[Chris Fields]

Justin, I see what you are saying, but I would have to disagree, (not trying to be rude, and I definitely could be wrong), especially in the original context of what Thom was wanting to do, and that is compare like swords to one another. If you have two similar swords of similar weight, size, and CGs, they will handle similarly, but small changes in either Total Weight, or CG, will give different feel. I personally think if the correlation of the two variables is done correctly, you categorize blades by there type as well as against one another.

If you move any mass on a sword on either side of the CG, it will change the CG, there is no way to avoid this, unless the masses changing are different on each side. For the way a sword is built, it will be very, very difficult to not change the CG.

In my 20 or so years of Kung Fu, 15 years of stage combat, and at least 6 years of WMA, JSA, and Chinese swordsmanship, I have handled many many types of swords, from heavy stage pieces to modern copies of antiques, to a few actual antiques. I could definitely use more experience with actual antiques, as I am more use to heavy stage stuff. A 4 lb single hand arming sword with a 4.5" POB is light to me. I am not a big buy or anything, it's just what I am used to because I have trained with them for so long. With this experience though I feel I could use CG vs total weight as a good predictor value of "Liveliness". My thoughts could be skewed though because total weight vs CG has a larger effect on the heavier blades over the lighter more historical blades, so maybe it's not enough of a predictor for more historical blades.

Please look at some charts I'll post tomorrow and see if you agree with either of the two of them. One has mass and POB equally contributing to the "Liveliness" factor, the other, which I agree with more, puts mass as a larger factor over the POB in the "Liveliness" factor. The two charts arrange the Albions differently. Please take a good look, and honestly check them to see if you agree with one of the two. If you don't agree with either, then we can toss them out =) hehe.

Thom, looking forward to those test! If the charts I created make everyone scratch their heads, then adding that inertia variable maybe whats needed to solve this.

Jean, I'll try to add in your sword tomorrow as well =)

[Justin King]

My analogies are much too vague to withstand a semantic critique by an engineer, they werent intended for that and I know better than to argue with engineers anyway so I'm going to hope I made my point and let it go so as not to derail Thom's thread.

[John Gnaegy]

I think handling characteristics could be boiled down to torque.

You have as the fulcrum point the weight bearing part of the primary hand, and the distance from there to the center of balance, and the weight of the sword. Let's assume the primary hand (say the right hand, forgive me lefties) is held close to the guard, maybe half an inch away from the guard? And the weight bearing/controlling part of the primary hand I'd guess is between the first and second knuckles, maybe the second knuckle, so let's say an inch from the frontmost part of the hand. So the fulcrum is 1.5 inches in from the grip side of the guard. Figure the distance from there to the point of balance to get the length of the lever arm. Multiply that by the weight of the sword, and using the correct units you've got a torque value in foot pounds. You can go one step further and figure angular momentum relative to time, but it's telling you the same thing.

Now that doesn't figure in length, because that's irrelevant to the calculations, so you just have to assume that length of the grip and blade are Something Reasonable, and that air resistance is ignored. What do you think?

http://en.wikipedia.org/wiki/Torque

You know there's one other thing, the width of the grip. If you had a grip that was the width of a human hair you'd cut off your fingers swinging the sword, but if the grip is 3 inch diameter no problem. So maybe torque divided by the thickness of the grip. Actually it's the surface area of the grip around the weight bearing part of the hand that makes the difference, but that's directly proportional to the simple thickness of the grip. So for the purposes of comparing different swords handling characteristics, maybe torque / grip thickness would give a good idea. If you wanted to go nuts you could use the circumference but you'd probably have to measure each sword's grip.

[Chad Arnow]

Chris, you said:

[Chris Fields]

Justin, Chad, I understand what you are saying, and I think most the people reading this understand as well. =) Please check the charts I'll post tomorrow. It would help me greatly if you had an example of two swords with exactly the same stats that handled differently. Of all the Albions I am looking at, none of them have the same stats, so I don't have a good comparison for that on the charts. I have some that are very close, but not exact.

