Sliding weights

Rivkin · 2nd July 2005, 01:30 AM

I truly believe that any sliding weight would be totally cool, fancy, and useless. I see no reasonable advantage over permanent placement of some weight at the sword's end, etc.

Ian · 2nd July 2005, 04:33 AM

This topic is closely akin to the physics of hitting a baseball.

BTW, I notice that the on deck hitter often puts a ring weight around the bat barrel to take some practice swings, but does not try to emulate that weight in the bat itself. It slows down the bat speed and if the bat is overly heavy too much power would be lost -- kinetic energy is proportional to the square of velocity, but only linearly related to mass.

Ian

ariel · 2nd July 2005, 10:59 AM

I remember years ago seeing a Chinese throwing knife that always hit the target with a point and got imbedded quite deeply. Apparantly the secret was a hole drilled within the entire blade along the whole length and filled with mercury. It moved freely in this channel and changed the center of gravity. Was very impressive.
I guess, the same principle as discussed here.

Jens Nordlunde · 2nd July 2005, 03:17 PM

Montino, you may be right, we will hopefully know later, but I agree with you that a heavy weight getting stuck at the tip could be fatal.

Ariel, an interesting mail about the use of mercury in the blade, I can imagine that the result have been impressive.

Jens

Mare Rosu · 2nd July 2005, 08:56 PM

Jens
You are at it again, from magnetic blades to now sliding weights.
Are you sure you moved to Switzerland and was not run off, to hide/escape?

Anyway the idea of sliding weights is a good one, while I have little to add to this subject I do think a distance related subject might be of interest to you and others and that is; Atlatls and banner stones used with them. I have found these banner stones in years past and this is just two web sites on their use. http://donsmaps.com/atlatl.html and http://www.primitive.org/atlstealth.htm.
To me a very interesting subject you have started Mr. Jens

Jens Nordlunde · 3rd July 2005, 01:38 PM

Interesting subject you raise Gene. You are right, this is about giving the weapons more dynamic power, and the links you give, show that this has been very important for thousands of years. This shows, that people in ancient times did know a lot about dynamics, although they did not know the formulas. When throwing a javelin or a light spear, it is important that you ‘arm’ is long, and here the Atlatl helped a lot, as the longer the ‘arm’ the more power you could put behind the throw. Interesting also to see that they adapted the length of the Atlatl to the surroundings, but what I find really intriguing is the use of Banner Stones, as I did not know such stones were used. I wonder how they figured out that the use of Banner Stones would make the use of the Atlatl more silent.

fearn · 3rd July 2005, 03:03 PM

Hi Jens,

This is getting a bit off subject, but I was partially thinking of atlatls when I was talking about weights absorbing shock in a sword.

The other source of inspiration was a dha-style sword I made out of a machete. I very quickly learned that there were only two good handholds on the long handle: at the end, and about 1/4 of the length from pommel to tip. This was because the sword flexed on impact, and holding it at other points was a recipe for getting a very sore hand (the best handholds were at the nodes: end, 1/4, 1/2). Personally, I think that there are a lot of hidden shock-minimizers in well-designed dhas and other long-handled blades. Otherwise, they wouldn't be worth swinging.

There's no reason that a moving weight on a blade couldn't serve a similar shock-absorbing function, but that's another design question entirely.

Personally, I'm surprised that the atlatl people weren't talking about tuning their dart and thrower systems to make the things accurate. After all, if the dart flexes the wrong way, it's not going to hit whatever the person was aiming at.

Fearn

2nd July 2005, 08:56 PM	#5
Mare Rosu Deceased Join Date: Dec 2004 Location: USA, DEEP SOUTH, GEORGIA, Y'all hear? Posts: 121	Banner Stone Jens You are at it again, from magnetic blades to now sliding weights. Are you sure you moved to Switzerland and was not run off, to hide/escape? Anyway the idea of sliding weights is a good one, while I have little to add to this subject I do think a distance related subject might be of interest to you and others and that is; Atlatls and banner stones used with them. I have found these banner stones in years past and this is just two web sites on their use. http://donsmaps.com/atlatl.html and http://www.primitive.org/atlstealth.htm. To me a very interesting subject you have started Mr. Jens

2nd July 2005, 01:30 AM	#1
Rivkin Member Join Date: Dec 2004 Posts: 655	I truly believe that any sliding weight would be totally cool, fancy, and useless. I see no reasonable advantage over permanent placement of some weight at the sword's end, etc.

2nd July 2005, 04:33 AM	#2
Ian Vikingsword Staff Join Date: Dec 2004 Location: The Aussie Bush Posts: 4,453	This topic is closely akin to the physics of hitting a baseball. BTW, I notice that the on deck hitter often puts a ring weight around the bat barrel to take some practice swings, but does not try to emulate that weight in the bat itself. It slows down the bat speed and if the bat is overly heavy too much power would be lost -- kinetic energy is proportional to the square of velocity, but only linearly related to mass. Ian

2nd July 2005, 10:59 AM	#3
ariel Member Join Date: Dec 2004 Location: Ann Arbor, MI Posts: 5,503	I remember years ago seeing a Chinese throwing knife that always hit the target with a point and got imbedded quite deeply. Apparantly the secret was a hole drilled within the entire blade along the whole length and filled with mercury. It moved freely in this channel and changed the center of gravity. Was very impressive. I guess, the same principle as discussed here.

2nd July 2005, 03:17 PM	#4
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	Montino, you may be right, we will hopefully know later, but I agree with you that a heavy weight getting stuck at the tip could be fatal. Ariel, an interesting mail about the use of mercury in the blade, I can imagine that the result have been impressive. Jens

3rd July 2005, 01:38 PM	#6
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	Interesting subject you raise Gene. You are right, this is about giving the weapons more dynamic power, and the links you give, show that this has been very important for thousands of years. This shows, that people in ancient times did know a lot about dynamics, although they did not know the formulas. When throwing a javelin or a light spear, it is important that you ‘arm’ is long, and here the Atlatl helped a lot, as the longer the ‘arm’ the more power you could put behind the throw. Interesting also to see that they adapted the length of the Atlatl to the surroundings, but what I find really intriguing is the use of Banner Stones, as I did not know such stones were used. I wonder how they figured out that the use of Banner Stones would make the use of the Atlatl more silent.

3rd July 2005, 03:03 PM	#7
fearn Member Join Date: Dec 2004 Posts: 1,247	Hi Jens, This is getting a bit off subject, but I was partially thinking of atlatls when I was talking about weights absorbing shock in a sword. The other source of inspiration was a dha-style sword I made out of a machete. I very quickly learned that there were only two good handholds on the long handle: at the end, and about 1/4 of the length from pommel to tip. This was because the sword flexed on impact, and holding it at other points was a recipe for getting a very sore hand (the best handholds were at the nodes: end, 1/4, 1/2). Personally, I think that there are a lot of hidden shock-minimizers in well-designed dhas and other long-handled blades. Otherwise, they wouldn't be worth swinging. There's no reason that a moving weight on a blade couldn't serve a similar shock-absorbing function, but that's another design question entirely. Personally, I'm surprised that the atlatl people weren't talking about tuning their dart and thrower systems to make the things accurate. After all, if the dart flexes the wrong way, it's not going to hit whatever the person was aiming at. Fearn