Center of Gravity pivotal concept

TheTreeSpyder

Well-Known Member
#1
We's kicked this around elsewhere's; and to me, important enough to infect here also...
WARNING: long conceptual post ahead; challenging some popular concept's imagery
>>some would advise de-tour now ;brain in tact; instead of change everything!
.
Simplest CoG(Center of Gravity) expression: uniform log, balance horizontally @ CoG on vertical post ;
can view post as a needle exactly aligned to this center and so balances in this singular, unique point;
>>realize will fall in direction of CoG if post not lined up to CoG collective forcepoint.
Alternatively/just the same can take view that post simply divides log into 2 halves
>>each half exact ballast of the other at the CoG so log doesn't fall
Either way, the relationship between the CoG and support is ruling concept
>>the form/shape of log itself just offers positions to communicate to the CoG thru!!!
>>in electrical schematic sense, the CoG is the source/src active + voltage
while tree/rope is as weightless wire conduit (only here geometric angle counts) for the +CoG forceflow to the support's passive ground sink/snk!!

child's play :float pencil horizontal between both forefingers wide.
>>move fingers slowly inwards; 1 side slips, other grips as CoG between fingers adjusts to bear more friction on heavier side for pencil to grip that finger more and slide to re-balance until fingers are in center at CoG
child's play: grip pencil at CoG horizontally and shake up and down, looks normal
>>grip offset from CoG horizontally and shake and pencil seems to bend as motion is defined in pencil from CoG, not fingers!!!!
>>longer dowel, effect exaggerated; more distance input from defining CoG; imagine 'bending' 'proves' dowel weightless form of leveraged positions to confront CoG from....
>>eye sees, but can't define anomaly to brain, so we see the impossible pencil bend!
.
Concept: CoG doesn't have to be on a physical part of the device...
>>the CoG of a metal donut, is the center of the metal donut; in the hole itself!!
Here can see more clearly, CoG not on physical structure, but move structure/donut to alter CoG defining forcepoint position.
We define the CoG in the shape; REALLY should define the CoG position as point in space/time and then define the orientation of the weightless shape around the CoG!!
.
Center of Gravity (CoG) is such an unrecognized, invisible ruling concept of all motion and non-motion (secured) as well.
>>Trees growing larger/heavier than anything else; just express the concept more; revealing this life concept to treemens more than normal earth walkers!
.
In felling, rigging, growth etc. CoG is the sum total of all the weight and leverages of a device; expressed in 1 point.
i look at a tree, log etc. as absolutely a weightless form; with a single weight ball inside : the CoG
The position and angle of the CoG (within the weightless form) in relation to support;
ABSOLUTELY defines the leveraged angle and loading, where knots are tied, what direction knots are tied, how the device moves, impacts etc.
.
The angle of side lean from CoG to hinge makes the loading pattern in the hinge
>>this defines what areas of fibers are compressed;and what areas are stretched
>>maintain position of all and increase weight of CoG and keeps same pattern of loading in hinge; just more intense within that pattern
>>likewise, keep CoG same weight and angle(so mathematically same sine and cosine in this equation), but just change height(leveraged distance of CoG from pivot) and we have the same pattern of loading in hinge fibers, just different intensity of loading within that pattern.
.
If you stand in a light rowboat, it is much less stable
>>you have raised the CoG / making boat more tippable
>>BUT base of boat width is same resistance to tipping as when CoG was low
>>base width is anti-tip leverage, CoG is wanna-tip leverage
>>standing in boat makes wanna-tip leverage greater than anti-tip leverage
larger, heavier boat effect not as radical/or not seen; when your bodywieght CoG leverage is inconsequential to the weight/width of boat that then keeps CoG leverage low in relation to width/weight of boat.
.
In martial arts fighters squat to wider base AND lower CoG at same time for MUCH more stable formation
>>like pyramid; low balance;wide base is most stable.
>>upside down pyramid shows exact opposite in pruf;much less stable hi CoG,minimal base
.
Gymnastics hi-beam is meant as an expression of femininity:
The 4" wide beam is mechanically MUCH easier for the lower CoG and wider hipset of the female form!!
.
Soooooooo then a man more likely to fall out of back of pickup truck bed
>>CoG would be force to keep in truck
>>side of truck edge as forcepoint is keep-in-truck force line
>> would want to sit low; keep CoG lower than edge of truck
>>wimmen's is Naturally lower CoG
>>when taking boys to games etc. (long ago now) would teach/preach this is why to stay low in truck bed; keep man CoG (approx. solar plexus in male vs. almost hipset in wimmens in standard/leaner builds)
Large low gut can give lower CoG, but be harder on back cuz harsher angle from pillar of spine
>>it is ALL geometric architectural ; once't TomD quoted someone else (sorry fergit) that trees should considered as Bio-Mechanical devices
This rang true immediately and reverberated deeply thru for sometime until could hear in all the nuanceses even as the bell's tone faded: all life is subject being this bio-mechanical consideration; trees just exemplify this so we can see easier, cuz they are so big in ALL extremes!!
.
If take low weight off tree, can decrease total weight, but wait, lower weight was pulling CoG lower for more stable form! So could have worsened stability, tho decreased intensity of loading in that higher risk pattern.
>>BUT on some days this still gives GREATER leveraged load sum total from formulae of height of CoG from support pivot (as potential leveraged load) X sine of angle of same CoG to support pivot as a 'percentage' of the total potential leverage(cosine of angle would give inline loading 'percentage' of the inline/nominal/un-leveraged weight potential)
These lower wight changes can then affect height AND angle of CoG.
Compressed Pivot part of hinge carries the inline part of the load/tree
>>PLUS the leveraged part of the load
>>PLUS the resistance to the leveraged part of load/tree (from stretched fibers in hinge)across
note:compressed part of hinge is the most loaded, so is pivot
note:in my imagery force will run like electric force flow from CoG as source; trying for most efficient/laziest straight line path to defining pivot,and the straight as possible line to tensioned hold fibers
note: if hinge (or rope..) fibers slide thru a 'gradient of loading' from compressed to tensioned fields
>>then logically there is a most neutral field betwixt that is neither stretched in tension, nor compressed!
.
i think if rope meets log at CoG is only time/unique event that it is mechanically correct to only have running Bowline, Clove etc. holding.
>>ANY other time should have a Half-Hitch(HH) or Marl proceeding the anchoring runing Bowline or Clove etc.
>>further more the HH definitevely (and preferably the anchoring knot) are before the CoG position or HH can pull open; CoG again the ruling force.
Standing Part support is like fence post; needle should line up w/CoG or is mechanically wrong
>>more properly the Standing Part support, should line up with the CoG and then the securing other side of rope eye in straight line
If running Bowline to log load is not at CoG; the resistance hold securing eye will be at stressed angle/NOT INLINE
>>see how HH corrects this and places it's main resistance INLINE to Standing Part as support
>>see how HH is simply a modifier of the force flow that is now correct