John, torque was the first thing I had in mind, the problem I had with that is the Torque values are all over the place for all the Albion swords when I plotted them out, and didn't give a good indicator of "liveliness". I suppose I could sort them by there torque values, but there will be no pattern to it. Using torque, both mass and distance of the POB from guard are equally contributing. However, I believe weight is a more important factor than POB. My second chart weights the mass more important, and I think gives a better "liveliness" number. But we'll see what everyone else thinks. =)

Btw... Thom, sorry if I am steeling your thread, I am only trying to help you reach the goal in your first post. =)

[John Gnaegy]

[Chad Arnow]

Chris,
Granted, finding exact matches will be hard, but there are many that are close enough for decent comparison. Focusing on exact matches misses the larger point (forest for the trees and all that).

Take these two (using Albion's published stats):

Albion Baron:
Total length: 47.375"
CoG: 5.25"
Weight: 3 lbs 11 oz

Albion Regent:
Total length: 48"
CoG: 5.25"
Weight: 3 lbs 8 oz

We're talking fractions of an inch in difference in length and 3 ounces in weight, but the same POB. The original system proposed in this thread and any system that just adds POB might show these swords as similar (not exactly the same) in handling.

But they aren't similar, not by a long shot. The handling difference is large; some might say night and day. The handling difference isn't just because one weighs three ounces more and is slightly shorter. The blade and hilt fittings are nothing alike.

The Baron's pommel is thicker toward the grip. The Regent's is thicker on the peened end. That will make a small difference, even if both pommels weighed the same (which they likely don't). You've moved the mass. The Regent blade is thicker and narrower with a much different cross-section. Etc., etc.

Even if you could get a Baron and Regent with the exact same length, weight, and POB (rather than slightly different as they are) they still wouldn't handle the same. They're too different.

My point, for anyone that cares, is simply that length, weight, and POB don't tell us enough. Cross-section, stiffness, distal taper, general mass distribution, etc. can't be ignored. They determine handling far more than those three basic static stats. People are too obsessed with POB.

[Chad Arnow]

I guess I don't see the point of all this. Are you trying to find out which sword handles better based on numbers?

For example (and it's a gross generalization on my part), should a Type XII and Type XVIII handle the same and have the same arbitrary handling criteria applied to them? The Type XII will often be more of a cleaver (have more blade presence and likely a farther POB), while the XVIII needs more tip control for thrusting and will in many cases have less blade presence (closer POB). So if the Type XVIII has a closer POB, does that mean it's a better sword than the Type XII? No, they have different usages that factor into their designs.

Is the point of the system to find out which is more "lively"? Again, some swords types will generally feel more lively than others, by design. And just because it's lively doesn't mean it's a good example of its type. Plus, we don't all have the same ideas about what lively is, anyway.

We moderns like to get hung up on numbers and neatly organized things.

Unless you can factor in all the elements that go into handling and have the system adjust to different Oakeshott types and intended purposes, you won't have anything that really helps.

[Chris Fields]

Thanks Chad, I really do understand what you are saying, don't think I don't, or that I don't care. Which of those two swords would you consider more "lively"? Just curious if one of the charts I came up with predicted it.

I thought about stiffness and cross section, those terms are captured by the moment of inertia calculations. I didn't think the human body can pick up on the small differences in moments of inertia from sword to sword, but that could be a bigger variable than I thought. If so, then Thom's inertia tests will gives us the third variable we'll need.

I still don't think it's as complicated as everyone thinks. Whats more complicated is that each person has a different idea of what feels good and what doesn't. So trying to get a "liveliness" factor that everyone can use as tool to compare one sword to another may be tricky. My second chart I believe is on the right track, in that it shows a trend of different types of swords gathering together, and they can therefore be separated into groups. Once separated into groups they can be compared against each other in there group or against all the swords as a whole. There will be some overlap, say from viking/saxon to medieval single, etc, but I think it still works. Hopefully you all will agree. =)

The point of this I believe was to able able to categorize a swords "feeling" based on numbers, so that if you want to buy something from the internet, and you have a general idea of swords handle, you can have a good number to tell you how the sword may "feel" compared to others you may already own.

I think you'll see that you'll be able to seperate out cutters from thrusters in the charts I came up with, I'll see if I can get some rapiers in there. At least give it a chance =)

[Chad Arnow]

I finally found an old post I thought I remembered that goes into POB stuff:

[Chad Arnow]

[Chris Fields]

I have to disagree with Peter on that one, swords, and how they are shaped are far different from a rod with a central balance point from which mass can vary that drastically. It's apples to oranges. Like I stated, most swords have very similar moments of inertia relatively speaking, which is what describes what he is saying. The moments are so close that I didn't think a person could distinguish them, but again, I could be wrong. The moment of inertia may have a higher impact than expected.

