boker reality based folder any good?

[Thomas Linton]

Why would it be absurd? It would be the stiffest (which roughly means strongest) it has ever been, right? A stronger and lighter blade is somehow completely absurb?

It is the shape that produced the effect. That requires some material be removed and that some remain. No material = no shape.

That there are limits to how much material can be removed does not invalidate the engineering principle.

Another example: within limits, a pipe is stiffer than the same mass of the same steel in a rod. Reduce the principle to the absurd and the pipe walls are foil thin and cannot support the pipe's own weight. The principle is still valid within practical limits.

As I, understand it, "stiffness" as used here = resistence to bending.

 

[kel_aa]

Even if you could make a blade like that, could you carry it? And if you carried it, could you find it in your pocket when you needed it?

I said infinitismal with respect to mass. Who said it had to be short? Does a fuller make a knife shorter?

 

[kel_aa]

Okay, thanks Thomas and Pahtoocara for a civil discussion. I just hope non-one starts grooving their house's framing lumber to improve the strength of their house.

 

[Pahtoocara]

The blade of discussion needs to be tested to see if the fuller is actually functional in some regard. If the theory (as stated in the knife description) is that it's a blood groove :barf: then stab a dead animal and see if there is a difference between this knife and a similar knife in retraction.

Another example: within limits, a pipe is stiffer than the same mass of the same steel in a rod. Reduce the principle to the absurd and the pipe walls are foil thin and cannot support the pipe's own weight. The principle is still valid within practical limits.

Mr. Linton, your on the money!!!

kel_aa "infinitesimal mass" would be approaching zero mass....zero mass would be non-existant. In other words, it's so close to zero it might as well be zero. I'm not a mathematician so this is my best explaination. This would be near impossible from a practical standpoint.

Okay, thanks Thomas and Pahtoocara for a civil discussion. I just hope non-one starts grooving their house's framing lumber to improve the strength of their house.

This may not be the ideal configuration for (let's say) a 2x4, but they do do this with other materials besides metal.

 

[wwells20]

Okay, thanks Thomas and Pahtoocara for a civil discussion. I just hope non-one starts grooving their house's framing lumber to improve the strength of their house.

I admit to having nothing to add to thread, but this was just GD funny! Thank you for making me LMAO!

 

[Thomas Linton]

Okay, thanks Thomas and Pahtoocara for a civil discussion. I just hope non-one starts grooving their house's framing lumber to improve the strength of their house.

Manufactured I-beams of plywood have been standard construction material for residential structures for over ten years. So I fear it's too late for your warning.

 

[kel_aa]

I'm sorry that you cannot distingush between having a structure designed around using I-beams of plywood and someone taking a gouge to their house's 2x4's to improve its strength, as fullers obvious do.

 

[kel_aa]

Okay, let's try this: take beam A and B of the respective cross sections:

A.................B

XXXX
XXXX...........XXXXXXXX
XXXX...........XXXXXXXX
XXXX

They both have the same cross sectional area, 16 sq units.

Which beam will be stiffer when loaded from the top surface?
Which beam will be siffer when loaded from the side surface?

What is a coherent explaination for your rationale, ie what's a good rule of thumb outside of the extremes?

*****************

I start with my answer:

A will be stiffer when loaded from the top.
B will be stiffer when loaded from the side.

This the stiffness of a beam (with length and material constant) is goverened by its second moment of inertia (also called area). The second moment of inertia is a function of how much material there is and how far it is removed from the centre axis (numerically distance squared x area) . Since A and B have the same area, the only difference is how far it is removed from the centre axis. When A and B are loaded on the top surface, A's cross sectional area is more removed from the centre axis, thus it is stiffer. The same can be said for B when loaded from a side surface.

How does this apply to fullers when machined on a part? Suppose we cut out a fuller from the top and bottom of A resulting in such a cross section:

X__X
XXXX
XXXX
X``X

The above "rationale" leads to the following conclusion: the beam cannot be stiffer now that a), it cross sectional area has decreased, and b) most critically it has been removed from the area where it is most needed, ie the furthest away from the centre axis.

