Dent on Hinging

[TheTreeSpyder]

This is the type of model you might see in D. Douglas Dent's "Proffessional Timber Falling-a Procedural Approach".

Such mechanical, straight forward diagrams to repeatedly poor over, have helped me get a real feel for all this.

If it takes removing so much fiber across face to fold, it doesn't have to be even, it can be eliminated in such a fashion, as to leave diffrent combinations of fibre for diffrent applications.

The outside corners of the hinge, give the most leveraged pull to the opposite face, eliminating some of the fibres, under the side of off balance pull , or head lean to one side of hinge, leaving more fiber pulling with greater leverage from the opposite side . You would always fold into the face of the hinge, this manipulation of the positioning of the final fibre on folding is to even off balance of pull across the axis of the length of the hinge.

It is kinda like, if u cut the guy wire on a tent, it falls the opposite direction, it releases it to go that way, so as it is here too. So if head weight pulls to left, it isn't going to fall to the right against that weight of pull. So eliminating the fibre that keeps it from going right is ok, cuz it can't, seeing as the fibre that controls right hand drift is on the left (under the off balance head weight), it is okay to eliminate this fibre. Then that amount of fibre isn't lost, the log will folde at same amount of fibers holding, those fibres are now scheduled to be on the opposite side of hinge, the cross axis to head weight.

Exactly at the highest leveraged position to fight the off balance head lean on the opposite side or cross axis.

 

[TheTreeSpyder]

So then applied like this. So that, the greater fiber pulling right, balances out the headweight pulling left; therby delivering in balance point of forward vortex (gunning angles) fo hinge face evenly.

That hinge can Fall, Holde or inbetwixt those Fholde.

So you always eliminate fiber to fold to that gunned point, and use leveraged positioning of remaining holding wood at tear off to balance out any side to side pull by gravity on that angle.


The openness of the faces determines the amount of fholding sweep that is maximum, for when the 2 faces meet, the hinge machine must sieze or tearoff. So even this is a mechanical instruction.

So not crossing the face cuts is very important, for the inner most hinge will be the lead mechanical instruction and will close very early, because it is a narrow facecut.

 

[TheTreeSpyder]

In bucking the forces to be released are similar. Even practicing it you are releasing forces in wood fibre to your specification, you can learn alot about all other cuts, even here as you observe what you are doing and its effects with these guides.

 

[TheTreeSpyder]

So then i brought Dent's models into the tree, turned it sideways, like this.

Now, you still gun focal of hinge to best place, run a wide face for wide sweep, and schedule final holding fibre at tear off of the hinge, directly levearged against the offside pull of the hinge's axis (here it will always be pulling down, not to side, less confusing while learning!). It is all exactly the same but difrfent, the same principles in diffent clothes and arraingement. As i practice any one of felling, limbing or hinged rigs i learn about all as a category, not seperate events.

So, if you are trying to throw a horizontal limb sideways, the holding fibre will be at top of hinge, directly confronting gravity from pulling directly down as hinge ushers sideways. Sending it to 9:00 will probably make the hinge shear, as the machine fails to meet the request as it is asked for too much. But, sometimes sweeping to 7:00-8:30 is sufficient, an open path. Maybe to just hand it off to rig, or pivot on its own. That weight at the end and the length of branch become a useful mass and leverage for closing the hinge, thereby moving the head around.

In a torqued, 'flipping' rig, i've mentioned before, -i don't- eliminate the bottom of the hinge. For in that case, the limb wants to flip, the fiber at the bottom of the hinge is in most leveraged postion to keep it from flipping, so it is this lock betwixt the 2 forces that lock and cause it to torque around. Of course sometimes that flip will get it off the roof (that slopes and becomes more forgiving anyway), especially if the top is clear (it will face the roof on flipping) and the bottom is the problem (that in flipping will rotate up out of the way), then i will walk the fholding hinge cut down to a small bundle of fibre at top of hinge on a tight line; allowing (by taking bottom hinge fibre out, that has most leverage against flip)and commanding (by line placemeant), as the machine commands if that is good.

Sometimes,starting with a tight line and make it self tighten more as it sinks, so that it acts as a tight steel arm, that will not let the limb down any more, but commands that it arc around and not sink. If this is compatible to arcs of force desired by gravity and hinge, you can usher many things by compounding there values.


i think this stuff isn't understood enuff to be used and observed powerfully, it fascinates me, sometimes heard it laugh as it eluded me. i've tried to expalin it b4, hope thes pix help, and i think Dent's book should be required reading, i keep going back to mine! Dent in "Professional Timber Falling" opened my eyes to what was going on around me all the time, and empowered me by naming the basest components of their structure for me to recognize in various forms, determine what stood against me and how to minimize it, and what stood on my side, and how to maximize it to apply overwhelming force to positively control a motion.




