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Katana in 3V

Discussion in 'Sword Discussion' started by Richard338, Oct 23, 2018.

  1. Richard338

    Richard338 Gold Member Gold Member

    548
    May 3, 2005
    I've been slowly putting together a non-traditional katana in CPM 3V steel and posting many of the steps over in Shop Talk. This is my first attempt at a sword after making about 30-40 knives in various styles. Since it is just about finished I thought I would post a few pics of the completed project over here. (I still have a sageo cord on the way)

    The blade was made by stock removal from 3/16" thick 3V, heat treated by Peters to 60 hardness. I hand-filed a tsuba and made other fittings (seppa, fuchi and kashira) out of damascus.

    The core of the handle is terotuf, assembled with corby bolts and epoxy (can't be taken apart).
    I did a full covering with rayskin wrapped with silk ito over gold plated menuki.

    The cost of the parts alone is more than any "battle-ready" sword on ebay, but I learned a lot and have something that I won't be afraid to do some chopping with.

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  2. Joseph Gardner

    Joseph Gardner

    79
    Oct 12, 2018
    I like your work alot, perhaps the only critical flaw would be the lack of spinal taper from hilt to tip, traditionally the taper at the tsuba can be a third an inch wide. So this things balance and weight distribution will be horribly off. You also didnt give it brass collar rings at the tsuba and it doesnt come apart, these are the first of qualities an expert and bladesmith will observe in that they will want to examine the tang for inscription. However given the quality of the steel i tip my hat to you for crafting this. I especially like the tsuba.

    Have you done preformance tests yet?
     
  3. Richard338

    Richard338 Gold Member Gold Member

    548
    May 3, 2005
    Thanks for your comments. When designing I looked at a lot of measurements on this site: http://www.toyamaryu.org/SwordMeasurements.htm
    Some have more distal taper than others. Besides the distal taper in thickness, there can be tapering in height. Mine is 1.33" at its tallest and 0.9" at the yokote (near the tip). In addition to the balance obtained by that reduction, my convex grind resulted in a slight distal taper (admittedly not as much as you see on some). I do have a damascus seppa between the tsuba and the habaki. There are also damascus fuchi and kashira on the handle.
    I measured the balance point at 5" in front of the tsuba (about 4" in front of the habaki).
    I am still sharpening it, but will do some tests soon.
    It does feel very light and quick to me, but I haven't handled other swords of this type to compare.
     
    Mecha and JJHollowman like this.
  4. Joseph Gardner

    Joseph Gardner

    79
    Oct 12, 2018
    Im actually a sword smith and i hate the grind ever so, and the thought of grinding away that much 3v on stones gives me a headache, much less the thought of cleaning out fullers. Yuck.

    So how to explain this... A billet would be laminated in large thickness and then forged into a bar 18 inches long with 3/8ths thickness by 1 inch wide, with two tapers from 1 foot and 6 inches down to half an inch. It might weigh 3-4 pounds depending on the content. The mass is distrubuted now to form the balance. The bar then might get flattened down and stretched to .3 or even as thin as .2, and the blade section is beveled and spine stretched distally and longitally down to the spine at the tip to as thin as .1. Giving the blade length of 24-29 inches (historically reprosentative blades are never longer then this)

    The result is that there is ALOT of steel in the tang and despite weighing 3 or more pounds there is enough mass in the tang to put the balance point with fittings at right where you would grip it, sometimes an inch above or below depending on the smith.

    Despite being heavy all of the weight ends up in your palm and the leverage point pivots around your center of gravity.

    (I swing a 4lb hammer so i dont think anything of this weight)
     
  5. Joseph Gardner

    Joseph Gardner

    79
    Oct 12, 2018
    in short there is no need to add balancing factors because there should be enough steel in the tang to counter balance the blade naturally.
     
  6. Richard338

    Richard338 Gold Member Gold Member

    548
    May 3, 2005
    Yes, I understand that balance is very important in a practical sword.
    I knew going in, and especially for my first sword, that I wasn't carefully planning the balance.
    I looked at some threads about non-traditional choppers like the Keffeler super assassin also made in 3V.
    Those and others like it seem to be designed for pure chopping performance (tree limbs etc), with relatively short, thick, wide and straight blades.
    I decided to go for a lighter more traditional shape even if it means that I won't try chopping any ice blocks.
    As I said the balance point is about 5" in front of the tsuba.
    I haven't weighed the total package yet, but it feels pretty light to me.
    Since I only make blades for my own amusement, and never sell anything, no one will demand their money back...
     
  7. Richard338

    Richard338 Gold Member Gold Member

    548
    May 3, 2005
    I'm curious now about the balance point in a traditional katana.
    Since the habaki has to fit over the tang to get to its location, the tang has to be profiled similarly to the blade.
    This implies that one can't have a ton of mass in the tang...
     