Note how especially in #B the securing rope stop opposite Standing Part is also best Nip
>>because of consistency of these principles!
.
This is how much (and then sum) CoG means to me in all aspects of life'smechanix all around us let alone expressed so visibly in all that we do! Every tree, every rig, every step we take, every fall we make!
.
Have tried to show if connected, the relationship between supporting connection and CoG is the TOTAL ruling concept.
>>But even when free agent/log falling/no supporting connection the CoG rules!
If hit enough force at CoG would push free float log inline back/up whatever equal/opposite direction
>>but if hit free agent log below CoG can log can spin rotation down, if hit above CoG opposite spin
If CoG not connected to support pivot; CoG itself becomes the most loaded point, thereby the pivot!
Weightless shape just carries around the CoG forcepoint as it's pivot!
Weightless shape is just handles to talk to the CoG forcepoint thru and CoG to comm(unicate) it's forces back thru!
.
CoG rules!!
orrrrrrrrrrr these would fall like eye says should!!!:

EVERYTHING else is the same!
Tree work just so much mor1e intensely due to the scale of weight/length/rigidity that these same ruling props are expressed by!
As treemen we get this gift view of life concepts as few other see; so large on our stage,we must be in front row to see what many others miss as part of our bounty!
.
i truly believe, if'n you can see a rig or a tree felling as weightless forms with CoG's to pivot schematic in head; it is easier and more intuitive to innately make the right mechanically correct moves!
Grooming each laced knot like a craftsman making an architecture to these most raw and correct defining concepts.
.
orrrrrr something like that!
(sorry so long,but BIG concept, BIG implications all the way thru safety handling / predictability etc.!)
 
Last edited:

TheTreeSpyder

Well-Known Member
#3
Thanx, actually, have done much searching for my own self to get here!
>>i try to feel these forces inside, as checksum and to make more intuitive.
.
To me, tree is still empty, weightless, rigid shape
whose forces are just a see-saw fight of active load vs. passive hold;
thru the leverages to the common,shared central pivot in between force wise (even if not physically);
that takes on both their loads; like a pulley as central pivot taking on
>>both the tensions of incoming and outgoing parts of line to pulley.
+ inline forces directly over this pivot!

The shape offers load and support forcepoint positions that are within it's domain;
but then we must plot the forcepoint positions to find how the forces race thru the system;
as satiating equal/opposites; and everything is balanced/ not moving;
if there is imbalance the load moves to the new balanced position (mo'fo not satiated, leaves!);
the motion itself making up the imbalance in the formulae for the time being!
Everything is in balance, because if not / it changes until it is; the changes themselves make up the imbalance!
So everything is really in balance!
>>this also gives handy checksum to formulaes!
Totally leveraged tree:

.
partially leveraged tree:
CoG is the initiating forcepoint
pivot is most loaded forcepoint
>>Nature is lazySmart and takes 1st avail. support (if any) as most loaded pivot forcepoint
(IF/when no support/free-fall; CoG is the most loaded point; and thus becomes pivot.)
 
