Composite Blade Sword II

TankEpidemic said:
European swords at the time depended on brute strength and weight to force their dull blades through objects.
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I'm not sure why this falsehood is continually perpetuated. There is a vast array of readily available literature on this subject. Having said that, I'm intrigued by your laminated blades and hope that you continue to share what you learn as you progress.
 
Shawn you're right. That isn't always the case with those kinds of swords, I should have been more specific or have just chosen to use a different explanation all together. I was a bit rushed to get my point across and I didn't think about it, and for that I apologize. I hope you do indeed stay with us to see the progress! :)
 
David I completely agree with you that the 2 by 4 is not the intended target type for this sword. I suggest them in this instance as a test of the blade integrity, and because they are fairly standard items.

Tatami are too expensive Rolf! Also from what I have read, ridiculously easy to cut even with blunts. They probably will tell you about how well your geometry works in deep cuts especially on such a light blade.

Oh here's a good test medium... rope. Find someone who works near ships and get some used 3" or 4" rope. A 3 " rope has the cross section area of 9 pieces of 1" rope. Free hanging cuts will dynamically load the blade and let you test edge geometry. I need some mass to get through a 3" usually.
 
Great thread.
Thank you William. I know Hartsfield liked to use rope to teat his blades.
Rolf
 
David Stifle said:
You are making a light, fast blade who's primary application is cutting flesh.
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Lycosa said:
Or use traditional Japanese test cutting methods. tameshigiri.
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The Japanese also tested their swords on prisoners. I remember reading an exchange between a Samurai and a prisoner (sorry, I don't remember the book title/author - maybe Hank Reinhardt?) where the prisoner is approached by the Samurai. The prisoner asks if he is going to be used for sword testing and the Samurai answers in the affirmative. The prisoner replies that it is a very inhumane thing to do and if he had known he was going to face such an end he would have swallowed rocks to ruin the Samurai's beautiful sword. That story has always stuck with me . . .

As David stated, if you're making a light and fast sword, there is but one true purpose. We all test our edges and the different methods (ie paper, rope, wood, the brass rod test, etc.) have their place, but nothing beats real world testing using the blade's intended application. If you're making a fillet knife you need to cut some fish. If you're making a chopper you need to cut some wood. If you're making a sword . . . well you get the idea. :)
 
TankEpidemic said:
Well I've acquired the idea from katanas. People from japan at that time couldn't all wield large swords, so they made a weapon that relied on speed. European swords at the time depended on brute strength and weight to force their dull blades through objects. After a bit of thinking, I realize the sword we presented here is not a very suitable candidate to try and prove a point. We were trying to make an already light sword even lighter. I also understand that their are many other variables that gives the katana it's reputation as a good cutting tool (such as blade vibration frequencies, material used to make it, shape of tool, etc), but through my research and best of my knowledge, I've been told over and over that the katana was made to be lighter, and sharper, thus relying on speed and it's sharp edge to cut. It was made to suit the people in that area to their abilities. It may not be superior but it gets the job done in a different way and that is what we are trying to do with our design. We may post another thread with a different weapon model. Maybe a much larger sword that is more dependent on it's weight and strength. I would however like to thank you Lorien. Even if I am not right about my theory I very much appreciate your input. It is driving us to produce a better weapon or to learn something new about blades. Cheers. :)
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You have an interesting idea, but remember swords are not just bigger knives. If you really want to make swords reach out to people who really know about and use swords. Your statements about katanas vs. European swords are just wrong in about every aspect. (Think about it -- a sword that requires two hands to use is not a light sword.) There are other forums focused only on swords, there are groups that practice sword fighting, there is another part of bladeforums about swords.

You should be able to find plenty of youtube videos of people testing swords. If you haven't cut with a katana before, start with easy things: pool noodles, plastic bottles filled with water. Cutting these will give you practice in doing a straight cut. If you are twisting or not cutting straight you'll be putting a huge strain on your sword. If you can cut a bottle in half without knocking the bottle off the stand you're doing OK. Once your cutting is OK, you can try beach mats (tatami substitute) or other things... Look up Lance Chan on youtube. He shows practice cuts on hams etc.

One other idea. If you're focused on making a light, quick cutting sword, maybe look at some of the European sword types. Especially if you can make a sharp point. Think spadroon. You could make a very interesting swordcane. (Just as long as you're not in California, they are illegal to make or own here. :mad:)

Oops - just noticed you are in CA, forget the swordcane.
 