Moment of inertia:
http://www.cmilc.com/engineering/designtheorypages/inertia.htm

Amout of deflection, ie stiffness:
http://www.cmilc.com/engineering/designtheorypages/deflection.htm

And prehaps the skeptics can do some calculations outlined here and see if a hollow tube of the same diameter of ever stronger than solid rod, or a hollowed rectangle can be a strong as a solid rectangle of the same exterior dimensions:
http://www.atcpublications.com/Sample_pages_from_FDG.pdf

 

[Thomas Linton]

I'm sorry that you cannot distingush between having a structure designed around using I-beams of plywood and someone taking a gouge to their house's 2x4's to improve its strength, as fullers obvious do.

The I-beam of plywood is as little forged as an I-beam of steel. Both have a purpose to their shape.

 

[Thomas Linton]

Okay, let's try this: take beam A and B of the respective cross sections:

A......................B

XXXX
XXXX...........XXXXXXXX
XXXX...........XXXXXXXX
XXXX

They both have the same cross sectional area, 16 sq units.

Which beam will be stiffer when loaded from the top surface?
Which beam will be siffer when loaded from the side surface?

What is a coherent explaination for your rationale, ie what's a good rule of thumb outside of the extremes?

Beyond observing that shape, rather than mere mass, is revelant to performance of a structure, I fear I cannot understand either your question or it's relevance to a discussion of the purpose of a fuller. Perhaps another member here can assist.

Suppose we cut out a fuller from the top and bottom of A resulting in such a cross section:

X__X
XXXX
XXXX
X``X

The above "rationale" leads to the following conclusion: the beam cannot be stiffer now that a), it cross sectional area has decreased, b) most critically it has been removed from the area where it is most needed, ie the furthest away from the centre axis.

Apparently, the enginners are wrong to use I-beams, as are all those who have made fullered blades over the centuries. Also, I see problems with removing metal from the center of a blade and leaving it hollow because it may be subject to impacts.

If you were to note that the fullers in use may not, in every case, be engineered to achieve the best result possible, that could well be the case. Many fullers are decorative, or even weaken the structure, as in the case of the knife in question. But your insistance on denying the benefit possible from use of a fuller reminds me, with respect, of the lad who "proved" that a bee cannot psssibly fly.

 

[kel_aa]

Apparently, the enginners are wrong to use I-beams, as are all those who have made fullered blades over the centuries.

Who said they were wrong? It depends on that they are trying to achieve. If you want pure strength, you cannot do that by removing metal. If you want a better strength/weight ratio, you can redistribute the mass or eliminate some mass in certain ways. By the way, notice the are refered to as I-beams, not H-beams. I-beams resist bending when loaded on the top surface. Does a fuller on a blade resemble an H or an I when laid flat?

 

[Thomas Linton]

Who said they were wrong? It depends on that they are trying to achieve. If you want pure strength, you cannot do that by removing metal. If you want a better strength/weight ratio, you can redistribute the mass or eliminate some mass in certain ways. By the way, notice the are refered to as I-beams, not H-beams. I-beams resist bending when loaded on the top surface. Does a fuller on a blade resemble an H or an I when laid flat?

One assumes that the effect is to produce an enhanced ratio of weight to strength. If strength were the only consideration, one would simply add steel (or wood, in the case of wooden members) to whatever mass creates the level of resistance to bending desired. In the case of tools/weapons, weight is an obvious consideration.

As to your second inquiry, the blade is typically designed to resist inpact against its edge, so the fuller creates an I-beam, resulting in superior stiffness for the weight.

 

[kel_aa]

One assumes that the effect is to produce an enhanced ratio of weight to strength. If strength were the only consideration, one would simply add steel (or wood, in the case of wooden members) to whatever mass creates the level of resistance to bending desired. In the case of tools/weapons, weight is an obvious consideration.

I think it is usually described in terms of strength to weight ratio, which is trying to be increased. But but having a better ratio does not necessiate the strength being increased, as it can be accomplished by decreaseing the weight and decreasing the strength. 13/4 > 14/6, but 13 is not greater than 14. In the previous discussion, however, the such ratio was never mentioned. It was only stated that it would be stiffer, which is false.

As to your second inquiry, the blade is typically designed to resist inpact against its edge, so the fuller creates an I-beam, resulting in superior stiffness for the weight

The implication is that it is not designed to resist bending laterally? If you say so.

 

[BluesStringer]

Forgive me for the tardy reply. Been real busy and hadn't even looked in here for several days. Anyway.....