Last edited:

TheTreeSpyder

Well-Known Member
#4
TAPERED HINGE LOGIC
In my own internal imagery of tree shape as a weightless, rigid container in which exists CoG weight ball that gives the shape weight force;
just as battery empowers wiring.
>> i think of the narrow path across hinge as how i urge the empty,weightless shape concept to fold
>> while longer axis of hinge/with more leverage against force; is used to control the CoG actual force in the shape
Face where you want the tree to fold to; but control any offset weight distribution by shape of the length across hinge, to Tapered Hinge concept.
Essentially use an offset support, for an offset loading!
.

.
If you are a handyman etc. that always just fells into the lean; this concept doesn't apply; can use'generic' straight, simple hinge(because CoG in unique position that lines up to fall)
>>or if always have straight pure inline pine pole that routinely give false forward lean with rope or wedge
BUT, for those that an 'easy lay down' is not the standard, but rather a unique instance;where the standards are:
>>getting a limb to move sideways when pulls down as the same mechanix as
>>getting a tree to fall beside the lean force not into
Tapered Hinge gives the offset control, to the offset lean, properly
>>while a generic straight hinge, cuts the most leveraged, necessary fiber positions, from what tree is using most!!!
Another reason i think to not fell into lean when can; softer hit(and practice)!
>>felling directly into force of CoG would be into most fierce pull of the force
>>using tree to fight itself and consume some of the CoG force,and not feeding directly into strongest pull; logically less than full force fell to me.
.
The backcut should reduce the leveraged restriction to the shape's PATH FLOW
>>BUT while maintaining support leverage across length to control the CoG FORCE FLOW to that same path!!
>>Don't let the CoG force shear the shape it control from given path to target
So, we look to control the empty weightless shape with 1 leveraged aspect of hinge and the force with another leveraged aspect of hinge.
.
i wouldn't use a generic/simple strip hinge for a really side loaded tree/limb scenario;
anymore than would use Tapered Hinge for an easy lay forward into the CoG w/o sidelean!
Simply the wrong mechanic to the pre-existing force flow pattern saw cuts into!
 
Last edited:

rope-a-dope

Well-Known Member
#5
Epic thesis.
Trees become such awsome gravity masters when the balance of energies is considered. The values of tension and compression are completely equal, perfectly matched to maintain stillness. Then the wind blows and it dances!
The sawyer's art is to remove just enough of either to imbalance the center of mass and produce exactly the required motion.
The view presented here of mass and space and energy is very much a door of perception. Everything is breathing!
I agree, Spyder would be really fun to talk with.
 

TheTreeSpyder

Well-Known Member
#6
So, simply for a load that the CoG weight is offset from the path to target;
>>we just offset the pull of the tension fiber positions to fit where Nature already has these pressure patterns.
Many hinge patterns will give the same fold forward resistance to the scenario
>>we pick one that simply also fits the load imbalance across, with a responding imbalance across hinge to fold balanced to target.
Flash is going away, but for those that can still play; i offer this from years ago:
http://mytreelessons.com/rl/content/Hinging-Full.swf
plan to make youTube with it at some point
.
COMPRESSION LOGIC: DANGEROUS DUTCHMANS
Compression is more DANGEROUS to play with, as the tree is more confronting it's own mounting forces to control,rather than the tension side where you are pulling away from the control/eventual tearoff as releif; compression is mo'in'yo'face!.
.
Just as tensions can be imbalanced against a load from rear, compression/face close imbalance can offer similar in front per the red/blue active patterns in response to the CoG!
BUT, can be so powerful, more unpredictable; the lesson here mostly is how it functions, and why NOT to do it!
To show logically how much force pattern, impact of change and why to machine front face perfectly so as to not accidentally invoke/call-up these forces!
.
Dutchman blocks path from raging forward forces of tree felling to redirect,can be kinda like brushing a tree that throws the fall off, only the Dutchman is in the mechanics of the face itself, not in the field of the fall.
.
The most oft made Dutchman; is the accidental, full face kerf one where the typical bottomcut that is perpendicular to the grain/fiber bypasses the other/upper face cut.
This smaller kerf face within over rules the main face and closes very fast and sudden, AND offers no path of relief as the internal forces keep raging forward into the deadstop full across path. This can give a 'split decision' of a Barber Chair where the war of internal forces over rules the constitution of the tree container; possibly splintering parts of it!


