is when bucking logs.  Logs laying on the ground that are supported on the ends, will pinch a bar.  I bore cut about a quarter of the way from the top and then cut to the ground.  The "tie" at the top holds the log together and allows the kerf to open rather than pinch.  I then come back and snip the "tie".  That's when the bar might get pinched a bit, but experience will show how thick the tie should be.  If thick enough, the top of the kerf will close and hold the rest of the kerf open, until you meet your original, bored, kerf.

[joe_indi]

Try replacing the rim sprocket, if the saw is running one.
If it has a spur sprocket, have grooves cut deeply into the spur?
If the grooves are deep, this could be the culprit.
A worn nose sprocket  might also be the cause.

Joe

[GASoline71]

S'cuse my being naive... but I really see no sense in bore cutting every tree when fallin'.  Especially trees that are only 10"...

I have been doing this many years... and have some big trees (30" plus over 150' tall) notched in my belt...

I am in no way an expert... but if you have to bore cut every single tree to keep from a "barberchair", then the fallin' technique you are usin' (non bore cuttin') needs to be addressed...  Whether it's just me... I don't know.  Because my intent is to not "call out" or make anybody here feel inferior... but 90% of the people I have come across that use a bore cut to fall every single tree... are making up for lack of proper technique in plain ol' tree fallin'.

That being said... it should be the other way around.  You should be fluent in good/proper fallin' techniques before usin' stuff like bore cuts, "dutchmen" cuts, Coos Bay cuts, and the like...

All in all... be careful... if you contuinue to use bore cuts for every tree... that's your business.  Just don't rely on it to save your butt as the "safe way".  Because it is not.

 

Gary

[Rocky_J]

Gary, take your common sense and get outta here! 

[Al_Smith]

I suppose it's just a different method of doing things . I might have bored half a dozen trees in my lifetime  and they were heavy leaners .

Oh you hear of some who expound on it but usually they are cutting for grade or figure.  Which means very little to 90 percent of us, if we get a little fiber pull on the end of a log ,we just cut it off any way . Much ado over 6 inchs of wood IMO .

[beenthere]

Depends on the tree.

Knowing the technique seems a big benefit, and knowing which trees need the possible extra control one might get from bore cutting, also seems smart (er) in the mix of things. 

I've started bucking a lot of logs for firewood with the method Tom mentioned. Saves sticking a wedge in the cut to keep from pinching the bar.

The speed that some people can cut is another factor. The young guys that move around fast, have plenty of time to steer the tree as it falls. The slower guys like me enjoy the extra time to set the wedges after the bore cut, and nip with a backcut to make it fall.

Almost like everyone can be right. 

[mrcaptainbob]

Between the felling notch and the bore cut, there can't be much left for a strap, considering the width of top-of-chain to bottom-of-chain.

[ErikC]

  I bore a heavy leaner once in a while, but seldom any other time. Bucking logs in the PNW is often done similar to what Tom mentioned, but I think it's a little better way. I start at the top, cut in a few inches, pull back most of the way and drop the bar a couple inches without removing it, bore in, cut out the bottom all the way, then the last piece from the bottom up. Never take the saw out of the log. The log doesn't pinch, and its as fast as it could be. I get a little chatter when boring in once in a while, but usually a little more pressure stops it.

[Maineloggerkid]

I bore-cut trees that need a wedge. It allows me to set the wedge without worry of the tree setting back. If I know its gonna go where I want it, or i can swing it where I want it, I don't bore-cut it. I do find the technique in-valuable though.

I was taught to bore cut with either side of my bar. In some cases I actually prefer boring with the top of my bar. More risky, but it seems to have its place.