The charts were worth my lunch break =), if they are completely wrong, no biggie, it is an interesting idea to try to capture. =)

I don't remember where those two landed on the chart, I do remember the chieftan was the least "lively" and the gladius's where the most "lively". That alone may make or break the charts =)

[Bill Love]

I think I know the solution here, and that is to admit that everyone is essentially correct from a modern standpoint. The old ways weren't inferior, just different. In the golden age of air racing, engineers would regularly build the most precisely calculated aircraft only to have them fold up at speed or get clobbered by designs that began as chalk outlines on hangar floors. Ask an aeronautical engineer today, and they would probably tell you that the latter couldn't be and never had been done so simply-the problem being, of course, that it had been, many times. I once watched an old timer expertly balance a 70 year old wooden propeller using brass nails and a tack hammer, and he gave me the dirtiest look when I asked him what he was using for measurements. I have a sneaking suspicion that most of the finest surviving pre-Renaissance swords were built by smiths who had never even heard of math and who instead relied on what had worked in the past along with feedback from their customers. Considering that a largely illiterate society was a hallmark of the Middle Ages, there really is no other explanation.

[Thom R.]

I thought I stated my original intention quite clearly in my first post. i was searching for a way to easily get an understanding of a sword's handling characteristics and compare very similar swords (within type) via a back of the envelope quick method using the available numbers since i can't hold every sword in my hand in this lifetime . I think I also said very clearly that any attempt to correlate any kind of mass balance ratios across type (Baron/Regent) is, probably not meaningful.

Now I have to say that I have an example that does support what Chad and Justin are saying however. I have a friend here who I have practiced martial arts with for many years who has an A&A ringhilt sword and I have always liked that sword so when one came available second hand I bought it. Having had them both over here at my house we examined them a little bit together side by side. You would be very hard pressed to visually see much of a difference (other than cosmetic), the hilt components are an exact match, the lengths from nut to tip are within a mm of each other. we traced the profiles on paper and again, indistinguishable. I have to complement Craig on these swords they are very very nice weapons and the differences just go to show that they are hand crafted. However, my sword weighs 1088 g and my friends weighs 1118. So 30 g difference. now that does not seem like much, but we did a blindfold test, both of us, and we both can pick out which is which. i believe that the difference, although it may lie in the tang, is probably in the distal taper along the spine of the sword (type XVIII), so is probably out between the POB and the tip and therefore that slight difference in mass has a noticeable feel in terms of the moment felt in the hand when you grip the sword behind the cross............ so I have to say yes, small differences can be felt as it does depend on the mass distribution and where those differences in mass lie. I am just talking about holding them, not even really swinging them around.

As far as numbers in general, I am sort of prone to be aligned with the principles of the enlightenment, so tend to be very supportive of the observational method as a means of improvement, and I worry about the exact opposite thing that you do Chad the tendency of people to cling to unsupported opinions, beliefs, conspiracy theories etc etc which imo I see permeating society more and more. If anything I think we have taken a step backwards from the scientific method as a society the past 20, 30 years as things have become more and more political and people have become... less numerate. anyway your mileage may vary but i think you have to be willing to put some data on the table sooner or later at times. otherwise there's no way to move forward between opposing opinions.

and of course jean thats an incredible sword i am so wanting to hold it sometime . just back of the envelope its what 2230 grams or so and would have a MI of 20 and basically fall right on that trend of nicely balanced big swords in the original chart, albeit just off that chart to the right. cool sword! that sword probably has a lot of momentum to pull through a cut i would think. keep a firm grip on that one!

so here is my start on the next phase of this - i made a rig, - needs some improvement - for measuring moment force on my swords. scrounged around the shop, found some round aluminum plate - drilled it - attached a bolt to it that ends in a hook, found a nice dowel to use as a balance beam, sanded one side flat on the belt sander, cut a groove in the top side and inserted a triangular file into the groove on the dowel and chopped the excess length of file off with the dremel. then went by the hardware store tonight on my way home and bought a bunch of large washers for counterweights. used some lightweight cord to hang the counterweight on the sword, and pulled out my lightest sword which is my Tinker Type XVIII. I put the sword on the balance beam right at the handle/cross juncture and measured and marked off with a little tape 5 cm behind the hilt (in this case that would be 15 cm from the POB) which would correspond to the midpoint on my hand/wrist. well, guess what. i bought enough washers to measure the moment on the pommel end (26.2 cm from the POB), but uh, didn't buy enough washers to find the moment on the 5 cm mark even for my lightest sword . oops. so back to the hardware store tomorrow. now i am wondering if the whole rig is going to be big enough to pile on enough weight for my larger swords. but hey experimenting is half the fun!