More properly we would only Dutch block the sidelean side; offer the offside as the open path;
that Tapered Hinge is pulling also to in harmony.
We'd do this by kerf to that sideLean CoG side only, wood block in that face OR dropping the other offside face lower.
Whatever gives us face compression imbalance, as Tapered Hinge gives tension imbalance!
.
BUT, can be much more unpredictable especially at tree felling load ranges; especially multiplying more with faster/stronger fold for more face slam and then so the response...
Once again, realizing power,backing away, making sure don't accidentally invoke; this is just a discussion...
BUT, in lower loading ranges of climbing and bucking; i have found plenty of safer utility in the practice.
i still speak in standard felling scenario to show power, brutality and why not to do..
.
Tension control is given,but rips free; compression control keeps confronting itself!
Compression is push in face, start by closing sideLean side earlier, to push earlieras offside doesn't push.
BUT, we can have a change in mechanix; when the Dutch close on sideLean side becomes so intense;
>>and loads higher than the hinge compression; i say the pivot of the worx changes to the more loaded Dutch point
>>This gives HIGH impact of change suddenly in system, because changing central pivot changes CoG load leverage to less,and gives more leverage to Tapered Hinge support at same time!!
ALSO, earlier tear off on sideLean is possible, allowing powerful swing to offside
>>becuase part of mechanix of compression side of hinge in these scenarios is 'anti-swing' to stabilize against over correct!!!
Suddenly less leveraged side load and more leveraged support thru whole system!
CAN BE VERY DANGEROUS SUDDEN UNPREDICTABLE CHANGE
>>IN REAL TIME >> WITH REAL LIVES !!
i say again, my friend: "Nature, to be commanded, must be obeyed" -Sir Francis Bacon
.
In using some in climbing for help sweep limb across, or bucking top compression:
i simply go with Dutch concept on the vertical gravity line(where it wants to go is sideLean force);
only Dutch low for limb sweep and high for top compression scenarios.
For sideways sweep, i once again Dutch block (downward) path force CoG wants to go and offer side path of relief reachable by CoG.
Similarly in top bind bucking; i Dutch block (upward) path force wants to go(high noon), and offer lesser pinch sidepath of relief (to about 1:30 of same 'clock').
In each instance this is a combination punch with the Tapered Hinge doing it's thang from opposite rear field.
This orchestration of force controls is very powerful dance to clean up/ballast sideLean force to target.
(realizing in climbing, the downpull of gravity is the sideLean to desired path; in top bind bucking most severe pinch is topside/consider as sideLean to desired path off to side at less severe pinch)
.
i don't ever try to spirit limb horizontal pure sideways 90degress from gravity forceFlow; always give some 15degree or so sliding relief drop.
This is consistent, with not really trying to play these games in felling with CoG greater than 75degrees from path; playing with power, don't go out of your powerband .
Don't go for the last 15degrees in either case; this is very powerful stuff, but so are the other forces!
 
Last edited:

TheTreeSpyder

Well-Known Member
#10
Not really magicians; but sometimes close enough to blur the line as we restrict almighty gravity to just a myth; before twisting it's straight line forceFlow to our arc-ed bidding to chosen target!
i think these simple forces are all around us; so generic they blur to the background and can't see them, but in trees we play with these at such a grand scale, is like viewing forces under microscope to see what has been there all along; then can find everywhere!
.
Certainly, certainly; the outer constraints are the genetics then the condition of the tree.
We view things at full power, to determine the range here; then define all else within those confines.
Weaker, more brittle Ash etc. would not hold itself to the works as well, would not give the leverage-able weight as much
>>and be more brittle to tension stretches and barberChair risks as well i think would be fair as examples.
In my area i look at Live Oaks as majestic, has all these good workable properties (and healths); glorious double cambium thick bark
>>but 'cheaper' made Water Oak locally, grows faster/weaker in trade(thin, watery bark); and in all ways only has a percentage of any attribute of my benchmark Live Oak
.
Perhaps ropes and pivots scream their lessons,but must listen with eyes, hands (not advisable in real time); leaving only some forensic artifacts/hysteretics footprints to trace. Except if can see deeply into worx with mind's eye('peer-a-mid power') or hopefully some sensitive devices still partially on horizon to more fully know these secrets.
.
Re-cap:Faced sideLean/assume some typical forward lean home/to target; tension safer than compression control
>>still maintain weightless tree
will dd the 1 CoG forcePoint to load system, defines pivot (first avail. support point) and thus CoG leverages:
BENCHMARK: compressed part of hinge as machine pivot/central works,is the most loaded machine part;
add Input Power Source: Leveraged forces of CoG;REALIZE contains forces that are pro, con or neutral to path across hinge
.
Break CoG pro/con/neutral package of forces of to 3 dimensions(really only worry about dim3):
dim1: part of tree weight that is inline with gravity to pivot (compressed part of hinge)
>>thus these loads neutral to the equation(no worries/neutral)
dim2: path across narrow/minimal support axis of hinge, that is also perpendicular to dim1
>>dim2 pulls home to target(no worries)
dim3: 3rd dimension perpendicular to both previous dims
>>sideloadings ; distracting other 2 dims forces from target(neutralize)
All 3 dims meet at pivot (compressed part of hinge)
.
Generally let dim2 forces carry self and dim1/neutrals home to target,
like a marble wants to lightly go where i want it to on board, simply let it!
>>dim3 distractions to marble; neutralize w/ballast of auto-adjusting Tapered Hinge pulling to opposing side (rear field)
>>Thus dim1 forces don't care, dim2 forces pulls hard home, dim3 forces neutralized from equation = marble rolls downhill happily to target
.
As long as machine doesn't bind at some point; should be good; working just the tension forces to ballast sideLean! (no wind, brushing other trees etc.)
Allows a smooth flowing motion w/o drama
Compression adjustments can actually be more powerful/but volatile/dangerous because can be unrelenting and can require drama to work best; and are powerful enough to violate tree container(barber chair), shift roots etc.
Compression adjustment strategies to sideLean typically have an early pivotal change(hard close) before can tear-off freely; that is VERY high impacting.
Like a pool shot get the most out of a Dutchman shelf 'bumper' by slapping purposefully, hard into the shelf for rebound response, not just lightly placing tree on shelf and allowing to roll off! CAN BE VERY DANGEROUS.
.
Tension gives much control, and shears on overloading; and leaves tree container intact; compression adjusts can take that further/tear apart tree, and can be combined w/tension adjustments
E=MCsquared; is speed squared; compression slap can use speed multiplier, tension control can't
>>speed squared makes speed most important part of force formulae in times of change
>>ALSO sudden change of pivot in mechanix on Dutch close can punch back hard into charging forward forces with disastrous results(barberchair).
(Tho in lower loading climbing and emergency sitback stop in felling :full face dutch can be friend!)
.
Most early Dutchman shelf compression closes are unintentional(scary),hidden(face within a face), full face(no relief path) and kerf-face(problems of no face + more lean + pivotal change + speed) = possible disasters.
If tree is not a non-binding smooth moving 'monolith'(1 solid piece) ; it can have multiple moving parts that can bind against each other and create Dutchman shelf pushes, even unseen, internally fractured parts can bind against each other with deadly results!
First, the Bad (Good/Bad/Uglies): foolish lil'man w/loud saw invading land of giants doesn't get to go home today!

