Cbt = wtf?

Last Visible Canary said:
the stock satin jack takes 400lbs of force to get it to start bending, and takes a set at 900lbs. The corrugated satin jack takes 500lbs of force to bend, and 850lbs of force to take a set.

Its not stronger, it's actually weaker at the extreme end - but it's "stiffer". it takes more force to make it bend, but not more to make it fail.
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Why wouldn't it just bend in the thinner area between the milled grooves? They are thinner than the full thickness blade was, thus taking less force.

What it we take this example to an extreme, and mill the areas between the corrugations to 0.003 thickness? Would it be stiffer still?If removing a little material makes it a little stiffer then why doesn't removing more make it more stiff?

If you argue that taking it to the extreme isn't valid then don't you have to argue that there's some sort of 'break even' point where it stops getting stiffer and starts getting weaker? How would that happen?
 
leatherman said:
You just answered your own question right there "Its stiffer than a skinny barrel of the same weight"

When Jerry introduced the CBT technology he used the cardboard analogy. Corrugated cardboard is stiffer than flat cardboard of the same weight. With CBT's you get a stronger lighter blade than its non CBT cousin.

A side effect of the CBT's is a smaller contact area so the blade will not get stuck in the material as easily. When I baton hard wood this effect is dramatic, my non CBT chopper gets stuck very easily, my Fusion Battle Mistress hasn't been stuck yet.
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I like the smaller contact area reasoning much more than the cardboard example. That makes a lot of sense to me. A corrugated blade should have less contact area and therefore be less likely to get wedged in a cut.

Corrugated cardboard is indeed stronger than flat cardboard of the same WEIGHT, but it certainly wouldn't be stronger than flat cardboard of the same THICKNESS. A corrugated knife blade should be stronger than a thinner blade of the same weight, but it wouldn't be a strong as one that is the same max. thickness overall. Wouldn't 1/8" non-corrugated cardboard be almost like pegboard in strength?

Or, I could just be completely wrong...
 
elkins45 said:
Why wouldn't it just bend in the thinner area between the milled grooves? They are thinner than the full thickness blade was, thus taking less force.

What it we take this example to an extreme, and mill the areas between the corrugations to 0.003 thickness? Would it be stiffer still?If removing a little material makes it a little stiffer then why doesn't removing more make it more stiff?

If you argue that taking it to the extreme isn't valid then don't you have to argue that there's some sort of 'break even' point where it stops getting stiffer and starts getting weaker? How would that happen?
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as far as why horizontal fluting stiffens the blade against lateral bending -

Cpl Punishment said:
Reason is, they change the directions of the force vectors going through the material. So, say lateral force is applied, on a standard blade, the force vectors are all aligned. With the CBTs, particularly those on the CGFBM, will change the directions of the force vectors as they cross the CBT, basically enabling the metal to take the force in many directions instead of all in a single direction.
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There is a curve involved where the more material you take from a object, the weaker it will be come regardless of the construct. an I-beam is stiffened because of it's I shape, but the thickness of the material is specifically chosen/calculated for each application based on the forces that will be applied to it. If you want something that withstands more force you'll need a thicker stock or a stronger structural design/geometry.

if you reduce the cbt troughs down to .003" the knife would be completely unable to dissipate the force applied to it, the metal would bend in on itself, edge to spine. while you make the knife stiffer in one direction, you lessen it's ability to withstand bending force in the opposite (90°) direction.

I know you don't like the cardboard analogy, but it's like putting bends in cardboard when making a box, it's easy to bend it along the ridges, but very hard to get a straight bend when going at it 90°.
 
Corrugated cardboard in a tube makes equivocal calculaions between gun-barrel fluting and knife uh - face fluting? Bessel functions can be applied to both (i first wrote "flunctions canbe ap lied to death" -- a good sighn(anotherunintentional pun) that i need to lay off the undergrad physics and go cack to enjoying the way knifes work.
 
They also giv a good grip when you want to choke up on the blade.

100_0098.jpg
 
leatherman said:
You just answered your own question right there "Its stiffer than a skinny barrel of the same weight"

When Jerry introduced the CBT technology he used the cardboard analogy. Corrugated cardboard is stiffer than flat cardboard of the same weight. With CBT's you get a stronger lighter blade than its non CBT cousin.

A side effect of the CBT's is a smaller contact area so the blade will not get stuck in the material as easily. When I baton hard wood this effect is dramatic, my non CBT chopper gets stuck very easily, my Fusion Battle Mistress hasn't been stuck yet.
Click to expand...

i am with you ,man.
 
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