[Bram Verbeek]

I added volume, because it is easiest to measure. I can stick my rig into a tube and measure how much water it takes to get to the next 5cm mark and calculate the mass, I cannot simply put a scale under it. Torque, or total weight per total length, will not do, since acceleration takes time equal to all the parts of mass times the parts of length from the point of rotation squared. So what you will need to do, is calculate each tiny part of mass and multiply it by its length from the cog squared. Since I like math, but do not think it necessary to spend my days calculating swords, I took 5cm increments to calculate this.

I think that the changes in profile and distal taper that change the angular momentum but not the cog and total weight are exactly what Chris and Chad refer to.

As a side note, we can only hope to achieve close resemblances of midieval swords, but since we are not the illiterate smith that has made swords all his life, we'll have to make do with math to make sure our examples resemble those old-timers better

[Chris Fields]

Ok, here we go, just got into work. I haven't had a chance to put in anything but Albion swords. But here are three different "liveliness" charts each being dependant on slightly different variables. See if you agree with one of them, or if one does a better job, or if they are all just out in left field somewhere. =)

1st, both total mass and POB are weighted equally. The first graph shows the sword names, the second shows the sword types.




2nd, the Mass is weighted more important than the POB.




3rd, the POB is weighted more important than the Mass.




Personally, i think the 2nd graph does the best job from my experience. Does anyone disagree with how the swords are ordered in that chart? I also like how you can see the trend of the sword types starting to separate out better than the others, so we could look at each type more closely with that chart. Chad, each chart did predict which sword you thought handled more "lively" but the spread was very close as you suggested. The first chart spread them out further though, so maybe that one may a better indicator. Thanks

Also, if you look at these charts, and see any swords in the wrong order, please point that out, that will help us find out if one or any of these charts are worth while. Thanks

[Chris Fields]

Oh... Jean! I love that sword btw. Here is where it comes in

On the first chart, it is second to last place on the "liveliness" just ahead of the chieftain with a score of 24.5

On the second, it comes in dead last with a score of 9.9

On the third, is comes between the Vinland and the Huskarl at 11.9

Again, those charts were just on Albion swords. If one of the ends up being correct to what people think is a good "lively" factor, then we can include every sword we can think of. I'm sure you'll see heavy stage combat blade very low on the charts and rapiers and such on the end. Each type of sword though has a different sort of "liveliness" that it will want to center around. So, say you want to compare the single hand cutters, well, you may not want a cutter with a higher "liveliness" factor than the others, you may want it to fall around the middle of the single handers. Make sense? On the same note, you may want a two hander that centers around a low "liveliness" factor, and a rapier that centers around a higher factor. So, just because it may score higher or lower, doesn't mean it's better or worse, it's just a comparison for someone to make a judgement on the "feel" of a sword without actually holding it.

So, maybe instead of calling this a "liveliness" factor, maybe it could be better called a "handling" factor. thanks

[Chad Arnow]

[Chad Arnow]

I personally think that calling the Baron, Duke, and Chieftain "longswords" will invite unfair comparisons to true longswords. I think they're better categorized as "great swords." But that's just me.

[Chris Fields]

So do you disagree with any of the placements in the Second graph? Just curious. I think I will change the name to "handling" factor over "liveliness" factor. Yes, they are both subjective, but as long as the trend of the that line is generally correct, then a person can find their preference on the line. Some one may like swords that are around the average number of single hand swords, others may like swords that center around the long sword average number. Again, if the general trend line isn't correct, then this is a mute point. =)

Oh, also, I called theDuke, Viceroy, Regent, Baron, and even the Chieftain a "longsword" only because that is what Albion has them listed under, but I agree they should be considered a different type. It's neat how they seem to separate themselves as a group on the second graph. I think I may still consider the Viceroy a longsword though, hmmm.