"Fascinating Captain!"



P.S.- i guess i will load that pic when circimstances allow, Hope this evolution of thought makes some of this clearer, and whets your appetite to witness these things.

JP's off on another secret govt. mission, ooooooooops

 

[TheTreeSpyder]

Let's try again..........

 

[TheTreeSpyder]

Here is one of a more actual model for field, taking all this 1 step further.

Same deal, 2 dimensions of space to consider, 1st the dimension that folds on the hinge and it's axis (axis would be N to S on a E to W long rib of hinging wood fibre across the face). So it folds directly on the flap of wood, that is it's axis. So you don't run in front or back of a hinge, though the back has some safety, with the kerf cut closing and siezing (hopefully) if tree goes backwards. So of the 2 directions on the axis, that makes the face the path of lest resistance. But directly back is in the kill too zone because it is on the axis that the hinge (the machine here) will deliver the load to(N to S).

Then the 2nd dimension is the cross axis or 90 deg. to the hinge's axis. (cross axis is E & W on E to W 2" row of hinge fibre. Weight pulling across the axis of the hinge (on the hinge's cross axis, E and W pulls in headweight) are thereby supported on the cross axis by the hinge material in the opposing corner of the pull.

So a W off balance headweight is pulled E by rope to balance pull to fold forward to N in balanced fashion. The line pull hopefully balances the head pull, by contacting at the appropriate leverage point per pull applied, to balance the offside lean of weight/leverage. Or you can have excessive fiber in hinge on E side too or in tandem with line pull. It's the same thing, pulling across the axis to balance the other side by the fibre of rope, or the fibre of wood.

Now, if it might brush something on the E on the way down, but you want the fall to stay a steady course, you would put holding fibre in E corner of hinge, to keep tree from being pushed W (fighting same effect as it being pulled W, with same strategy of fibre in E side of hinge, in most leveraged position on face to fight such a force to the opposite direction). In this way, the increased fibre would hold the tree to the E, as it brushed by the tree on E, laying it where you want it, instead of allowing the path to be pushed W.

Notice how the green in "Pre-final Cutting" extends outside of neat pie slice, how fibre to werking corner is maximized at fholde, while still maintaining a stable 'base'.

 

[Kneejerk Bombas]

Just for the record, I disagree with almost every concept discribed here.

 

[DDM]

 

[rbtree]

great work, ken..

I think it is time for you and me to find some woods and play with some swing and step dutchmans!!!

At the Clearwater Revival, I showed up one day late, but still came second in the felling contest. Missed the target by 11 inches. The tree (a 40 foot stick stuck in the ground), had a bend at the top that was a good 7 inches, and i didnt compensate for that enuf-or move the beer can closer in, dang!! Plus I held a bit too much wood on that side.

Then, I got to run Dennis's racing chain on my Greffardized 3120, which is modified for work. i ran against the Rupley brothers with their full race saws in the "stock" appearing class. I was ony 15% slower, not bad for a first timer..It also was the first 3120 Dennis had built. Later, they let me run their piped 090, wow what a saw. Maybe 1.5 seconds in a 17 inch log, oh yeah..And watched the Predator pull a 1.2 second cut in a 30 inch log...!! 440 lb, over 300 hp, kind of heavy for trim jobs huh?!

Do a search for "Dennis". He builds "Greffardized" saws, top class work, for ~$200. I now have three. My 346XP-G is flat out unreal, it makes that 026 seem like a dog...which it is, actually....

 

[TheTreeSpyder]

Thanx RB,

Mr. Mike- i've come up with some assembled observations before that we seemed always to play point-counterpoint on, in an open field. Things of reflections on understanding forces or whatever that in my experience seemed to hold true as i named them, but seemed to make no sense to others. But, these things are written down by a 'master' previously to me, and it has taken me years to absorb their simpicity. So, i must even more so stand my ground here, perhaps you should find the book, might be the best <$20 ya spend this year! And i beleive that goes for anyone that is serious about cutting!

i've tried to refer to these princi-pals in diffrent weighs across 3 boards for a few now, kinda felt good to assemble and organize them all at once in my head. Especially carrying it all into the tree. Also perhaps to give a common base for understanding, and now have it printed teaching someone else from it, as i bounced it of y'all. Actually there questions propelled me on through some of it. i beleive these principals are true, mechanically correct defining models. Breaking down a series of commanding properties, into their smallest 'prime'(numberic refrence) and modular pieces to assemble. To make a machine that gives mechanical instructions to a tree falling, and not haphazardly. To know when a cut is a lil sloppy by these standards, and will make it anyway and -Why; and when it won't and Why.