Ala. Code Sec, 13A-11-50: "Except as otherwise provided in this Code, a person who carries concealed about his person a . . . knife . . . shall, on conviction, be fined not less than $50.00 nor more than $500.00 and may also be imprisoned in the county jail or senetenced to hard labor for the county for not more than six months."

So Alabama law is, as to liability, worse than Ohio's, where one can at least argue that a knife is not a procribed "weapon" (but is. instead a tool), whereas Alabama expressly procribes concealed knives as such. (The typical defense of reasonable requirement for self-defense originally in the Common Law applies in both states.)

This would, of course, not apply to a knife carried openly, much less in a display case in Alabama. You have been quite clear that you have no intention to carry this item, but others might.

You wouldn't possibly be deliberately misleading just to win a point would you? The "....." in the law you quoted are honest in that it shows that you cut something out, but absolutely intellectually dishonest because you comment on it as though the missing text is irrelevent to your point. It isn't.

DIVISION 1. GENERAL PROVISIONS.
§ 13A-11-50. Carrying concealed
weapons.
Except as otherwise provided in this Code, a
person who carries concealed about his person a
bowie knife or knife or instrument of like kind or
description or a pistol or firearm of any other kind
or an air gun shall, on conviction, be fined not less
than $50.00 nor more than $500.00, and may also be
imprisoned in the county jail or sentenced to hard
labor for the county for not more than six months.

The bolded part is what you cut out. You don't think the word "bowie" is relevent to the point you're trying to make here? I do. The word specifically excludes folding knives for one thing, which just happens to be the subject of this thread. Secondly, the word makes it clear that the law is nowhere near as restrictive as the one you describe in Ohio, and contradicts your assertion that, "The point is that CCW is NOT "legal" anywhere unless the weapon is one where a CCP is provided by law and you got one." There's no provision for obtaining a permit for a knife at all in the whole section of the Alabama Code covering CC, knives, pistols etc., and only one type of knife is restricted in any way, shape, manner or form from being concealed.

Now, I suppose one could argue that the description of a "bowie" knife can mean just about anything one wants it to mean. Good thing that there's case law to turn to in that case:

Alabama Case Law:

- A "butcher's knife" 11 inches long overall is a knife "of
like kind or description" as a bowie knife (1897).
- "A 'bowie knife' ordinarily designates a long knife shaped
like a dagger, but having only one edge, and does not
include a knife which opens and shuts and is not too large
to be carried in a trouser's pocket..." (1985)
- "'Lock-blade'" knife not included... within the statutory
prohibition." (1985)

So there ya go. There's little ambiguity as to what the law means by "bowie" knife.

I don't know why you found it necessary to delete words that the law is actually putting restrictions on, but I do know for sure that NO CCP is needed for the knife in this thread, or any other folding knife, and that saying, "The point is that CCW is NOT "legal" anywhere unless the weapon is one where a CCP is provided by law and you got one." is a completely erroneous statement. I'd be real surprised to find out that it's not a vastly overstated assertion in MOST states, but it's definitely overstated for Alabama.

Blues

 

[Thomas Linton]

You are absolutely correct that Alabama courts have specifically held that the words "or knife or other instrument of like kind or description" modify "bowie knife" and are not to be read in the disjunctive. Apparently, this statute was enacted as a result of the panic over the extra deadliness of the "bowie knife," whatever that was thought to be. I would agree that the knife in question is not a "bowie knife."

We have all benefited from your fuller explaination.

(Ed: Nor do I think that the knives sold as "folding bowie knives" [e.g. www.worldknives.com/product.asp?produid=767 "Andujar" ] should, in fact, be called bowies. A "bowie" should at least be a fixed blade knife.)

 

[quinque voces]

Interesting discussion between kel_aa and Thomas Linton.

If you want pure strength, you cannot do that by removing metal. If you want a better strength/weight ratio, you can redistribute the mass or eliminate some mass in certain ways.

I guess this sums it up nicely.

With regard to Boker's Reality Based Blade and especially the U-shape of its blood groves I recall Boker stating on a German Knifeforum that they would have prefered omitting them. Designer Jim Wagner however insisted on them as well as on the mark near the tip of the blade which is meant to indicate the non-lethal range for stabbing. Boker wasn't too happy about both features but complied with Wagner's requests.