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Gator, I think you may be right about my knowledge on swords. Maybe a bit of what I know (perhaps all) is from a biased source. I am going to review all I know on this subject and try to get some information from other sources. Also, what type of sword shape do you recommend? We need more shapes to experiment with and to learn from, and thank you very much from your input, and input given to help us better our knowledge and skill is greatly appreciated. :)
 
I'd also like to say is that I have never had a greater time on any other forum. Everybody I've ever met on this forum has been extremely friendly and it even catches me off guard. Anywhere else on the internet I have to get info right or I would be eaten alive by replies telling me how much of an idiot I am and how worthless I am. I have not seen a single hint of intent to do that here. Everybody that has responded to anything I've posted has been extremely helpful and encouraging. I also realize I may have been posting these swords in the wrong section (duh) and I haven't had anyone complain about it. On other forums I would have been badgered by people telling me I'm an idiot for posting in the wrong section, or the post might have just been deleted altogether. I might have even been banned from the forum if this was a different site. I love this forum very much, it seems to just be perfect. It is run correctly as far as I can tell, everybody is friendly and insightful, everything about this forum grabs my attention in a positive way and I can't thank you guys enough for all your constructive criticism, insight and encouragement. Like I said, I like how this forum functions and I love the people in it. I thank you all from the bottom of my heart. Cheers. :)
 
Hey both our next door neighbors love bamboo and they gave us some to cut. This bamboo is 1 1/4" thick.
[video=facebook;559786700720453]http://www.facebook.com/video/video.php?v=559786700720453[/video]

Edit: wow the video's quality went straight down the drain. It is WAY better than this, it was crystal clear. Sorry for the bad quality, I'll try to fix it later and find a more suitable replacement.
 
Some thoughts:
Have you considered speaking with 3M about the type of loads the epoxy will handle? I know it says that it "won't fail" but that is undoubtedly a contextual claim. With a sword, you're greatly increasing the shock force applied to the cutting portion of the blade. I have no doubts about the toughness of the epoxy, but subjecting a lateral bond to concentrated shock forces on edge sounds like a recipe for failure against hard materials (bone).
Also, I have to agree with Lorien about the theory of a lighter blade. We all know that F=ma, and in practice this will produce a point of diminishing returns faster than you might think, where all of a sudden your increased speed just won't make up for the decreased mass. Consider the velocity of a strike. How fast can you swing a given sword? How fast can you swing your empty hand? Once you reach the point where your empty handed swing isn't much faster, you'll be seeing far less effectiveness for losing sword weight.
Another thing to look at might be the gradient of shock absorption and flex capability from a katana's edge to it's spine. The key to the indestructibility of this sword likely lies in it's ability to distribute shock forces well. Perhaps different types of bonds or fiber orientations should be used in different areas of the blade?

All that said, this is really cool. I'm excited to see where this goes and really impressed by the progress thus far! :thumbup:
and +1 to cutting bamboo and making videos of it!

EDIT: Oh, you just posted a video, but it isn't working. I think you might need to adjust your privacy settings.
 
Thank you so much for explaining what Lorien was saying, I thought I understood and I was wrong. I see what he's really saying now. I have been thinking about that sort of thing lately and the camp chopper we made has, I believe a 4" wide blade? It is a little more weighty and seems to work a lot better than the katana. I believe it sits right in the equilibrium of blade velocity and sharpness vs. blade weight and speed. It's light for it's size, but it has the perfect amount of weight to provide sufficient momentum to help the blade move through material. We have ultimately decided to move away from katanas and explore other blade this sort of construction could better. Thank you for letting me know about the privacy setting too, totally forgot about that. Also the only problem we have run into so far with the epoxy is that if we alter the carbon in any way (it is pressed with a pattern on the surface to help epoxy bond to it) it WILL split form the blade material.
 
Ask questions, experiment, improve and pretty soon you'll be the expert. :)

For a light sharp sword, I'd be looking at European swords from the 18th century and later. Firearms had made armor obsolete. Rapiers, sideswords, spadroons. All need a light, stiff blade with a sharp edge. Cut and thrust.
 
I think a good appication for the type of blade you are working towards would be tactical folders, but who know's? It would take a lot of work and testing. However, making a small blade and testing it would be a lot easier than making a sword. Just a thought.
 
I forgot to post this picture up a day or so ago. We have a stump that we like to throw things at in our back yard and we swung the sword at it.

tumblr_mj3hx5MNk21s4msb4o1_1280.jpg
 
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