.
What it is like to lose a crew member to this devil all too easily and accidentally conjured:
.
Surprise @1.30+ something bound some place and did not flow freely
.
Hidden, internal faults bind to BARBERCHAIR:
 
Last edited:

TheTreeSpyder

Well-Known Member
#11
To me BC is a machine overload from contradiction of seizing of unstoppable force and container of force/motor blows apart in split decision
>>before getting to this point, many things have a separation fuse of lighter duty to separate load from receiver.
>>in felling, controlling tension fibers and shearing angles across (not inline)can be this fuse
>>as well as offering other paths that maintain machine connection to more relief away from bind for raging forces to rush to flow to
Setting INLINE compression force X exponential speed multiplier and changing the machine mechanix w/o releif path can be hazardous!:
Also,it is key same mechanix aren't invoked by internal separation of parts, we want to worry about a single monolith, not separate parts jamming!!
.

.
i try to neuter-alize sideLean with 'weighted ballast' of Tapered Hinge tension (like sand bags) pull from start of motion
>> to leave easier forces of just a forward lean scenario.;
>>forward side leaner minus side lean is simple forward leaner>>cut and just let marble roll into hole nicely w/o sideLean dis-tracktions!
i see Dutchman as more of a compression adjustment to path already in progress(perhaps ballast action, but not a sandbag ballast device)
>>thus invoking confrontation of velocity squared with SUDDEN impact to change course of force flow
.
i favour Tapered Hinge as my offSide(Dent) ballast against sideLean (offsetting each other across pivot of compressed part of hinge)
>>sometimes this isn't enough and/or need sudden change to steer away from obstacle later in fall; so might add pepper spice of Dutch Step; but really mostly when can play to build more confidence using at smaller power scale of climbing cutz.
i visualize and show at full glory (and devastation) the full power extremes of felling as Dent's felling bible for most magnified view to explore;
tho have found more usage in the safer load ranges that don't BC of climbing and bucking cuts for the same Dutch step/shelf/tiered face mechanix.
.
A full face kerf Dutchman(accidental) has uses purposeful usages outside of felling , and not part of this example
(tho in sit-back backcut becomes full face Dutchman is anti-(further)-rollback safety friend ; that deeper face cuts reduce leverage of)
>>a full face kerf Dutchman offers no path of force relief only confrontation; step Dutchman offers offside as open path to raging forces
.
Not much written on this powerful path, some blurring of names
For discussion, correction etc. these are the names i personally know/call the 1 sided Dutchies things by(and some risks etc.):

.
Part of added dangers here are that to really use step hard you throw into it hard;
purposefully like needing to bounce cue ball across table from bumper, not just ease into it, and roll along it!
This makes this fast paced power, need to already know how you, saw, wood, helpers, legs, ground, shoes, shoelaces etc. react
>>in fast paced preciping on emergency circumstances
Far as i know there are no quick studies in that, literally takes a decade(s) of mean and stupid running at what most would have enough sense of running from.
Some lines you can't find except by crossing and then sorting their lessons i know;
>>but all is for naught if you can't make it back for another day!
 