 

[darkestthicket]

Yes, yes you are completely wrong. They are there to add rigidity to the blade. See when you remove and area of the blade like a blood groove it makes the knife more rigid since there is less steel. Hope that makes sense.

What? Traditional blood grooves on katana are there to make a heavy blade lighter, for decoration, and as an opposite lessen the amount of flexx in the blade making it essentially easier to break rather than take a bend. They also add a different sound to a katana when swung, you can tell the difference in sound very easily... blood grooves do not have corners and do not wind around the same spot on the blade. Id almost buy one of these to test to see if that blade breaks exactly where that blood groove is...but i dont want to waste the cash.

The shape of the fullers here, as well as the fact that one of them runs across the blade rather than down its length, make these more decorative and disfunctional.

Exactly.

I beams do not have sharp corners in their angles.

Ditto.

Not to get too off the exciting topic of the "Boker Reality Based Folder."

Maybe I am missing your point. But, the fuller adds structural strength to the blade.

Not really, it also makes them more fragile if you screw up. no blood grooves = blade will take a set bend, blood grooves = blade will snap or shatter. ive broken 3 paul chen katana with blood groves. The one on the RBB is definetly decorational only.


Only my experience and please, no one take this as a slam.

 

[Pahtoocara]

ive broken 3 paul chen katana with blood groves.

Ok, that sounds cool.....I want to see pictures, please post.

I would say, however, fullers perform different functions in different kinds (designs) of swords. To say, matter of factly, a fuller weakens all swords may not be prudent.

The one on the RBB definitly decorational only.

This was stated before, however I think it was lost in the whole fuller discussion mess. My bad.

The fact remains...the description from the Boker website *claims* this knife has "two blood grooves in the blade." If they are "blood grooves" (if blood grooves do exist) do they really serve a functional purpose on this knife? My answer, nothing but aesthetics.

Maybe the poster who started this thread would volunteer to test out his knife?

 

[darkestthicket]

Ok, that sounds cool.....I want to see pictures, please post.

I would say, however, fullers perform different functions in different kinds (designs) of swords. To say, matter of factly, a fuller weakens all swords may not be prudent.

Pictures would be difficult as i havent had the 3 swords involved for more than 2 years (last one) and as long ago as 4 years, the swords involved were the Shinto w/ bo hi (fuller, bloodgroove, whatever you choose to call it) and 2 PC tigers w/bo hi and i wasnt the documentist that i am now. if i break my current Tiger Ill definetly take a pic. just a side note, i got a nice cut from the shinto. Edit : for the record i WAS doing silly cutting practice with the swords in question, 2x4 tamishigiri if i recal correctly. I do not reccomend that for any sword. I have broken or bent 5 swords this way (last one was on a 4x4)

sorry if i restated the obvious, i only stated what i thought.

secondly, you are correct in that i have no experience with other types of swords, only katana, I do believe the katana is the originator of the Bo Hi though isnt it? I have seen old kukri with them also however. no intentional disrespect of other blade types intended

anyone know what the originator of the bo hi/ fuller/ blood groove was?


edit the third to get back to post topic or at least close to it.

And just by chance you ever do need to use your knife for self defense or the defense of another, which would you like to hand over to the police as the first impression of who or what type of person you might be?

This ???

http://putfile.com/pic.php?pic=6/17617431690.jpg&s=f5

Or this ??

http://putfile.com/pic.php?pic=6/17617420327.jpg&s=f5

I would pick :
http://i108.photobucket.com/albums/n3/Darkestthicket/collection.jpg
the lil beauty in the center, using the triscula grind for its intended purpose and advising the Cop I had, and could point to wound marks showing the fact that i tried to de-escalate rather than just go stab happy for a kidney or something, a couple of terzoula scrapes on the arm should be enough to prove need of additional force as necesariy as my assailant had proven more than willing to stick around while i had only defended myself and more than likely proove that said assailant was more than willing to do more than triscula scratch level damage to me. (cant find appropriate word, scratch doesnt do it justice) I think odd looking self defense blades when used properly can actually help a self defense case. They shouldnt be maligned for their odd looks.

Folks, forgive me i may have had one to many while typing this. lol.

 

[Pahtoocara]

If you get a chance (and are interested) catch the new Black Belt mag article by Wagner ref his "Reality-Based Blade".