    Mecha likes this.
  8. Joseph Gardner

    Joseph Gardner

    79
    Oct 12, 2018
    So the mass being predetermined at the triangle stage the dimensions do not matter since the metal is drawn away from the axis there are some where the tang is left at 5 inches and others where its drawn longer, drawing the angle does change not the mass since no material is gained and a small amount lost from forging.

    The application is that the blades pivot point is right at your hand allowing you to change the angle quickly, adding a second hand leverage wise actually doubles your power mechanically. The center of mass is kept attached to yours, you then litterally throw yourself in close ground and fling the blade away from your mass. The angle makes contact and should smoothly draw through the target maintaining edge contact all the way out the tip in a smooth start to finish, the tip should actually trail off accelerating through the cut. Because of the balancing as the blade draws it GAINS leverage and power as it draws.

    A proper longital taper will also wedge the edge further along the blade with drag giving you more cutting power, so quite litterally having a longital wedge on your spine is better then a strait one, not to mention the strictural advantages of the shape. You might not notice this effect on a small knife but on 24 inches of steel it really does matter.

    Having the balance higher up narrows your sweet spot, and it will give you a harder chop initially but you lose acceleration and suffer from drag more.

    Its a mechanical design really not an astetic one.
     
    Last edited: Oct 26, 2018
  9. madcap_magician

    madcap_magician Gold Member Gold Member

    Feb 27, 2005
    This is really cool work and is a really ambitious project for the level of experience you say you have. Fine craftsmanship and good planning! I'm curious about why the menuki is set so far forward the blade, though?
     
    palonej likes this.
  10. Joseph Gardner

    Joseph Gardner

    79
    Oct 12, 2018
    To answer your question though, the habaki is forged and welded right onto the blade.

    Walter sorrels runs a youtube channel called tips for the knife.maker but he also makes alot of okish katanas from w2. He has tutorials on how to make the habaki
     
  11. Richard338

    Richard338 Gold Member Gold Member

    548
    May 3, 2005
    Re menuki: I tried to follow info I found online. On the omote (front or showing side), it tends to start about three wraps in (closer to the tsuba) . Conversely on the ura (backside) it is about three wraps from the bottom.
    For a right handed person this matches where my hands want to grip.
    Re balance: I will look into this some more. I'm in the planning stages of a viking sword!
     
    JJHollowman and madcap_magician like this.
  12. Richard338

    Richard338 Gold Member Gold Member

    548
    May 3, 2005
    I'll check that out. The tutorials I followed had a removable habaki.
     
  13. Lapedog

    Lapedog Gold Member Gold Member

    Dec 7, 2016
    I think it is just beautiful.
     
  14. Lapedog

    Lapedog Gold Member Gold Member

    Dec 7, 2016
    Check out Yagyu anatomically correct menuki (gyakute menuki). They switch the placement for a right handed person so the one closer to the tsuba is on the back side and the one closer to the butt is on the front side. This way they sort of fill into the palm of your hand.

    It is considered by some to be a good idea and by some the equivilant of edo period mall ninjary.
     
    Mecha likes this.
  15. Joseph Gardner

    Joseph Gardner

    79
    Oct 12, 2018
    Habaki also had enough room for the collar rings and the tsuba, these act as shock buffers from the blade to to gaurd to the handle, but as well could be removed and replaced with thicker rings to tighten the fittings.
     
  16. Joseph Gardner

    Joseph Gardner

    79
    Oct 12, 2018
    Youre on the right track though keep making em.
     
    Last edited: Oct 26, 2018
    Richard338 likes this.
  17. horseclover

    horseclover Basic Member Basic Member

    Nov 21, 2000
    Otherwise known as seppa
     
  18. Joseph Gardner

    Joseph Gardner

    79
    Oct 12, 2018
    Well the tang profiles out normally on a forged ninhoto so when you do the forging of the habaki and weld it together on the blade it still slides down. The hot metal will form enough oxide on the blade to prevent it from welding to the blade itself
     
  19. Richard338

    Richard338 Gold Member Gold Member

    548
    May 3, 2005
    You mentioned being a sword smith. What styles do you make? Do you work by yourself?
     
  20. Richard338

    Richard338 Gold Member Gold Member

    548
    May 3, 2005
    I have been thinking about how I would alter my designs to shift the balance point.
    However, the more info I dig up, the more I'm confused by your comments about the balance point.
    I'm finding source after source after source that place the balance point 3-5" in front of the tsuba.
    People who describe handling old katanas mention 3-5 inches. Modern swords like Paul Chen list 5".
    You mentioned Walter Sorrells. I found a youtube video of someone taking one of his swords apart.

    At 5:28 and beyond in that video, you will see that his tang narrows and carries the same profile as the blade.
    His habaki is not welded on as you described, but slides easily off.
    His tang clearly doesn't have the kind of mass you are talking about.
    All of the old Japanese blades I can find images of can be disassembled to a bare blade and have tangs with similar appearance.

    My sword is 2 lbs 6 oz with a balance point 5" in from of the tsuba.
    From what I'm finding, both of these parameters are pretty typical.
    I would be interested to hear others weigh in on this balance point question.
     

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