What is the Loading?

[MasterBlaster]

Originally posted by rbtree
with the troll?

http://www.zverina.com/z981116.htm

Trolls have no manners. They NEVER pass it back!!!

 

[glens]

Originally posted by Mike Maas
OK, I get it now, ... all this force is just sitting there ... doesn't change the output. It just changes how the rope is attached to the log.
This is why Spiders lacing doesn't help the pulling power of various configurations.

Exactly.  It's like trying to get pregnant by mutual masturbation in that the devices are being used in close proximity to the necessary interfaces, yet exclusively and independently.  As I said previously somewhere, if the felling cuts were somehow included inside the mechanism Ken would be on to something.  It's like he's got a mouse trapped under a glass with a 2# weight to hold it down, but the weight is also working through a series of levers to balance the Boeing 747 he's brought in and set beside the glass for some unknowable reason.

I want to correct a statement I made earlier in this thread.  I didn't mean to make it sound like there's 400# of tension on the inner end of the rope where it's fastened to the object.  After the circuitous route, the rope still only has 100# of tension at that point.  He's only got 300# of downward tension on the top half of the object, so the answer really is that it's a 3:1 MA.  Thus 300# on the lower strap due to the "masturtension" plus the "machine" weight of 100#.

Mike, get a load of this:<blockquote>"Although the primary function of some machines can be identified, it would be difficult to classify all machines as either force or motion modifiers; some machines belong in both categories.&nbsp; All machines, however, must perform a motion-modifying function, since if the parts of a mechanical device do not move, it is a structure, not a machine."

<i>Machines and Machine Components</i>, 11:232b, Britannica, 15th Edition, &copy;1974</blockquote>Glen

 

[glens]

Originally posted by TheTreeSpyder:
So the 100# freee hanging load has 400# pushing up on it! Like i said a good attention getter for HS talk about climbing and rope sense, the ways you can use it, what to watch out for etc.


Or something like that
:alien:

Look, Ken.

I guess my point by all these mental gymnastics is to hopefully get you to see that your bringing such concepts up to strangers is really a source for embarrassment.&nbsp; Please don't set yourself up like that.

The 100# free hanging load has nothing pushing up on it.&nbsp; In order to appear as a hanging 100# load while having 400# pushing up on it, it would need to weigh 500#.&nbsp; But then it would not be <i>free</i> hanging, would it?

All you've accomplished is getting a 100# load to hang, and while so doing, apply 300# of potential internal compression to itself, thus uselessly (and carelessly?) stressing the load-carrying point to a much higher level.

Glen

 

[TheTreeSpyder]

i think that the 400# is pushing up, the 300# is pushing down; to leave 100# support for the 100# weight that powers it all.

Whether because the extra loading leg gives more structure-a solider fell, or more arc-ing on the hinge as i say; i notice an elusive , helpful differance in the arraingement.

i think that specifically in the self tightening/torquing load that the power i speak of is evident; i've been using it a long time, tried to describe on ISA board maybe 5 years ago. As i watch, the more loading on the line off of the hinge, the more the line wants to uncurl and dump the load; i think that is just a characiture of Nature wanting to relieve the higer than necessary loaded rope from the turn on the load. If in such relief it is scheduled to move closer to target, that is great; if the load rotates in force to do that that is an arched, non linear, slower than linear, leveraged force of movement to target i think.

Nature's orchestration and rules are perplexing, a true challenging puzzle on their own.

 

[glens]

Originally posted by TheTreeSpyder
i think that the 400# is pushing up, the 300# is pushing down; to leave 100# support for the 100# weight that powers it all.

That sounds rather backwards.&nbsp; You have a superfluous 300# pulling down from (near) the top and a superfluous 300# pulling up from the sling attachment point, both forces canceling out somewhere in the middle.&nbsp; Beyond that, the weight of the object, 100#, is also concentrated at the sling attachment point.&nbsp; So yes, there <i>is</i> a 400# force on the sling attachment point, but 100# alone would entirely suffice for any real and reasonable thing you want to accomplish.&nbsp; Moreover, the 400# is technically <i>pulling up</i> against the attachment point.&nbsp; If anything can be said to be <i>pushing</i> with 400# of force, it would be the material in the object pushing <b>down</b> on the strap anchor.&nbsp; But saying it like that way don't sound too well.

Whether because the extra loading leg gives more structure-a solider fell, or more arc-ing on the hinge as i say; i notice an elusive , helpful differance in the arraingement.