TheTreeSpyder

Well-Known Member
#13
Very nice slo-mo showing rear tension pulls, rear fibers getting stretched hardest.
Last 2 don't have center mast main pull of balanced load.
2nd to last shows most signature high rear tension fibers to off-side Right
>>counter-ballasting sideLean Left, like weighted sandbags until tearoff
Can't decode last with twist , causing high Rights again,but seems balanced head, brushed neighbor that hard?
.
Have tried to show should have a side dimension in hinge/face for management of sideLean CoG
Watching 3 force points in rigid force container/domain of tree: CoG as initiating force,and then responding compressions and tensions w/their length/angles between these points.
>>Tapered Hinge gives 'cabled' 'weighted' auto-ballast from start of movement
>>Step-Dutchman is a later adjustment to path
Both Tapered Hinge and Step Dutchman give a side dimension of control against sideLean force
Just using Tapered Hinge as ballast to neutralize 3d sideLean scenario to a 2d forward scenario is more 'gracefull'
BUT speed-squared (x Mass) part of Einstein's Energy formulae makes Dutchman potentially more 'brutally' powerful; capitalizing on force that escapes Tapered Hinge ballast control, in some cases as an over-run control, and both strategies work well together many times. Also, for most magnified effect from Tapered Hinge we move slow, but for most effect from Dutchman we may look to multiply effect by fast movement; making even more dangerous in confusion and power at t he same time!
.
Dutchman invoking speed-squared force with impacting change, in full size felling is so powerful and then given no relief path(as in full face kerf Dutchman from crossed faceCuts) for the raging forward forces to flood to can lead to seizing and even corrupting container to BarberChair; this is no kid's game of pitting all of tree's force against itself until it comes apart!
But, if 'sitback', we do trust the resulting full face kerf Dutchman not to let scenario become a 'rollback'.
In other lower loading scenarios,mostly for climbers, full face kerf Dutchman can be quite friendly, even pre-ferred for staging up to cleanest, healthiest finishing cut in trimming.

.
Below shows why a tree 'picks' a round support shape for most even loading/least impacting across the leveraged paths across round support structure. How saw changes this support shape to having different support leverages on different axises across hinge. And some of the considerations of the shape and position of hinge. (F) shows a Full Face Kerf Dutchman as a safety, but then how a deeper face can reduce this safety, and wedge force leverage also.
.

.
In adding another 'forcePoint' of wedge push or rope pull, to the 3 forcePoints: CoG, compressions and tensions
i look to in general load more force across hinge during it's 'forging' to 'exercise' it stronger to target direction/not against 'anti-target' (sideLean).
Pulling with rope or pushing with wedge in directions to reduce side loading of sideLean, can 'forge' weaker hinge i think.
.
Also, pull/push leveraged force against sideLean would be that force multiplied by it's leveraged distance/angle more nominally against sideLean. But, use that same force volume input to force stronger hinge can stack the hinge leverage multiplier on top of the added push/pull leverage. So chains in another multiplier; and then persists until tearoff push/pull added to target when forging hinge,rather than exerting same force against sideLean.
.
Wedge push naturally stops when tree lifts, stopping wedge force input. You can still try to keep pulling rope,but if to face /target direction and tree is committed to target and will keep moving,rope pull is adding load against hinge support/weakening it to purpose of support, just like keeping cutting after tree will go where you want is weakening hinge control. Mostly look to force stronger hinge during it's 'forging' by exercising it stronger with greater loading, and then relieving extra load on stronger hinge; giving hinge more power band to manage rotation on hinge by massive tree.
.
i TRULY hope all the Dutchman pix actually serve as guide to why to make perfect square faces;
in felling as a forging against all the mechanics that can be conjured/invoked otherwise(especially accidentally)!
i like the force studies, and useful mechanix at lower loading ranges of climbing/bucking; not the full loading of felling. Simply seek to face to path axis; and handle sideLean across via countering Tapered Hinge tension as ballast to neutralize the sideLean part of force, and just leave forward lean scenario to target i think is best for felling.
.
In felling looking at why not to let Dutchman get invoked, especially accidentally (horizontal bypassing face cut), especially full face, especially by single kerf; and how similar faults can happen internally if cracked across path allows internal 'plates' to similarly seize/bind/overload across force flow path of fall that you must always watch for in the movement. You want the giant monster to move cleanly and smoothly away from you, so you get to go home that day!
 
Last edited:

Stephen Moore

Well-Known Member
#15
We's kicked this around elsewhere's; and to me, important enough to infect here also...
WARNING: long conceptual post ahead; challenging some popular concept's imagery
>>some would advise de-tour now ;brain in tact; instead of change everything!
.
Simplest CoG(Center of Gravity) expression: uniform log, balance horizontally @ CoG on vertical post ;
can view post as a needle exactly aligned to this center and so balances in this singular, unique point;
>>realize will fall in direction of CoG if post not lined up to CoG collective forcepoint.
Alternatively/just the same can take view that post simply divides log into 2 halves
>>each half exact ballast of the other at the CoG so log doesn't fall
Either way, the relationship between the CoG and support is ruling concept
>>the form/shape of log itself just offers positions to communicate to the CoG thru!!!
>>in electrical schematic sense, the CoG is the source/src active + voltage
while tree/rope is as weightless wire conduit (only here geometric angle counts) for the +CoG forceflow to the support's passive ground sink/snk!!

