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Post by Elheru Aran on Feb 17, 2013 19:38:01 GMT
Hello,
As the subject indicates--
I am interested in knowing how jian and dao should balance, ideally.
Comparisons to similar Euros would be quite helpful. For example, should a jian balance like, say, a Viking sword, a cut-and-thrust sidesword, or a rapier? Should a dao balance like a cutlass (heavy hacker) or a saber (light but effective cutter)?
Also, are there significant differences between the balance of, say, a Han jian and a Tang jian, or a goosequill dao versus oxtail versus willow-leaf?
This is mainly because I'm interested in possibly producing wasters for these. Your responses will be very helpful!
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Post by Timo Nieminen on Feb 17, 2013 21:16:10 GMT
For a jian, your pivot point/centre of percussion should be near the tip. The point of balance should be placed to achieve this. For a longish jian, this might mean a PoB about 5-6" from the guard. IIRC, about 1/3 of the distance from end of pommel to tip is typical.
Dao are all over the place in handling, but PoB seems to usually be about 5-8". Most antique dao I've handled, I would call slicers, not choppers. One has been the classic "brutal chopper", and this one is 1.3kg (iirc), and balanced at 8". It's a very heavy dao. Other dao I briefly checked are much lighter (below 1kg), and even if they balance at 8" as well, they handle very differently. Dao pommels can be very light, with the fittings on the grip just functioning as fuchi and kashira to reinforce the grip, and the pommel to have something to peen the tang onto.
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Post by Opferous on Feb 17, 2013 21:41:10 GMT
Huge variety of jian and dao across centuries, so it's a bit difficult to answer. Your typical Qing dynasty jian that most are familiar with has often been compared to a Viking sword, with the average POB usually around 5.5" to 6.5". However, one does need to keep in mind that this is measured from the shoulders of the blade rather than the tip of the guard.
For liuyedao (willow leaf) and yanmaodao (goose quill), they would probably float around the same POB as jian. Oxtail is strange though, since it wasn't a regulation military weapon. Could really be anywhere up to 8" on longer pieces.
These are all sweeping generalizations though. To be accurate, it'd be better to look at the POB from percentages of overall length.
As for Han jian vs Tang jian, hard to say. I haven't had the chance to actually handle any antique Han jian (2200 years old and all) and the one I saw at the palace museum had heavy looking ornate fittings, but they looked like the balance would at least be a little further back due to longer grips than later single handed jian. As for the Tang jian, are you talking about the two-handed model seen in production swords? Honestly, I can't find any information on them in any source books. All the Tang jian I have listed seem to be more courtly fairly short blades (24" to 26" looks like?) and ornate pommels and guards.
Differences in the common three single-handed dao are more along the lines of handling/function than balance.
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Post by Rafael on Feb 17, 2013 22:24:24 GMT
This thread discusses POB for jian usually being around 6inch from the guard, or 35-40% of the distance from the pommel to the point. www.swordforum.com/forums/showth ... of-Balance It is mentioned that in modern over-built jian (compared to historical jian that tended to be lighter and thinner than stuff like what ColdSteel makes these days) the point of balance is moved closer to the guard because of the heavier blade. So to make a sweeping generalization i would say that if you want to make a more historically accurate jian, compare to a CS Gim and make sure your Jian has a POB farther from the guard. Some of this info is attributed to Scott Rodell, but probably the best thing to do would be to contact him at SevenStars Trading and double check to make sure he is not being misquoted. He is a pretty enthusiastic guy when it comes to Jian. If you design a waster Jian and send him one, he would probably even test it out for you and give feedback. |
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Post by Timo Nieminen on Feb 18, 2013 8:26:45 GMT
Having now measured some dao, here are the stats. 1 is a heavy cleaver, 2-6 are slicers. Measurements of pivot point are very approximate, but all are quite far from the tip, unlike jian. PoB is measured from the guard, pivot point (i.e., centre of percussion) from the tip.
# Length Blade Mass PoB PP
1 88cm/34.5" 71cm/28" 1210g 21cm/8" 34cm/13.5"
2 79cm/31" 66cm/26" 830g 18cm/7" 28cm/11"
3 71cm/28" 58cm/23" 620g 17cm/6.5" 26cm/10"
4 74cm/29" 58cm/23" 520g 14cm/5.5" 20cm/8"
5 74cm/29" 58cm/22.5" 850g 11cm/4.5" 21cm/8"
6 71cm/28" 52cm/20.5" 660g 15cm/6" 20cm/8"
7 46cm/18" 35cm/14" 540g 6cm/2.5" 18cm/7"
8 61cm/24" 49cm/19.5" 690g 12cm/5" 23cm/9"
#1 is military style, probably late 19th century, and indelicate pig of a sword. Similar weight compared to many European cavalry swords of the time.
