Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 22, 2010 0:42:38 GMT
If this has been brought up before I apologize. It's just something that has been on my mind as of late...
Even though I can't emphasize enough how important it is, something that is often not discussed is the edge geometry on blades. Among most sword enthusiasts, the question is rarely raised at all. Having a blade sharp enough to slice water bottles is heralded with applause. That's fine and dandy for backyard cutters and I admit it is satisfying and fun...
But what about those of us who are trying to get as close to genuine swords as possible? What about the old swords that were expected to encounter more than just soft flesh and live to tell the tale?
John Clements at ARMA has lectured us on receiving strikes on the flat of the blade. However, he didn't mention that to leave the edge unmarked, the oblique angles are only possible with blades of proper geometry.
A proper appleseed or clamshell backed cutting edge not only strengthens the edge, but waaay more importantly it actually drastically reduces the possible range of angles where edge to edge contact could happen at all. One can parry at a fairly steep angle with no edge contact. With a flat ground edge, you must go out of your way, curl wrist (which breaks structure) to parry cleanly and perfectly on the flat. Also of note is that I believe that nearly all parries are actually done at oblique angles. Perfect flat to edge would involve turning wrist unnaturally.
Thus, one could conclude that edge trauma on antique clamshell blades is the result of poor technique, fighting someone inexperienced, or having someone with a flat ground edge parrying you. Direct edge on edge between two blades with clamshell geometry is not possible with proper execution.
I would go so far as to say that flat ground edges are not even remotely suitable for repeated combat. Merely the act of crossing swords virtually guarantees that edge trauma will occur.
|
|
|
Post by randomnobody on Feb 22, 2010 1:11:29 GMT
An interesting note worthy of deliberation. Unfortunately, the only thought I can offer on the matter is that not ALL swords had that same convex edge. There was hollow ground, which to put simply is the exact opposite of the apple seed, and some blades were quite likely very much flat.
Swords underwent a lot of evolution, and it does seem the final take was a convex edge, but before then a great many other methods enjoyed popularity, as well.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 22, 2010 4:45:21 GMT
it all depends on what the sword was used for and the period... there's many swords that were used against chainmail and such and they all have apple-seed geometry, because otherwise the sword would be blunted after a few rounds with chainmail and/or shields and other swords. Others were hollow ground, to make them sharper, and my guess is that they were used in non-armored combat... Another thing that makes it clear why there are so many chiped, etc, swords is that they were not good quality... way back when, hey didn't have computers and such, so you couldn't tell the HRC hardness and other such things, so quality was variant... granted, someone who's been spending their lives making swords could see when something went wrong, but he would be glad (I believe) to sell it to the local peasant, for a much reduced prize. Add that to the fact that the peasant had no clue how to use a sword and there you have a sword that's chipped like it's made out of bronze
|
|
|
Post by Brendan Olszowy on Feb 22, 2010 8:07:33 GMT
I think you'll find that hollow ground swords stilll have the apple seed edge, for the first few mm. Only once it moves in and has developed some 'niku' does it go hollow as it approaches the spine. It was all about having the pronounced spine as a way of reinforcing the blade geometry to make it stiffer - for armour - not about making the edge geometry paper thin. So really the cross section of each bevel would be a kind of S shape.
