Fusion Battle Mistress - Distress

JohnTheTexican said:
Yeah, you need a drink too. The fluted barrel is stiffer than a thinner barrel of similiar weight. It is not stiffer than a non-fluted barrel of equal diameter. the non-fluted barrel of the same diameter is stiffer. But it is less stiff than a non-fluted barrel of the same diameter. It is less stiff because metal has been removed. But it will be stiffer than a non-fluted barrel of the same weight but of a lesser diameter.
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Glad you posted John...you're right on the money.

Bending stiffness is proportional to E*I (modulus of elasticity*cross sectional moment of inertia). The E is the same for both barrels so it cancels out. Calculated the I for a fluted and non-fluted barrel *of equal diameter* and you will see that the moment of inertia is less in the fluted barrel. It has to be. Has nothing to do with the angles if the flutes. The cross-sectional area of the fluted barrel is simply less no matter what the geometry of the flutes.
 
Jerry Busse said:
Okay John, I'm diving into this because Johnny Walker told me to. . . . !!!:eek:

Take a look at a piece of 12" wide by 48" long, thin sheet metal. . . in general it is very flexible and bends under its own weight. . . Now take a look at a similar sized piece of corrugated sheet metal of the same thickness and outside dimensions and you now have greatly increased strength and rigidity which makes it nearly impossible to bend. You also have a greatly increased amount of actual surface area in the same amount of space. . . .Does this make sense?. . . . If not, then one of us needs to drink more. . . Okay, I volunteer!!!!:D :thumbup:
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Wrong. Take you're 12" wide flat plate. It measures 12" wide end to end because it is flat.

Now take you're corrugated plate that's 12" wide end to end. If instead of measuring end to end, you measure following the grooves and countours, you'll see that it total length is MORE than 12" Therefore it's cross sectional area is greater and it is stiffer because you've added material.

It does increase surface area but *not* in the same amount of space. The volume is increased.

If your basing your claim that beveling a blade makes it stronger on the above posted logic, I'm worried.
 
are the grooves there because steel was physically removed or are the grooves there because the steel has been compressed?
 
rtiger2 said:
Wrong. Take you're 12" wide flat plate. It measures 12" wide end to end because it is flat.

Now take you're corrugated plate that's 12" wide end to end. If instead of measuring end to end, you measure following the grooves and countours, you'll see that it total length is MORE than 12" Therefore it's cross sectional area is greater and it is stiffer because you've added material.

It does increase surface area but *not* in the same amount of space. The volume is increased.

If your basing your claim that beveling a blade makes it stronger on the above posted logic, I'm worried.
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Worry not my friend. . . The corrugated bevels on the Fusion Battle Mistress are convex as opposed to flat, like they are with ground bevels. There is much more cross-sectional mass with a convex corrugated bevel than there is with a flat ground bevel of the same height. If we were corrugating flat bevels of the same geometry as our ground blades then you would have reason to worry.

As for your argument where you state, ". . . you'll see that it total length is MORE than 12" Therefore it's cross sectional area is greater and it is stiffer because you've added material." I have to disagree. It is not stiffer because you have simply added more material. Let's say that your total width is now 14" after the corrugated bevels were flattened out. This 14" wide piece would be MUCH weaker and much less stiff than if it were still corrugated and only 12" wide. Heck, a 14" wide piece of flat sheet metal is no where near as rigid as a MUCH narrower and lighter 6" wide corrugated piece of the same length. . . .

Time to drink! :thumbup:

Jerry
 
As an engineer I must say Mr. Busse knows his Kung-Fu pretty well.


Hog-Fu!
 
Jerry Busse said:
Worry not my friend. . . The corrugated bevels on the Fusion Battle Mistress are convex as opposed to flat, like they are with ground bevels. There is much more cross-sectional mass with a convex corrugated bevel than there is with a flat ground bevel of the same height. If we were corrugating flat bevels of the same geometry as our ground blades then you would have reason to worry.
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Great! I'm glad to hear that they are convex. But then this begs the question, why not leave it with a full height convex grind where the convex height is the same as the bevel peaks? This would be stiffer yet.