The "extra loading leg" does absolutely nothing except tie up valuable resources and possibly even serve to compromise the structural integrity of the object.&nbsp; We're not talking about pulling a stem against a hinge in this exercise -- this is a free-hanging weight.&nbsp; But let's extend the concept of pre-loading the stem against itself to pulling one over.&nbsp; If both rope contact points are above the hinge, of their cumulative compressive forces all but that which would be present if the rope were merely tied to the top will cancel out somewhere between them.&nbsp; Nothing of the extra effort will come anywhere near the hinge.&nbsp; The hinge won't have a clue that anything more than a single rope tied to the stem top is pulling it both down and to the side.&nbsp; Furthermore, just as soon as gravity accelerates the stem to the same speed the rope is being pulled, the rope will have no effect whatsoever in "arc-ing" the stem "on the hinge".

Your quoted material just fixin' to come is extremely hard to follow...

i think that specifically in the self tightening/torquing load that the power i speak of is evident; i've been using it a long time, tried to describe on ISA board maybe 5 years ago. As i watch, the more loading on the line off of the hinge, the more the line wants to uncurl and dump the load; i think that is just a characiture of Nature wanting to relieve the higer than necessary loaded rope from the turn on the load. If in such relief it is scheduled to move closer to target, that is great; if the load rotates in force to do that that is an arched, non linear, slower than linear, leveraged force of movement to target i think.

I'll try to address all of that specifically a little later this evening.&nbsp; As an overview, I'd say your argument sounds similar to the many ways people will claim they cause a motorcycle to turn at road speed.&nbsp; Some just lean, some press against the side of the tank with their thigh, some shift their weight, etc.&nbsp; But once they learn that the actual thing they're all doing in common, the only thing that effects the change, is pressing the handlebars in the opposite direction, they discover the puzzling mayhem of it all just disappears and their control and precision increase dramatically as they cease the unnecessary behavior.&nbsp; Not turning quite fast enough?&nbsp; Just press harder on the "wrong" handgrip.&nbsp; Do you see the correlation to your situation in that example?

Nature's orchestration and rules are perplexing, a true challenging puzzle on their own.

I think they're somewhat less so than you're making them be, Ken.

Glen

 

[TheTreeSpyder]

i think the loading takes place in the lacing pattern on the load as well as it would in any other fashion. It is just like the load was hanging to power a 5/1 lift, compression, scinece project example on a piece of plywood etc. all the same. My point was that it is built up, i think i have been using this for years. The puzzle i dreamed up from watching my own rigs as i was doing this Leg on Load thing, and feeling real good about it.

So when i suggested puzzle for High School talk on amazing rope force ya wouldn't believe for an attention getter, then wrote about using the same principal for rigging etc.; it was because i've been using it for years, and thought i had a good example to explain it by; but then i thought we all would see puzzle the same pretty much right off.

One point in having extra tension for the same work is that Nature don't work like that and will want to releive the situation to the minimal loading per load. With a line, that means hanging straight unbent. i think that is what extra force is for when ya have the load pressing down forcing line to support at an angle, to have enough force to support the load, and power the sterring around, cuz i think it takes more force to turn, so that would balance out (?)

 

[glens]

"So when i suggested puzzle for High School talk on amazing rope force ya wouldn't believe for an attention getter, then wrote about using the same principal for rigging etc."

LOL, if you wrote a paper for the science class, they probably forwarded it to the English department, where there'd certainly be greater (initial) interest. <font face="fixed"></font>

I've made some notes on your image.&nbsp; I'm sorry it doesn't work better.&nbsp; I initially used a larger font at the top center; then top right; then switched to a smaller font, underlining, and arrows to comment on the text.&nbsp; I recommend reading the notes in that order.

I didn't comment on most of what you wrote because it looks right and/or is (so far as I can tell) tangential to the root of the topic.&nbsp; And I really want to say that I don't intend to come across as trying to teach you how to rig tree parts.&nbsp; My involvement mainly focuses on helping you to understand that some of what I see you're advocating is extra work which has no real benefit (at least in what I see you drawing and hear you saying), and may in some cases be detrimental.

I really think that if you saved your work initially in GIF format, detail would be better preserved (especially in subsequent use) and file sizes might be smaller to boot.&nbsp; This one is now about 3 times the size I like for dial-up use.

Glen

 

[TheTreeSpyder]

Alright guys, even though i have been using it for years; i can see where it never worked........ i guess ye will stand in your corner of the world and do as you will; and i likewise occupy my corner tied up as well.