Seems to me a common misunderstanding round these parts. And if it were hollow right to the edge it would be paperthin. And wouldn't spread a target for good cuts, and would be weak as ____. I think Garrett is on the right track.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 22, 2010 8:32:06 GMT
I think you'll find that hollow ground swords stilll have the apple seed edge, for the first few mm. Only once it moves in and has developed some 'niku' does it go hollow as it approaches the spine. It was all about having the pronounced spine as a way of reinforcing the blade geometry to make it stiffer - for armour - not about making the edge geometry paper thin. So really the cross section of each bevel would be a kind of S shape. Seems to me a common misunderstanding round these parts. And if it were hollow right to the edge it would be paperthin. And wouldn't spread a target for good cuts, and would be weak as ____. I think Garrett is on the right track. Thank you! I've tried to explain this a few times in different areas, but I was never able to word it as clearly as you just did. A hollow-ground sword is not like a hollow-ground knife. It doesn't refer to the edge, it refers to the contours of the blade flats. The edge is the same as any other comparable sword. I love the idea of the proper apple-seed edge reducing edge-to-edge contact. Makes sense to me, though of the articles I've read at ARMA it seems like "blocking" parries were rarely used anyway with cutting swords. You parry with your shield or avoid the blow as often as possible, and only contact blades to deflect an attack off course. It's more reliable and simpler and effective, better for your sword and worse for your opponent.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 22, 2010 8:47:55 GMT
Thanks for that Garrett! The importance of the apple-seed edge to "parry survivability" (for want of a better term) isn't something that I'd thought about until the thread on it in the 'Chinese Swords' subforum. I think it makes a great deal of sense! An important contribution to our understanding of swordsmanship, I'd say. Worthy of a karma, at least... Cheers Marc E
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 22, 2010 9:22:01 GMT
A hollow-ground sword is not like a hollow-ground knife. It doesn't refer to the edge, it refers to the contours of the blade flats. The edge is the same as any other comparable sword. I love the idea of the proper apple-seed edge reducing edge-to-edge contact. Makes sense to me, though of the articles I've read at ARMA it seems like "blocking" parries were rarely used anyway with cutting swords. You parry with your shield or avoid the blow as often as possible, and only contact blades to deflect an attack off course. It's more reliable and simpler and effective, better for your sword and worse for your opponent. Brendan and lunaman caught my drift. I'm talking about the small strip that backs the actual cutting edge. Not the contours of the blade flats. See the attached photo of oblique angle contact. In this photo I stopped just before I could feel edge grating. As you can see the angle is fairly steep and it would be difficult to suffer a damaged edge unless it was literally edge to edge. A flat ground cutting edge would not be able to pull this off. Ideally your blade doesn't touch anything until the finishing stroke, but that is up to the swordsman. As for the sword makers, an appleseed should be present on all cutting edges regardless. I believe this to be a universal truth. Attachments:
|
|
|
Post by randomnobody on Feb 22, 2010 20:02:59 GMT
Admittedly my knowledge of hollow-ground pieces come from the modern spectrum so perhaps my idea of the style is a bit skewed. All according pieces I have seen and handled terminated with a secondary bevel so I was unaware that convex bevels were the common way. I had always thought that a more wedge-like edge, in the form of the same "flat edge" discussed previously, was the method used more often.
The photo shown certainly doesn't look far away from destroying both edges, particularly of the blade on top. I am having difficulty determining the geometry of each edge, though, one being cast in shadow and the other reflecting the first blade a little to sharply for my poor vision.
Granted, going by the shadows and reflection, it does seem both feature a convex profile. Nevertheless, I can see how force of impact might "tilt" the edges into each other in a bad way from that angle... I suppose this is where the swordsman's skill comes into play.
|
|
|
Post by Dan Davis on Feb 22, 2010 23:44:58 GMT
The "secondary bevel" is a by-product of modern sharpening machinery while the "appleseed" bevel is a by-product of "I've been at this for hours and my wrist is tired!".
Both serve the same purpose but the rounded "appleseed" bevel is slightly more effective (less friction, no edge to hang up on) and WAY more aesthetically pleasing IMHO.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 22, 2010 23:54:46 GMT
i understand your point about edge geometry... if you've seen my templar review, you'd see I really stress that point...
however, though I came close to owning a hollow-ground blade, I didn't get it in the end, so I always thought "hollow ground" referred to the sword and the edge... apparently not.
|
|
|
Post by Brendan Olszowy on Feb 23, 2010 0:34:50 GMT
The "secondary bevel" is a by-product of modern sharpening machinery while the "appleseed" bevel is a by-product of "I've been at this for hours and my wrist is tired!". Word not to mention every other part upto and beyond my shoulders...
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 23, 2010 1:42:30 GMT
Nevertheless, I can see how force of impact might "tilt" the edges into each other in a bad way from that angle... I suppose this is where the swordsman's skill comes into play. Actually the force would would tilt the bottom blade's flat into top blade's edge. Another genius resulting from the design of an appleseed! Oblique contact automatically tilts into edge to flat contact.
|
|
slav
Member
Senior Forumite
Katsujin No Ken
Posts: 4,457
|
Post by slav on Feb 23, 2010 1:57:03 GMT
The "secondary bevel" is a by-product of modern sharpening machinery while the "appleseed" bevel is a by-product of "I've been at this for hours and my wrist is tired!". There ya go. It is no surprise that the 'appleseed' or 'convex' edge geometry is so common....it is what will naturally occur when a real human is filing or pounding out an edge. Our hands have that unavoidable tendency to "roll" or "rocker" our tools over and along the surface being worked. It's just (bio)physics. The fact that it happens to be arguably the strongest and most versatile edge is a very nice perk to what otherwise might be a human shortcoming (not being able to hold a tool perfectly flat and straight like a machine).
