I don't know if I figured this out or learned it in a felling class or reading...my plan:
Two parts...in front of the hinge/apex and behind the hinge/apex.
Make the face directly towards where the tree needed to lay. Use an open face.
Add force on the area behind the hinge to act on the off-balance. Usually, mostly, that force would be a pull-rope with a piggy backed mechanical advantage system on the pull rope. The pull rope was anchored to an FOS bollard or similar. The direction of the pull was more art/judgement than science. Also, practical. Where is there an anchor? At times we'd create anchors by stringing ropes between trees or trucks and attaching the anchor mid span. The belt of the system.
Wedges were used more to capture any gain in the back cut rather than counted on as a lifting force. The suspenders of the system.
Bring up the back cut and take stretch/slack out of the pull rope. Keep the hinge connected as much as possible. We called this 'ripping the hinge' on the crew. Use the strength of the fibers to hold the tree onto the lay.
This sure isn't a system that's much different than a lot of people use. Nothing really new I hope.
I would add that depending on the severity of your side lean you my need to sight your undercut past your intended lay to over-compensate for the side lean. Much like judging the direction of your pull line, this is an art/judgement thing that becomes a science through experience.
I mostly wedge as anti-sitback I think as Tom says.
We called 'ripping the hinge' as muscling over or arm wrestling tree.
And yes need to capture your 'purchase' for safety.
Tom w/gymnastics and all maybe we went to different schools together!
Over time came to visualize added force to forward side lean as either babying or strengthening hinge. Especially with Tapered Hinge as side ballast , I look at force forward into face to make thicker hinge like tree is heavier.
Then thicker hinge as leverage against side lean until tear off.
Part of force used instead to ballast against side lean.
Result after temporary wedge or rope input relieved:
Forward force input:
Hinge forced thicker , by faked like was heavier, now thicker hinge per load after input relieved
Anti-side lean force direction relieved can allow side lean to impact back
Input wedge, rope forward are purely across thinnest axis of hinge/path of least resistance .
Temporary input against side lean are against/have to pass through long , leveraged axis of hinge.
Especially on sidewards sweeps of downward force and across path, as most sensitive barometer of this quotient.
I know what y'all mean by feel and art as far specific direction.
But personally came around to not fighting side lean directly with any part of pull, but rather pulling straight for super hinge and then hinge as another leveraged multiplier (rather than nominal input), that then persists against side lean beyond relief of wedge/rope input. Side lean doesn't impact back.
But anyway you go I think direction of input force is an important/not as generic topic as sounds.
Dis-allowing backleaners, rope pull model only(to simplify):
Tree spends more fall time w/o rope pull than with (unless 'muscling over'/arm wrestling tree down)
Tree rotation, gradually increases leveraged load against pre-set hinge.
>>Essentially tree is heavier on same hinge every degree forward.
>>If tree lean started heavier forward, forces thinnest part of hinge profile to grow thicker in response
>>rope pull forward spoofs system to thinking tree is heavier, makes beefier hinge in response
Tree rotates 1 degree, and is now leveraged heavier against, a beefier hinge more prepped for it.
So see rope pull as exercising hinge stronger until 'first folding'/start of continuous motion.
>>on relief of forward rope pull, reaction would be for system to press back a pulse of force against tree for more support w/impact.
Some pull against side lean, takes some pull away from hinge thickening.
>>and gives temporary support against side lean.
This is opposite strategy of exercising hinge stronger during it's 'growth'/forging w/extra load
>>to babying hinge temporarily during forging by:
A>taking away some forward force to make stronger (forward consideration)
B>and presenting less leveraged load, not more to start(sideward consideration)
On relief of forward part of pull across path of least resistance /narrow part of hinge
>>impact of change pulses back against w/inertia against tree fall for more support of less load than started with
On relief of sideward part of pull across path of most leveraged resistance on long axis of hinge
>>impact of change pulses back w/inertia to increase sidelean force with more than started with when rope pulling sideways(back to original/Natural value)
30 degree 1 o'clock rope pull against left sidelean(12 noon being forward pull benchmark):
>>86.6% of rope leverage pull goes forward to strengthen hinge (cosine(.866)
>>50% of rope leveraged pull goes sideward to baby system/relieve sidelean(sine .500)
(then sidelean impacts that load back when rope pull stops)
In strip hinge, forward force to strengthen/not baby effect would be more nominaly adding leveraged layer.
But in Tapered Hinge use of mostly just fattening the 'off side' countering sidelean reducing forward pull reduces much more leveraged multiplier potential against the sidelean
Rope pull is just prep of hinge, tree spends more time on hinge,than on rope pull.
Sometimes seems like need to reel in some of side lean, and initiate movement inertia with less sidelean to then hopefully carry forward the same forwardness thru motion once started
>>And this is fine if this effect can match/over-rule any impact back to original sidelean value effect when rope pull is relieved....