 

[glens]

Nobody is saying you haven't been successful.&nbsp; Just that, well like in the movie "The Princess Bride":<blockquote>[Vizzini has just cut the rope The Dread Pirate Roberts is climbing up]
Vizzini:&nbsp; HE DIDN'T FALL?&nbsp; INCONCEIVABLE.
Inigo Montoya:&nbsp; You keep using that word.&nbsp; I do not think it means what you think it means.
(<a href="http://us.imdb.com/title/tt0093779/quotes">imdb.com</a>)</blockquote>Really, Ken, get on a motorcycle and get up to about 25 MPH, then push with your left thigh against the tank and watch yourself go right.&nbsp; Then, take your hands off the handlebars and try it -- nothing happens.&nbsp; The additional thing done to achieve the desired result didn't hinder the result so long as the actual cause was put to service, but in reality it didn't affect it either way.&nbsp; The motorcycle will turn right if the only thing you do is press forward on the right handgrip (or pull backward on the left) or add any number of gyrations to that action.

What happens when you suspend a twig that balances at the crotch both by directly fastening the line there and by lacing it?&nbsp; If it hangs the same both ways (hint: it does for me) then the laced leg, though certainly imparting some forces, has no effect on the outcome.&nbsp; The forces involved within the leg are fully self-contained.&nbsp; The leg adds no stabilization or torque response; it's merely a length of line pulling against itself and not being productive.

Glen

 

[TheTreeSpyder]

Thanks for tip on .gif, works much better; Mike or anyone else messing with drawings sometimes for minimal size should take note. i must totally agree on motorcycle steering 'phenomenon'. i kinda been telling that one for 20 years, year round riding down here. Very nice to throw bars away to the right to lean left to trace inside curve of lake looking down right side to see lake like out of a plane so far leaned over; then bring the bars back up under ya to straighten; really use that swingarm. i think of it as bouncing off the gyroscope of the front wheel as ya lean CG over to new path, then get rest of bike to it.

To me a natural fitting with the gymnastics, rigging , climbing for trying to reach effortless, balanced force of power and grace by walking that balance.

i can't say that i have named everything right, but don't think i'm far off. ~10 years ago this guy i climb for from time to time started getting rental personel, then placed all his guys under that umbrella to cover Workmen's comp etc. As it all was phasing in, any worker on a roof became more of a problem, for the personel company didn't allow that etc. This was evolved for taking branches over roofs whole in one sweep, that wouldn't seem likely otherwise without similar tension from lift from GRC$ or other rig from above, rather than from gravity below, but to same end? (Kinda mighta stole that line from Murph, talking about Big John's strategies).

 

[TheTreeSpyder]

Rock Around the Clock strategy that works well without bend, seems more intense with.

i've used this for best control, control when i wanted a left support and only had a right one; on occasion i have tiptoed around an aluminum antanae when no room to lift, and trusted no other method.

 

[TheTreeSpyder]

Extra time for application has been brought up. Some learning curve etc.; but sometimes it saves time. Especially as a better transitional strategy from rig to rig i think.

As far as the line loading goes, here i claim more tension on the line; but try to deal with no impact on this super self tightened line. i think the trade off would be less loading. For, i've seen force quoted here and else where as being (speed x speed) x (weight/2); so the increase at loading through weight not speed would be less(?)

Here the climber can save a lot of time, be safer etc. working the trunk line, and still have well leveraged hitch points on the bigger limbs. The strategy also uses overhead friction and a high angle support, with most of the load down the pillar strength of the trunk i think.

 

[BigJohn]

whats the top pulley connected to? what keeps it from falling? Is this a trick question?

 

[TheTreeSpyder]

All pulleys mounted to load. After rigging this way succesfully, the idea that even though it didn't seem possible to build force higher than the load, from the load hanging on a single line; on the load itself, but it happens like that.

It has served me very well rigging. One of the ways i feel it does; is by raising the tension in the system, higher than necessary, and nature seeks to relieve, i make the releif of pressure that line seeks to be on the path to target. really the same strategy we use in other things, just applied here. Taking a face cut provides a path to least resistance (into face), a slanted line, puling with a line etc.

Orrrr something like that.
:alien:

 

[glens]

<blockquote>"i think the bend raises tension Nature would like to relieve also; but only does it at one point; not to the whole line or either leg.&nbsp; But a slanted line does, so the slanted line multiplier of what the line needs to maintain the given load on a straight line; is fed into the multiplier for the bend; for higher loading at the bend"</blockquote>Well, yes, sort of...&nbsp; The extra loading at the bend accomplishes nothing, however, beyond placing more stress on the line than is needed for the task.&nbsp; It's not that much, though, so it probably doesn't hurt anything.

The line in your bottom-most scenario image would impart an amount of torque to the limb which would be the same, for the first 180&deg; of rotation, as if you'd merely wrapped the limb a couple of times.&nbsp; So unless you intend to rotate the limb 270&deg; or so, there's nothing gained by doing what you've shown.

Other than the "Bends" section of that image/documentary, you've done a very good job of illustrating what happens in each case, and you actually used the language we all speak! (unless I've become accustomed to your dialect, hahaha).

Congratulations.