Kinda steered from the dutchmans here, a lil more dangerous to reccomend (to say the least). By "mechanical analysis" (a super 'Dent' term that changed my whole outlook on cutting) i think basically the dutchmans work by the slamming forces in faces meeting an obstruction on 1 side of the hinge at close. So to me that calls for/assumes fast slamming action, without widemouth faces. i have been working these princi-pals to the other side of that. Besides, wouldn't be fair to give a way the whole book; its quite a work!

 

[Kneejerk Bombas]

Ken, RB(I ask you because you agree with ken), and others,
look at my drawing and answer which you think is stronger in each of the six examples:

 

[rbtree]

And your point is....?

Advanced felling techniques are performed for reasons, to overcome problems. Of course, a normal shaped hinge will be stronger in all of those scenarios, and can work if other procedures are performed, such as wedging and side pulling.

The use of hinge wood in triangle shape works well with head leaners, as option to plunge cutting. I like it because the tree doesn't fall all at once. Plunging is probably safer. I do both.

And the use of holding wood works well in most situations, if you understand the tree's fiber characteristics, degree of lean, etc.

I use both of the above quite often, moreso when working aloft and with branch wood.

 

[rbtree]

Ken,

I agree re Dutchman's. I've never tried them. I believe their use is considered "illegal" in forestry applications. But I'll sure try sometime if I have the appropriate tree(s).

Mike,

You also should read Beranek's book. I guarantee you will learn a few things, as you will from Dent.

These two learned fellows dont talk much about the open face, or using plunge cuts to set up the hinge. I think both are good to know and apply, but not all the time as some are teaching, including Ard and Arbormaster. Especially with tall straight conifers or straight limbed sticks with nice clear grain. For instance, my tech. of using a deep, very closed face to control spin rate on long logs dropped from a height. Ken Palmer, who has never had the reason to do this, thinks I'll get bit someday using this method. not me. You have to be flexible, and I found Arbormaster training to be somewhat lacking in that area.

 

[TheTreeSpyder]

Mike, your pics are usually so good, but that one didn't download for me quite to a viewable point......

The more you depend on holding wood, the stronger, more flexible it must be, this wiil be species, lively, temp dependant as the machine of the hinge becomes more dependant on this item. Conversely, it also shows if you have a natural defect (deadwood spot etc.) how its effect can be evaluated in your hinge as you inspect the facecut previous to the finishing backcut.

i think in RB's example of reducing spin, that his coming back further undermines the vertical center of balance more than a shal-low cut, preloading it more for ejection. Then, the nar-row knotch gives the instruction to shear early, i imagine ya kinda race that closed like i was talking about b4, maybe coming off in time for the 1:30 train.

i know we aren't always going to agree, we all have proven that! i just kinda feel less room for argument here, sometimes i state my case, and back off beleiving the same thing still. i could be as wrong as Mike !!!!!! Know, really; um, this time i must say, i have more backing and experience than that of some of the other topics i might have backed of on; and raise my hand and step to the front and say so!

My elm example was on the extreme, but addressed a topic i have been hitting on using that example, showing the possibil-i-tease that i might be the first to see. In actual practice, i may have peeled over some limbs with a sidewards/down cut, but leaving them hanging towards the house. Thereby reducing the leveraged pull on its connection, reducing its length and bringing it closer to the ground. If i got the 2 legs towards the house to hang and it was open away from the house (no hanging legs) i would nickel and dimme unnecessary weight out. Then i might have tried to ease that branch over and down, allowing the 2 legs to hit the ground first (on house side) , letting that push the rest of the limb away from the house then cut it free. then i would have a nice matt for dropping stuff. Now without standing there, can't tell, but not all my stuff goes to super rigging, but; i never try to escape from awareness to the whys by not thinking about gravity, leverage, flow, elasticity etc. It has taken a while to break things down into modular, logical, smallest pieces with specific properties to be assembled or reckoned with, even longer to be orderly enough to present it!

i really beleive these are mechanically clean models, invite any open conversation on this topic, that is why i posted,as well as collecting and sharing my thoughts, here and at home. i also beleive safety topics aside, this is about the most pervasive, important and least faced of non-biological topics of tree work. The hinge is a basic component of all these things, that should be understood specifically to really understand the whole picture.

i agree with RB, i use most of this in the tree, i do more climbing then felling anyway. But, the book is about felling, it is safer and more prevalent to learn these princi-pals that way. But they are principals to be faced in all phases, not a seperate topic that can't be carried into the tree.