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 23, 2010 3:02:43 GMT
Secondary bevels exist in the historical record I'm sure. I recall something at mA about that; may have to dig it up.
M.
|
|
|
Post by Brendan Olszowy on Feb 23, 2010 4:14:15 GMT
I cant imagine one dead straight bevel to the edge ever existing. Consider that to sharpen it back even a fraction of a millimetre, and maintain that geometry the entire bevel would have to be shaved down that amount, every time you sharpen it or file out a nick - and nicks would be commonplace on a weak edge like that. It just doesn't work.
Slavia - The apple seed bevel (vs angled secondary bevel as done by machine) is just a case of not being lazy. It's very easy to put a perfectly angled secondary bevel, when drawfiling by hand - but it looks like crap and doesn't perform as well, so you round off the transition.
The rounded grometry is very intentional and not a by product of 'rocking or imperfect form/ human shortcoming' - to think that would be like saying you cant walk in a straight line or keep your car in your lane - we spend so many hours drawfiling we are very adept at it, like a virtuoso violinist hits the note every time, or a race driver hitting his line.
Also please understand that how a maker skims/profiles that appleseed shape has a large degree of cusomisability too. There's infinite variation achievable on that appleseed.
It's art, not accident.
|
|
slav
Member
Senior Forumite
Katsujin No Ken
Posts: 4,457
|
Post by slav on Feb 23, 2010 6:39:48 GMT
Slavia - The apple seed bevel (vs angled secondary bevel as done by machine) is just a case of not being lazy. It's very easy to put a perfectly angled secondary bevel, when drawfiling by hand - but it looks like crap and doesn't perform as well, so you round off the transition. The rounded grometry is very intentional and not a by product of 'rocking or imperfect form/ human shortcoming' - to think that would be like saying you cant walk in a straight line or keep your car in your lane - we spend so many hours drawfiling we are very adept at it, like a virtuoso violinist hits the note every time, or a race driver hitting his line. Also please understand that how a maker skims/profiles that appleseed shape has a large degree of cusomisability too. There's infinite variation achievable on that appleseed. It's art, not accident. I understand this. I was not saying that human error is the direct cause of the appleseed shape, I was rather trying to note that we don't have to go much against our intuition to arrive at it. (i.e.: Give any idiot a piece of bar stock and a file, and he will likely come up with an 'appleseed' bevel for an edge--albeit very bad. But, indeed, it takes a true craftsman to turn it into an excellent cutting device.) So the occurrence and development of such a shape through history is no surprise. I'm just saying that the fact that it is structurally superior plays into our hands quite conveniently...at whatever level of refinement you wish to cite; art or accident.
|
|
|
Post by Dan Davis on Feb 23, 2010 17:04:07 GMT
Secondary bevels exist in the historical record I'm sure. I recall something at mA about that; may have to dig it up. M. Eversberg, This is true: the secondary edge bevel is more common than not - but an "appleseed" bevel IS a secondary bevel, a hand made secondary bevel..
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 23, 2010 16:55:54 GMT
ok,my flat diamond blade has the appleseed geometry, but does lenticular blade? someone mentioned this geometry to me and it sounds more sturdy than flat diamond... or am i just dreaming? i plan on one day having the tang jian custom that jin-shi offers, and if the lenticular geometry is stronger i might go for that. i have had my jin-shi production jian for about a year... cut with it a lot, worked forms, and even sparred... with appropriate kevlar gear... but recently i had a flubbed cut pull my blade into the stand and cost a set to the blade... not real bad, but enough to yank my nerves. most of my friends cant see it, but my students and i can notice it. any suggestions to straighten it without a forge?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 24, 2010 13:16:03 GMT
Taking garrettc's point (edge?!?) as given, and noting that the straight bevel removes more material than the appleseed, would it be advisable to begin with an unsharpened blade especially in our price range? I would think that would lead to more work, and a better result. (appologies if this has been eshaustivly covered in the sharpening threads)
|
|