child's play :float pencil horizontal between both forefingers wide.
>>move fingers slowly inwards; 1 side slips, other grips as CoG between fingers adjusts to bear more friction on heavier side for pencil to grip that finger more and slide to re-balance until fingers are in center at CoG
child's play: grip pencil at CoG horizontally and shake up and down, looks normal
>>grip offset from CoG horizontally and shake and pencil seems to bend as motion is defined in pencil from CoG, not fingers!!!!
>>longer dowel, effect exaggerated; more distance input from defining CoG; imagine 'bending' 'proves' dowel weightless form of leveraged positions to confront CoG from....
>>eye sees, but can't define anomaly to brain, so we see the impossible pencil bend!
.
Concept: CoG doesn't have to be on a physical part of the device...
>>the CoG of a metal donut, is the center of the metal donut; in the hole itself!!
Here can see more clearly, CoG not on physical structure, but move structure/donut to alter CoG defining forcepoint position.
We define the CoG in the shape; REALLY should define the CoG position as point in space/time and then define the orientation of the weightless shape around the CoG!!
.
Center of Gravity (CoG) is such an unrecognized, invisible ruling concept of all motion and non-motion (secured) as well.
>>Trees growing larger/heavier than anything else; just express the concept more; revealing this life concept to treemens more than normal earth walkers!
.
In felling, rigging, growth etc. CoG is the sum total of all the weight and leverages of a device; expressed in 1 point.
i look at a tree, log etc. as absolutely a weightless form; with a single weight ball inside : the CoG
The position and angle of the CoG (within the weightless form) in relation to support;
ABSOLUTELY defines the leveraged angle and loading, where knots are tied, what direction knots are tied, how the device moves, impacts etc.
.
The angle of side lean from CoG to hinge makes the loading pattern in the hinge
>>this defines what areas of fibers are compressed;and what areas are stretched
>>maintain position of all and increase weight of CoG and keeps same pattern of loading in hinge; just more intense within that pattern
>>likewise, keep CoG same weight and angle(so mathematically same sine and cosine in this equation), but just change height(leveraged distance of CoG from pivot) and we have the same pattern of loading in hinge fibers, just different intensity of loading within that pattern.
.
If you stand in a light rowboat, it is much less stable
>>you have raised the CoG / making boat more tippable
>>BUT base of boat width is same resistance to tipping as when CoG was low
>>base width is anti-tip leverage, CoG is wanna-tip leverage
>>standing in boat makes wanna-tip leverage greater than anti-tip leverage
larger, heavier boat effect not as radical/or not seen; when your bodywieght CoG leverage is inconsequential to the weight/width of boat that then keeps CoG leverage low in relation to width/weight of boat.
.
In martial arts fighters squat to wider base AND lower CoG at same time for MUCH more stable formation
>>like pyramid; low balance;wide base is most stable.
>>upside down pyramid shows exact opposite in pruf;much less stable hi CoG,minimal base
.
Gymnastics hi-beam is meant as an expression of femininity:
The 4" wide beam is mechanically MUCH easier for the lower CoG and wider hipset of the female form!!
.
Soooooooo then a man more likely to fall out of back of pickup truck bed
>>CoG would be force to keep in truck
>>side of truck edge as forcepoint is keep-in-truck force line
>> would want to sit low; keep CoG lower than edge of truck
>>wimmen's is Naturally lower CoG
>>when taking boys to games etc. (long ago now) would teach/preach this is why to stay low in truck bed; keep man CoG (approx. solar plexus in male vs. almost hipset in wimmens in standard/leaner builds)
Large low gut can give lower CoG, but be harder on back cuz harsher angle from pillar of spine
>>it is ALL geometric architectural ; once't TomD quoted someone else (sorry fergit) that trees should considered as Bio-Mechanical devices
This rang true immediately and reverberated deeply thru for sometime until could hear in all the nuanceses even as the bell's tone faded: all life is subject being this bio-mechanical consideration; trees just exemplify this so we can see easier, cuz they are so big in ALL extremes!!
.
If take low weight off tree, can decrease total weight, but wait, lower weight was pulling CoG lower for more stable form! So could have worsened stability, tho decreased intensity of loading in that higher risk pattern.
>>BUT on some days this still gives GREATER leveraged load sum total from formulae of height of CoG from support pivot (as potential leveraged load) X sine of angle of same CoG to support pivot as a 'percentage' of the total potential leverage(cosine of angle would give inline loading 'percentage' of the inline/nominal/un-leveraged weight potential)
These lower wight changes can then affect height AND angle of CoG.
Compressed Pivot part of hinge carries the inline part of the load/tree
>>PLUS the leveraged part of the load
>>PLUS the resistance to the leveraged part of load/tree (from stretched fibers in hinge)across
note:compressed part of hinge is the most loaded, so is pivot
note:in my imagery force will run like electric force flow from CoG as source; trying for most efficient/laziest straight line path to defining pivot,and the straight as possible line to tensioned hold fibers
note: if hinge (or rope..) fibers slide thru a 'gradient of loading' from compressed to tensioned fields
>>then logically there is a most neutral field betwixt that is neither stretched in tension, nor compressed!
.
i think if rope meets log at CoG is only time/unique event that it is mechanically correct to only have running Bowline, Clove etc. holding.
>>ANY other time should have a Half-Hitch(HH) or Marl proceeding the anchoring runing Bowline or Clove etc.
>>further more the HH definitevely (and preferably the anchoring knot) are before the CoG position or HH can pull open; CoG again the ruling force.
Standing Part support is like fence post; needle should line up w/CoG or is mechanically wrong
>>more properly the Standing Part support, should line up with the CoG and then the securing other side of rope eye in straight line
If running Bowline to log load is not at CoG; the resistance hold securing eye will be at stressed angle/NOT INLINE
>>see how HH corrects this and places it's main resistance INLINE to Standing Part as support
>>see how HH is simply a modifier of the force flow that is now correct