 

[rbtree]

Ken,

roll your mouse around on the lower right quadrant of the pic, you will bring up an icon, clicking on it will enlarge the pic to a very readable state.....

goota go remove a fallen cherry from two yards, by myself as the crew is hurt, then do a mess of bids..

..the saw junkie

 

[TheTreeSpyder]

okay Thanx RB....... Nice job MM....


A-2?

Any would fail/fold easier with a hinge/kerf cut to the face of the pull. If A-2 was pulled north, and only cut on west side, it would fail at the east/strongest corner last, unless there was another pull pulling NW that balanced the stronger fibre pull to E. Same specifically imagine-able in B2, D2

To me this all is a gravity powered machine, the head is the power input, the facecut a chock allowing 'roll forward' if removed, the backcut allows gravity to power the machine, the power of gravity pulling on the head goes through the length of the log to leverage that head's Maas on the hinge IMHO.

Soooooooo, if there is 1 ton of headweight, 40' up from the backcut, that is 40Tons of pressure pulling on the backcut/hinge + momentum+leveraged weight of 40' spar. So, if that comes out to a measley 50 Tons in this med./small tree, and 20% of the head weight is off to the left, that is 10tons of force off balance that is real force, that must be reckoned with for a high rate of success, i think.

Any weigh, finding the secrets and basic principles here and being so fluent as to site them out and command them in all examples can truly benefirt all here i think.

 

[murphy4trees]

It seems logical that a spar's spring is caused by force on the hinge, which is the only thing holding the foward momentum of the top to the spar. Accepting that, less force on the hinge would load the spring less. An extreme example would be after the face closes, all the force required to break the hinge loads the spring.
So it makes sense that an the size of the notch, open faced vs narrow would only matter if the notch closed before all the fiber in the hinge was broken, although maybe there is somrthing in the model I have yet to see.
So wouldn't it be better to use an open face notch? Maybe it's not neccessary if indeed you can cut all the fibre around 1 o'clock, but what is the advantage of a tight notch here?
As far as using a standard vs. humboldt, I prefer the humboldt if there is any chance of the top hanging up. Otherwise there may be a slight "slide off and down" advantage to the humbold, yet again the size and configuration of the notch seems to me to have less to do with the spring effect than the force needed to break the holding wood.
And again THANK YOU SPIDY

 

[rbtree]

Hi Rob

The only reason for a closed face is to allow the log to pop out, thus slowing the spin rate. I usually use this for dropping 26-36 foot logs from 30-45 feet up. I want them to land nosed in at 10-30 degrees off flat. More is not good, as the log could flip over. Less is better, as it digs in less, doing less damage. Flat is not possible with most of the above combinations of length and height.

By the way, landing flat can break a log, especially if it is falling from way up there or is rather spindly.

Since your ZingIt was not put on a tramp steamer, it should be gettin there purty soon!!! Unless it was on a DC-3 with a feathered engine.....

 

[Kneejerk Bombas]

This topic is too much to handle all at once.
I suggest we look at making felling cuts, a piece at a time.
We all know notches have different angles of openness, from a kerf cut to an open face. The back cut can be straight in or all goofy, as spider showed. Some think the backcut should be plunge cut and made with a little holding wood at the back side, only to be released when one is ready to fell the tree. What drives the felling cuts though, is the hinge.
I am suggesting we talk about the hinge first. I'm suggesting we talk about the hinge, and only the hinge.

I say the best and strongest shape for a hinge is a rectangle, a wide thin rectangle. I am here to defend the position that a rectangular hinge is the strongest, and therefore the best hinge you can make. How about a round hinge? No, a rectangle is stronger, in every instance. A triangle? No. A Mickey Mouse with ears shaped hinge? No, a rectangle is stronger.

Let's not muddy the waters with talk about wind, dull saws, how much Forrest should charge to prune a tree, just talk about the best shape of a hinge.

 

[Kevin]

Too many variables Mike, it`s like asking what`s the best way to drive a car?
What you describe is a basic hinge under perfect conditions.