Glen

 

[TheTreeSpyder]

Originally posted by glens
Well, yes, sort of...&nbsp; The extra loading at the bend accomplishes nothing, however, beyond placing more stress on the line than is needed for the task.&nbsp; It's not that much, though, so it probably doesn't hurt anything.

Other than the "Bends" section of that image/documentary, you've done a very good job of illustrating what happens in each case, and you actually used the language we all speak! (unless I've become accustomed to your dialect, hahaha).

Congratulations.
Glen

i think the extra loading at the bend is more of an active force as movement starts and things change. Also, i think that given the property that Nature wishes to take the path of least resistance, the bend that increases the loading at that point, by any factor would make the bend want to come out. the line wishes to be at the position of least loading if possible(and if the line can find a way to get out of carrying the load at all, the load drops), straight in line with the pull, in this case gravity. Any slant or bend leverages the line to a higher, possibly unnecesary/un-secured loading, that Nature will seek to releive if possible, and thru the leveraging has the power to do so, and maintain the load too.

i am working on the lingo, a translation from the re-re-re-adjusted cartoons drawn in head to make decisions by over time.

-KC

 

[TheTreeSpyder]

A different view of a bent line pull, whose positions and pulls are not all equivalent to each other, and i think that adjusting the CG across the width of the board would also influence the outcome in not moving at all, or the force of the subsequent motion of the board flipping.

When i lace one of the bent line on load to aid turn strategies; i try to sweat as much purchase from the line as possible, to turn any motion down into immediate supporting pull. Tight enough that the load can't go down; then face cuts to the target, sometimes dutch kerf in face on turn from side. Then in Backcutting, instead of cutting across to target, and bearing weight and turn on hinge; i cut towards down as much as possible to load the line as much as possible. This raises the total line tension, that is then multiplied by whatever slant, then increased pressure at bends less than 120deg. So feeding down at first empowers the turning power of the line more, thenit can assist, even force the hinge folding (for stronger hinge) as you tilt the saw to cut more on the across axis towards the real target. With both the line and the hinge maximized; and their forces automatically set by the load itself.

 

[glens]

Whoa!&nbsp; Your language is regressing there, Ken

As far as strictly rotational influence is concerned, A, B, and C are all exactly the same for the first (almost) 90&deg;, at which point will it only then become "apparent" to the rope that it might be able to have continued rotational influence with A and B.&nbsp; B would cease rotational influence at 180&deg; and A would be able to spin the board to 270&deg; while having more leverage against it through the range between 90&deg; - 180&deg; than does B.

How much do you rotate material while pulling it, anyway?

When figuring torque at any given position, you must take the distance the line is from the center of rotation, being sure to find the effective radius for that position by extending a line through the rotational center parallel to the pulling force and measuring the distance at right angles between them (in the plane 90&deg; from the rotational axis -- if the rotational axis is fully parallel to the pulling force, there will be no torque about that axis regardless the distance between them).&nbsp; Where the rope goes away from the pulling force beyond that tangent point is immaterial until/unless the rotation continues.&nbsp; Only in that case do you then figure the new tangential distance at each subsequent point.

&nbsp; orrr, something like that&nbsp;

Glen

 

[TheTreeSpyder]

This was something i did a while back of an assembled set of systems in a rig to tackle a large fallen tree in a bad position; and a chance to try my branch rigging strategies on a lot larger scale.

i had to tie back the support tree bearing the 15 x 1 x 3pullers. The angle of the line pulls back into the stump for
Hinge Pocket Pressure Rig effect sprinkled in. Notice if the CG/C.o.B. was inside the hinge to hitchpoint region, the pull would have been down on fiber holding to stump. The lead man on the crew i was working with, wanted to cut off a bunch of weight from the far end when i stabilized the bracing before movement to help. i think having the CG on the far end kept butt end from ripping down stump. That and wanting to smash out flower pot after after column was loaded with weight of tree pressing down as it tried to pass across i think could have changed the whole day in the wrong direction.....

i bring this up here, because there was a small bend to get the tree to shift in direction of choice in the line at a 10x 3 guys point. This gave a lil riding up of the load (to many's surprise)as i tried to express with branch riding up as pressure torques on it, but cannot flip as in "How i Used" Diagram as it twisted slightly up and pirhoetted around over the short ornate wall in 1 Shot over Wall that someone reminded me about late last night picking at my head.

Pressure is pressure, usually i try to invoke these things as gravity pulled down, here i invoked pressure at bend as i pulled up; but it is all the same i think, just the tension arrived at from a different direction to the same result i think. i don't think that the system would have worked otherwise, as the 'hinge' seemed to want to steer the opposite direction; i think the locked bend trying to escape overpowered that directional influence to success.

Or something like that
:alien:

 

[NeTree]

This was fun.