#2 and #3 are possibly military, but probably not cavalry swords. Probably 19th century.
#4 is a court dao, late 19th century, perhaps for a guard officer.
#5 is a falchion-type dao, with an S-guard. Missing the grip, so the weight should be a little higher and the PoB a little closer in. Could be 18th century.
#6 is a straight dao, also missing the grip. Age unknown, but old.
#7 is a little dao with a knuckle guard (like a butterfly dao, but single). Could be a modern fake.
#8 is a huge knife, no guard. Basically a big Chinese seax. These are often described as "river pirate knives" or similar.
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Post by Rafael on Feb 18, 2013 21:19:59 GMT
Can you post a pic of the river pirate knife please? Or if you have time post pics for all of these please!
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Post by Timo Nieminen on Feb 19, 2013 2:36:59 GMT
At the moment, I have a photo of it and the falchion. The knife: The S-guard dao: The letters are where I measured the thickness of the blade: A: 4.5mm, B: 3.9mm, C: 4.0mm, D: 3.0mm, E: 2.6mm If the weather improves (my camera really needs outdoor light, and it's been raining for days), I'll see if I can photograph the rest. Attachments:
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Post by Lancelot Chan on Feb 19, 2013 20:04:29 GMT
I've done some research on this area, from antique collections that I came to handle personally and from antique stats published on the net, mainly in Chinese.
The POB of Jian and Dao are very surprisingly the same, around 40% of the total length, measuring from the hilt. If it's an unmounted blade, the POB would usually sit around the middle of the total length.
This POB trend is a lot different from what wushu practitioners nowadays prefer, but such were the swords meant to be used back then. And for me who also practice Chinese swordsmanship, the real deal guys know how to make use of such forward POB for one's own advantage.
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Post by Timo Nieminen on Feb 19, 2013 20:51:32 GMT
My examples agree with this. They balance at 43%, 39%, 42%, 41%, 36%, 48%, 37%, and 39% of total length. This is for a diverse range of dao, including some of very different handling. Which leads me to say this: mass and PoB are not enough to say how a sword handles. The extra thing you need to know is the moment of inertia. The location of the (forward) pivot point/centre of percussion provides this (indirectly, but for practical purposes, this is probably the most useful quantity). Warning! Terminology varies! Engineers use "moment of inertia" to mean resistance to bending; physicists use it to mean resistance to angular acceleration (how hard it is to rotate something, in the same way that mass tells you how hard it is to move something). The 2nd meaning is meant here. "Centre of percussion" also has two meanings; a lot of modern sword people use it to mean "node of vibration", which appears to come from a misunderstanding of the original meaning. The original meaning is synonymous with "pivot point". The current Wikipedia page looks OK: en.wikipedia.org/wiki/Center_of_percussion |
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Post by Elheru Aran on Feb 20, 2013 17:06:32 GMT
Gentlemen-- Thanks very much for your input  So in general, jian and dao should balance almost halfway up their total length, closer to the hilt than the tip, and they should hit hardest at more or less the tip of the blade? Is that a correct generalization? This is pretty convenient as wooden wasters tend to have a fairly far out balance compared to steel swords, so the handling is already similar. Any suggestions on refinement? Details you might like to see? Any comments on any Chinese martial arts wasters currently on the market that you have handled? Thanks again! Keep it up |
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Post by Timo Nieminen on Feb 23, 2013 9:33:43 GMT
Sounds OK. For a dao waster, aim at 40% of total length, and it should be fine. I have a cheap polypropylene dao waster that balances about like that, and it's acceptable. Not great, but it's closer in handling to the real thing than most wasters.
I don't think you can generalise to that. Are you referring to having the centre of percussion/pivot point close to the tip? First, the pivot point/centre of percussion is not necessarily where a sword will hit hardest at (hitting closer to the hilt will often give a harder hit, but this is complicated by cases where the speed matters a lot, like when hitting a lightweight or squishy target). Second, dao don't appear to have PP/CoP close to the tip, but a long way from it.
But aiming to put the PP/CoP close to the tip will be good for jian. If the point of balance has to be somewhere "unrealistic" to achieve this, I think this is worth doing - for a jian, PP/CoP matters more. A jian should balance like a little longsword - when you move the sword around, the tip should stay nicely stable where you had it placed (which is what having the PP/CoP at the tip does for you). And it doesn't hurt when you want to slice with the very tip.
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Post by Rafael on Feb 23, 2013 14:23:57 GMT
Very cool pics. Thanks for sharing!
