Tsuba and balance points -- myArmoury.com

Tyler Weaver · Posted: Sun 02 Oct, 2005 7:27 pm Post subject: Tsuba and balance points

For the longest time, my iai-to has been bothering me. It has a balance point of some 7" forward of the guard, which is on the extreme high end of the range even for katanas, which tend towards blade-heaviness, and which makes for a much slower recovery than I would like. It has a double-D Musashi-style pierced tsuba made of what I think is blackened brass, and which could easily be swapped out for something more substantial in iron to move the point of balance back.

Which brings me to my point - does swapping out the tsuba on a Japanese sword (in this case, for one probably two or three times heavier) actually change the balance to any appreciable extent, enough to make it worth my while to drop sixty dollars on a replica tsuba (small change compared to my sword's original cost) and void the warantee by taking it apart to put the new one on? And if it wouldn't, any suggestions?

Alexander Ren · Posted: Sun 02 Oct, 2005 8:21 pm Post subject:

Here is an idea that I just thought of. I have no idea if it will work because I have never tried it. You could take fishing weights and attach them to the tsuba with zip-tyes. You can get them from any wal-mart, k-mart, bait-and-tackle shops for a few cents per ounce.

Let me know how it works... Alex

Benjamin H. Abbott · Posted: Mon 03 Oct, 2005 2:27 am Post subject:

Interesting. I have a couple of Purpleheart padded longswords. They're probably the best padded swords west of Hong Kong (heh), but the balance point seemed a bit far out at 5.75 inches from the 1 inch wide cross (6.75 inches from the hand). So I've wrapped the grips with copper wire, pulling the balance point back to about 4 inches from the cross and pushing the weight of each sword up to close to three pounds.

Probably not what you want to do in this case, though...

Alexander Ren · Posted: Thu 06 Oct, 2005 8:10 pm Post subject:

Cole Sibley · Posted: Fri 07 Oct, 2005 3:35 pm Post subject:

I'm far from an expert on Japanese (or any) swords, but remember, if you pull the balance point back with weight ahead of your 'power hand' (more specifically rotation point) you will also be pulling the center of percussion in (towards your hand). This may or may not be desireable, depending on your sword. If you add weight to the pommel (forgive me, can't say the Japanese name), it will still move the COB back, but move the COP out, which also may or may not be desireable.

I suppose if you never cut or plan to do something similar, the Center of Percussion would be less important than the Center of Balance. However, if cutting is important to you, moving the COP can have some rather dramatic effects.

P.S. I was under the impression brass is heavier per-volume than iron or steel, but of course a 'solid' tsuba would probably increase in mass over a peirced type.

Tyler Weaver · Posted: Fri 07 Oct, 2005 7:48 pm Post subject:

Well, seeing as how this is an iai-to with a zinc/aluminum blade, the CoP isn't really very important. Wink

Another, cheaper option for me would be to find out if there's any extra space in the slot in the hilt the blade's tang goes into and fill it with lead or something else that's heavy - which is also perfectly authentic as far as balancing a Japanese sword goes.