Note how especially in #B the securing rope stop opposite Standing Part is also best Nip
>>because of consistency of these principles!
.
This is how much (and then sum) CoG means to me in all aspects of life'smechanix all around us let alone expressed so visibly in all that we do! Every tree, every rig, every step we take, every fall we make!
.
Have tried to show if connected, the relationship between supporting connection and CoG is the TOTAL ruling concept.
>>But even when free agent/log falling/no supporting connection the CoG rules!
If hit enough force at CoG would push free float log inline back/up whatever equal/opposite direction
>>but if hit free agent log below CoG can log can spin rotation down, if hit above CoG opposite spin
If CoG not connected to support pivot; CoG itself becomes the most loaded point, thereby the pivot!
Weightless shape just carries around the CoG forcepoint as it's pivot!
Weightless shape is just handles to talk to the CoG forcepoint thru and CoG to comm(unicate) it's forces back thru!
.
CoG rules!!
orrrrrrrrrrr these would fall like eye says should!!!:

EVERYTHING else is the same!
Tree work just so much mor1e intensely due to the scale of weight/length/rigidity that these same ruling props are expressed by!
As treemen we get this gift view of life concepts as few other see; so large on our stage,we must be in front row to see what many others miss as part of our bounty!
.
i truly believe, if'n you can see a rig or a tree felling as weightless forms with CoG's to pivot schematic in head; it is easier and more intuitive to innately make the right mechanically correct moves!
Grooming each laced knot like a craftsman making an architecture to these most raw and correct defining concepts.
.
orrrrrr something like that!
(sorry so long,but BIG concept, BIG implications all the way thru safety handling / predictability etc.!)
You can use a modified timber hitch, provided the rope is long enough. It wont slip ever! I've never seen one come loose in 12 years.
 

Stephen Moore

Well-Known Member
#16
Dutchman is sloppy workmanship. A small one only serves to prematurely break the hinge on that side and cause pull toward the anchored side. I can do that by properly gunning my undercut if I need to steer my tree. A deep Dutchman can stop the cut progression completely and change forward momentum into tension potentially causing a barber chair, more often than not it causes complete loss of control because to fix it the sawyer needs to quickly cut off his holding wood to relieve tension. Bad Bad Bad. In one of those videos, I cringed at the size of the undercut? WTF why didn't his partner ask him to widen it and then check to see if the cuts were clean and exact? They work together, they can die together... safety is the responsibility of every person involved in the task.
 

TheTreeSpyder

Well-Known Member
#17
i advocate looking at Dutchman forces at full felling force to understand mechanics at this extreme magnification for better viewing.
But, in felling hope these lessons actually show why to perfectly and purposefully machine the faces correctly, as to not accidentally invoke these mechanix.
In some felling shituations Dutchmans do have their place if purposefully well placed etc.
.
Mostly have found use for same science used in climbing and bucking as very useful; and not to the full dangers of the fully loaded falling of a tree where the forces can 'over rule the constitution of the spar/container' as no other felling strategy is powerful enough to do!
.
Step Dutchman that tears off it's side only and pulls to Tapered Hinge side; Dent's felling bible describes as a Swing-Dutchman; tho a very dangerous move; there is judicious usage.
****************************************************.
i think this is really all math; each thing you do/don't do during setup gives a logical instruction to the mechanix that plays out when light fuse/backcut enough to set to motion.
.
i think hinge strength is forced or 'forged' by the FORWARD pulls to target;
then spar rotates on hinge with that strength setting of hinge.
We can fake load more forward force with wedge/rope devices to exercise /forge hinge stronger while backcutting.
But, then favour stop pulling rope when tree is committed, for this would be extra load against said hinge strength, operation is in a different phase now.
.
i think it is best to teach eye what is really happening in this math, so gives more of true vision when sees something and hands off info to brain.
Might have to crunch some numbers to catch the rhythm of the flow of forces.
>>but in actual usage usually just need to remember benchmarks, patterns, redlines etc. once have looked at closely enough to get a fair grip on what's happening.
.
The ancients decoded this and handed it down after cracking the code for us!
Everything has a finite length and force
cosine (columnSine) is simply 0-1 'percentage' of length/force in a column/line between forcePoints
sine (sin) is the non/anti flow perpendicular to the straight and narrow path of the columnSine.
orrrrrrr something like that!
.
angular_force_potentials.png
 
Top