As for your argument where you state, ". . . you'll see that it total length is MORE than 12" Therefore it's cross sectional area is greater and it is stiffer because you've added material." I have to disagree. It is not stiffer because you have simply added more material. Let's say that your total width is now 14" after the corrugated bevels were flattened out. This 14" wide piece would be MUCH weaker and much less stiff than if it were still corrugated and only 12" wide.
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Point taken. I should have been more exact. The increase in stiffness is more than just the increase of cross section; there are actually two components to it. The stiffness is actually proprtional to the integral of x^2*dA, where dA is a differential area at distance x from the neutral axis. The corrugated sheet does have more material (the dA part) and the corrugations move the material a greater distance off the neutral axis (the x^2 part) than for a flat sheet.

By flattening the sheet out, the area remains the same but the distance of that material from the neutral axis is reduced. This reduces the x^2 term and thus the sheet gets wimpier as you observe.

And who said solid mechanics can't be fun?
 
rtiger2 said:
As an engineer I must say that remains to be seen. I haven't tested the FBM yet.:)
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I'm pretty sure we are all going to have some fun testing!
 
Jerry Busse said:
Worry not my friend. . . The corrugated bevels on the Fusion Battle Mistress are convex as opposed to flat, like they are with ground bevels. There is much more cross-sectional mass with a convex corrugated bevel than there is with a flat ground bevel of the same height. If we were corrugating flat bevels of the same geometry as our ground blades then you would have reason to worry.

As for your argument where you state, ". . . you'll see that it total length is MORE than 12" Therefore it's cross sectional area is greater and it is stiffer because you've added material." I have to disagree. It is not stiffer because you have simply added more material. Let's say that your total width is now 14" after the corrugated bevels were flattened out. This 14" wide piece would be MUCH weaker and much less stiff than if it were still corrugated and only 12" wide. Heck, a 14" wide piece of flat sheet metal is no where near as rigid as a MUCH narrower and lighter 6" wide corrugated piece of the same length. . . .

Time to drink! :thumbup:

Jerry
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The Reason why Jerry is correct about stiffness with corrugations is for the same reason that a 1/4 inch thick piece of flat stock will not be as rigid as that same 1/4 inch thick flat stock with welded with 1/2 inch wide metal pieces on each end. The I-beam theory like Skunk so eloquently put it.. The cross sectional area is much larger for the same thickness making it stiffer. You have to calculate the equivalent rigidity component that the ridges add to make a blade thick enough to equal it's stiffness. I would guess that it would take 10% more thckness to equal the stiffness of the corrugated blade. But who really knows. You would have to test the flex.

Same holds true for the Heavy Heart whcih is a high sabre grind. The extra stiffness component adds to the equivalent thickness of the knife compared to full flat grind.
 
Cobalt said:
The Reason why Jerry is correct about stiffness with corrugations is for the same reason that a 1/4 inch thick piece of flat stock will not be as rigid as that same 1/4 inch thick flat stock with welded with 1/2 inch wide metal pieces on each end. The I-beam theory like Skunk so eloquently put it.. The cross sectional area is much larger for the same thickness making it stiffer. You have to calculate the equivalent rigidity component that the ridges add to make a blade thick enough to equal it's stiffness. I would guess that it would take 10% more thckness to equal the stiffness of the corrugated blade. But who really knows. You would have to test the flex.

Same holds true for the Heavy Heart whcih is a high sabre grind. The extra stiffness component adds to the equivalent thickness of the knife compared to full flat grind.
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HOLY CRAP!!! Someone hacked into Cobalt's account :eek: :p :D
 
Since we are getting technical here (we're going to start hitting the booze harder)

Will the effect of the corrugated bevels be more apparent/beneficial on a big blade like the FBM or even the AK47 versus a smaller blade like the Hell Razor?

Do the corrugations remain the same (profile height, space between bevels etc...) on the CNC program or each knife has a specific profile of corrugations.

If this innovation improves blade performance even 10% (hell even just preventing/minimizing the knife from binding on soft material like wood etc...) I must applaud BCI and it's creative team as a company of continuous innovation. Every time a new generation is introduced more and more features are added, that is not easy.
 
I'm glad I'm going into electrical engineering. Not too much conflict there -- it either works or it doesn't. But watching the ME's (mechanical engineers) debate physics is one of our favorite past times. :D
 
Whether it makes a busse stronger or not, just remember these fine words...

Whatever broke your Busse, killed you 5 mins earlier!
 
Who cares about the strength? It kills the satin finish, thus it is to be shunned.
 
How many engineers are in this thread?

Are we attracted to Busse knives because we are engineers? :confused:
 
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