Oppinion on fancy "three-handed" sword?

This is just stresses typical of use. As far as the heat-treatment goes, I have to admit I'm a little concerned myself. One possible solution would be to clay-coat the "innards" to prevent excessive quenching and heatshock. Another would be to use an induction-heater or a gas-torch setup to only harden the edge-side. The main problem is the heatshock "inside" the slots as I see it, not the slots per say. I need to see if I can find some sort of software to simulate this, but I suspect that as long as you cover the slots up entirely, you won't have nearly as much problems.
 
That looks pretty similar to what I'm trying to do. But with the wider blade-portion and oddly shaped cutouts, his design is if anything MORE susceptible to heat-shock. I'm starting to feel more confident about heat-treating it now! As soon as I get hold of a descent stock-metal, I will start up the plasma-cutter and grind me a prototype.
 
Here's a little update;

Okay, so I am screwed in regards to getting hold of any decent stock-material. Living in the northern arse of Sweden has it's disadvantages. None of the local shops or industries use high-carbon steel in the right thicknesses. I think I've found a solution without having to pay through my nose for shipping though; Make it yourself. I'm goring to carburize some regular mild-steel.

I have access to a large wood-furnace (300 liter capacity of 1.2 Meter long wood) that I found can reach critical temperature easily during normal operation, and hold it for several hours. If this works I won't even have to make or rent time at a forge. I'm going to make a test-run first of the whole process though; I've made a dagger version of the sword with all the relevant features included and with the rough edge and taper finished. It also served as a useful ergonomic-test after which I changed a few proportions on the final design. There are no slots or fuller on this blade; The plan is that I will make those after the carburizing to prevent excess brittleness and potential cracking. This goes for both the dagger prototype and the sword. Naturally, I will be testing the heat-treating on the dagger first as well.

Here's the dagger version:

cbAXKNP.jpg


What struck me was just how heavy the thing is without the fuller and slots. 780 grams for a blade only 36 cm long! According to estimates from the sword CAD-file, I will be able to cut that down to around 450-500 grams once I'm done.
 
How much longer are you going to avoid the inevitable: TITANIUM THREE-HANDLED SWORD! I mean, Russia is like right there, and they are flush with the stuff!
 
Get in contact with Aldo at NJSB, and get some real steel shipped to you.
 
Reasonable is in the mind of the beholder. International shipping is often cheaper than Canada/USA shipping in my experience, unless Sweden has some strange tax or duty.
 
Fancy Karl said:
For those concerned about stress-raisers and sideways stiffness... Stress concentration in holes (or cracks) is proportional to square root of the hole diameter. With 10mm minimum radius, the cutouts provide very minor stress-increases, as compared to sub mm cracks. As for sideways stiffness, there are two uninterrupted bands at either side of the fuller with full "stock" thickness of 10mm. This tapers down to 5mm towards the point. It's all verified by both regular mechanical equations (in regards to stress-raisers) and FEM-analysis. Unless you shear through the edge or spine of the blade, which is a 8mm x 6mm square-section at the thinnest point, it's not going to break.
Click to expand...

Too me it looks too stiff. A sword is supposed to be light and flexible to survive repeated shocks. This looks about as durable as a shard of glass.

n2s
 
It did occur to me to name it "Lucifer's ice-skate"...

On the more serious note, I have all the materials needed for pack-carburization here at home, for free. If nothing else, it will be an interesting experiment. The prices for good steel and shipping are still way too high for my broke-ass budget.

Going for an extremely stiff blade was sort of the point, to maximize chopping-power. I know it stresses the material more, but according to calculations and simulations it will do so evenly throughout the blade. I'll be sure to put it through it's paces once I'm done and post the results.
 
Another update; I've given up on the carburizing. The wood furnace I planned to be using is only operational during winter. And I'm not waiting. Instead I might have found a better alternative.
I've gotten hold of some road-grader blades that are supposed to be tough and hold an edge really well. Without the worries of uneven carbon-diffusion, grain growth and uncertain carbon-content of home-carburized steel. So I guess my question is; DOes anyone have any experience with these grader-blades? Aside form being a pain in the ass to machine, it seems like really good steel for a large and heavy sword.
 
From what I've read, it depends on age. Older ones might be a 1050 series steel with added manganese for abrasion resistance while the newer ones might be a 1030 or 1020 series steel with added boron and manganese for hardness and toughness. But I don't have any hands on experience. Probably better for impact tools like a hammer. But, for your trench knife (doesn't look like a sword) it could be ideal. It probably won't hold an edge very well though.

Ooops, missed the dagger comment on your picture.
 
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I'm ready to see the damn three-handled sword!
 
Maybe Fancy Carl will resurface now that it's freezing cold in Sweden again.
 
Nifty project and the dagger is pretty cool too. Nice to see something "outside the box". :thumbup::cool:
 
I'm interested to see how the design performs, even in a mild steel prototype, just seeing how the weight and point of balance act together. As an image it's striking, but looks unwieldy, then again you never know. Bring on the sword!
 
I'm not gonna argue against this, all I have to say is if this does go into production PLEASE let me know and I will gladly buy one.
 
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