(i always have to prove theories to self in tree also)
Horizontal rig limb gives most leveraged angle of sidelean load (down) to the across target path of hinge(like felling hard sidelean)
>>hinge thickness is totally set by, and movement initiated by pulls across thinnest part of hinge to target
no/not enough sidepull and end up walking hinge so thin fails down, not folds across.
anyway, that is how i came up with this theory/, or considerations on how it can play out sometimes etc.!
In this situation I will often use a pull line at 30 degrees or more overcompensation to generate the motion and vector, and a strong arm to keep the the trajectory after cog starts to change as the canopy comes over. This is only in spreading canopies without great hinge. Most hardwoods will swing without the strong arm and an open face notch/tapered hinge, but the strong arm can also be useful to keep it rolling back towards the heavy side if you don’t have some good kickstands in the structure after the hinge severs (if it does- usually does in this situation).
I have experimented with a side pull line that is anchored even with the stump(and even some behind) and perpendicular to the intended lay. The vertical height of the side lean correcting line in the tree will equal the horizontal distance of that point from the stump when the tree is on the ground, minus the height of the felling cut. The height of the felling cut results in less tension on the spar as the tree closes to the ground when falling. To keep constant tension in the side lean weight correcting line it's anchor point needs to be behind the tree stump equal in distance to the felling cut height(this line I usually run at a 45° angle).
Side guide line or wedge but usually the longer and flatter the pull as long as it’s bigger and stronger than the resistance pull and weight should overcome any lean. Some times if it’s bad and I can a guide rope from either side to cradle it while pulling is a good way to go.
Also a directionally aimed back cut with a left over pie shaped hinge helps
For years i worked it as Mitch. and many other.
i too have played withe the off-side line limiter to the rear a'la'TreeCo, sometimes thru a 10-15' high rear crotch then anchor down load on further back anchor.
>>Is part of my pruf to self of Tapered Hinge as similar offisde limiter of binding fibre against sideLean for full tour on hinge,built in to hinge.
>>Treeco's side limiter also gives high leverage line sweat/leverage point(s)
(hope everyone knows that is no suggestion to do, as is crazy-azz dangerous; keep pulling that lion's tail and it will bite ,and when line snaps lethal recoil like rocket launcher destroying anything in front or behind- on that loaded axis).
i think that if you can maintain the side limiter/offisde pull the whole tour on the hinge with rope @ full tension>> isn't scenario i saw most outside of limiter model.
Normally; just as when tree lifts from wedge, when rope slackens even some; then loses side ballast/limiter control and depends on what was 'programmed' or built into the hinge/face machine etc..
i think should mostly target force thicker hinge with all force forward, then use Tapered Hinge as a further stacked leveraged multiplier of control increased by the thicker hinge, to control as TreeCo's side limiter; but built into hinge. Whereby forward part of pull thus exercises hinge stronger,and hinge pattern leverages side control from that stronger hinge forced.
i visualize forward force across thinnest part of hinge/to gunned face as exercising hinge stronger; as artificial load, that is then relieved when tree moves and hinge strength set
Where as pulls across, somewhat across long length of hinge could then ballast against sideLean as hinge was 'forming strength' to 'baby' hinge, rope or wedge slackens on tree movement and that relieved quantity jumps back in impacting to more loaded now just as tree moves .
Pulls across thin part of hinge to gun>>thicken/strengthen hinge if not backleaner.
Pull percentage against sideLean takes that quantity from front pull to thicken hinge
>>And lessens side load as hinge forms/not increasing load as front pull does
>>forward part of pull when relieved impacts back with more support against fall
>>side ballast part of when relieved impacts back with not more strength, against fall,but original sidelean 'bouncing' back in, impacting to side as travel starts.
Percentage of forward pull lost by pull at angle could reduce hinge strength, therefore reduce tapered hinge multiplier and limiter, then impact back in against weaker tapered hinge on thinner hinge.
Side pull rope that isn't a limiter whole ride is a temporary input as wedge usually.
Increasing hinge thickness to make even greater tapered hinge leverage multiplier could persist further w/more force of control, into Mitch's more open face(in favorable woods) w/Treeco's side limiter built in (model).
Especially pronounced in tree test of scenario turned sideways for horizontal long branch sweeps.
>>Force puling into face makes stronger hinge>> shape for job and use thru sweep.
Treeco in 3 dimensions i see:
>> inline to support pivot as neutral balanced, bank of forces(telephone pole) that could feed to other 2 leveraged dimensions of lean during fall
>>stresses against thin axis of hinge forward
>>and stresses against long axis/part of hinge to side
I forgot about that... as Useless Info is saying, your pull line can exert downward force on the lean with too much pre-tensioning and cause your cut to coosbay at the point where you want the line generating a little lift. Really bad outcome in this situation, as it’s usually almost perpendicular to the intended lay. I’ve seen it happen when pretensioning with a machine. Another scenario where Bluetooth saves the day...