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Post by Elheru Aran on Feb 23, 2013 20:18:49 GMT
I guess what I meant was center of percussion, yes. 'hit hardest' is more along the lines of a 'sweet spot', which I suppose isn't necessarily the same thing!
Playing around with a dussack waster I'm putting together, which is slightly similar to an oxtail dao-- I'm guessing the PP/CoP should be behind the tip a ways? Makes sense for cutting swords...
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Post by Timo Nieminen on Feb 23, 2013 22:31:26 GMT
I don't why dao have their PP/CoP where it is, but I can think of two possibilities. The first is that the makers simply didn't care where it ended up, perhaps because it doesn't matter so much on a slicer (unlike choppers, where it matters for chopping, and thrusters, where it matters for point control). Perhaps because you want to hit further up the blade.
The second is that having it far from the point might actually be desirable. The PP is relative to the point about which the sword rotates, which, if nothing else is specified, is taken to be at the grip, about where the 1st two fingers are. As far as corresponding to a sweet spot, this implies that the arm is stationary, and one cuts from the wrist. Is this how one cuts with a dao? It also assume that the sword strikes the target stretched straight out, chopping rather than slicing with the sword at an angle. Cutting from the shoulder (with the elbow bent) lets you have the sword at an angle, rather than lying straight along the with the line between centre of rotation and point of impact. Both the angle of the sword and the shift of the centre of rotation shift the PP/CoP, the first outwards, and the second inwards. For some cuts, the "traditional" PP being far from the point will translate into the actual PP being near the tip.
I'd be interested in knowing there the PP/CoP is on antique oxtails, since those are optimised for slicing with the tip. I have a (modern) parang nabur, which can be described as an oxtail dao from Borneo, has PP much closer to the tip than the dao upthread.
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Post by AlvaroWang on Jul 30, 2014 6:21:46 GMT
Sorry for digging this thread up, but i thought it would be better than just creating a new topic.
I was thinking about taiji jian and the center of percussion. Basically, from what I understand, the CoP depends on the rotational pivot. My teacher taught me to pivot the sword using the point of balance while maneuvering it. Considering this, should the CoP be assessed using the wrist or the PoB as reference?
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Post by Timo Nieminen on Jul 30, 2014 6:55:56 GMT
The CoP/pivot point is defined as the point about which the sword rotates when you apply a purely sideways force at the grip. You're not trying to twist the sword; if you were holding it at the PoB, it wouldn't rotate. The point the sword rotates about depends on (a) where you apply the force relative to the PoB, and (b) the sword's rotational inertia (i.e., moment of inertia). You could interpret this as using the PoB as the reference. For some pictures, see www.peterjohnsson.com/the-making ... ong-sword/ where his "forward pivot point" is what I mean by PP/CoP. |
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Post by Timo Nieminen on Jul 2, 2015 5:40:00 GMT
For a further reply (re-reading this thread):
For maneuvering the sword, the CoP/PP is where the sword will naturally rotate about when you apply a sideways force to the grip, without applying any torque about the grip. This is why CoP/PP at the tip can be good for thrusting swords: if you are facing somebody, with sword pointing at them, and move the hilt sideways, the sword automatically still points at them. (For rapiers, where you are likely to want the sword to rotate about a point some way down the blade where it is in contact with the opponents blade, you want the CoP/PP near the point where the swords will be in contact. Likewise, for sword-and-buckler, CoP/PP near the point of contact with buckler is good.)
This has most effect if you are moving the sword quickly. For slow form work, it doesn't matter. For slow work, it takes very little torque to move the blade about whatever point you want. But see below for more.
For CoP/PP as a "sweet spot" for striking, you want the CoP/PP relative to (assessed using) the point about which the actual strike will rotate about. For cuts from the shoulder or elbow, CoP/PP relative to the grip doesn't mean much (see comments upthread about CoP/PP on dao). But if the cut is from hand/wrist, with rotation about the grip, then CoP/PP relative to the grip matters.
Back to your question: rotating the blade about the point of balance for a cut makes for a lousy cut. This is IMO not the right way to cut. For just moving the blade as you turn around to face a new threat, might be OK. Try it at speed, and see if it's natural. If you have to fight the sword, it's wrong (IMO). Of course, for a particular style/school, the teacher is always right in that it's the right way for that style/school is what the teacher says. But if you want it to be martially sound, you shouldn't have to fight your own sword. It should work with you, and you with it. At speed.
(Sometimes, moving and cutting about the point of balance is good. The dip-the-tip and cut up at the underside of the opponent's sword hand is an example. Because it isn't a "natural" movement of the sword, it doesn't hit very hard, but the fingers are a delicate target, so it works.)
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