Breaking only the second board
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Chizikunbo
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I just recently learned this, boards without spacers, break from the bottom to the top; with spacers break from the top down. If the power of the strike is controlled or is not enough, without spacers, only the bottom board will break.
I understand that if to wood is warped it can also contribute to this, based on how the wood is assembled. Note GM Ahpo breaking in this picture
The unique thing about GM Ahpo is that he can actually break any board/brick out of a sequence on request ;-)
Take care,
--Josh
Funny you mention this, Jeff—I was doing some break-training the day before yesterday and the same thing happened to me—twice! (with the same top board...)
IT can happen in cases where the top board is, for one reason or another, a lot tougher to break than the one on the bottom: so I've noticed, for example, that where most boards have distinct vertical sections running horizontally across them, certain boards do not—when you look at them edge on, there are no division lines evident. Those boards are usually a sign of trouble. It turned out that I had one of those as my top board in both attempts. On the third go, I just used that single, homogeneous board (for lack of a better term), and I did break it—but I had to use an amount of force that normally would break a stack of two `normal' boards. And I've had tougher cases than that. But it's hard to see how that kind of thing would happen consistently to a given student... :idunno:
That is too scary for me!! :xtrmshock
While what exile is discussing can happen, if this happens all the time, it's more likely that he's not focusing on the target properly. If you consistently aim at the top of the front board, then either the back board will break or neither one will. He needs to aim for a point 1/2 inch behind the back board to break all of them.
I break like this all the time.....I do it for special effects when I want the kids to think it's cool. It's basically transference of force. If you pull back on the power a little bit before you strike, the energy will transfer into the 2nd board and break it. So in order for you to break both boards. Imagine the target is actually behind the 2nd board and completely follow through with the strike. Do not pull back on the power,
Chizikunbo
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Hi,
actually KJN Ahpo (9th dan) is quite an interesting practicioner, he has 60 years of MA experience under his belt, and is quite renown for his ki gong demonstrations, he is known to shake plant leaves from afar and other such feats, that are seemingly unique to him, and him only. He mixes elements from his Huna (kahuna) hawaiian culture and 35 years of chi kung training.
Interesting stuff in any case ;-)
--Josh
Mr. Paszkiewicz,
Actually GM Ahpo had tested and my understanding passed his 8th Dan examination under the Soo Bahk Do federation. But due to politics, GM Ahpo wasn't awarded an 8th Dan certificate. Long story short, my instructor was apporached to resolve the situation. The result was that GM Ahpo was promoted to 8th Dan in Tang Soo Do by KJN Kim.
Thanks,
Patrick K.
Actually GM Ahpo had tested and my understanding passed his 8th Dan examination under the Soo Bahk Do federation. But due to politics, GM Ahpo wasn't awarded an 8th Dan certificate. Long story short, my instructor was apporached to resolve the situation. The result was that GM Ahpo was promoted to 8th Dan in Tang Soo Do by KJN Kim.
Thanks,
Patrick K.
Chizikunbo
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Hi Patrick,
(just call me josh btw) GM Chung Il Kim (you are his student?) did indeed promote KJN Ahpo to 8th dan at the TSDMGK Nationals, in 2005. GM Kim was one of the few folks GM Ahpo would accept the certificate from. I believe he was promoted to 8th dan in 200 by GM Hwang Kee but was never awarded the certificate. In 2002 the Tang Soo Do Mi Guk Kwan Assoc. Inc. awarded GM Ahpo with a 9th dan in the Mi Guk Kwan system.
--Josh
Hi Josh,
I will make sure to address you as Josh in the future. I am just so used to calling people by their last names as a sign of respect. Yes, I am a student of KJN Kim Chung Il. By the way, he prefers to go by KJN C. I. Kim.
Thanks,
Patrick K.
zDom
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Not unique, but there aren't a whole lot of people who can do that.
I suspect that this ability to control the depth in force is possibly dim mak -- the ability to impart force into internal organs with little apparent damage at the surface.
But then, I suppose that is a subject for another thread
Chizikunbo
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Thanks, and I can appriciate that, but I really am just fine with Josh...
BTW, thanks for the info on the use of KJN for C.I. Kim...I will remember that for future reference as I hope to meet him at MGK nationals ;-)
I suspect that this ability to control the depth in force is possibly dim mak -- the ability to impart force into internal organs with little apparent damage at the surface.
But then, I suppose that is a subject for another thread
Good call ;-)
--josh
Last Fearner
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exile is correct in that a top board can affect this. It is also the reason that single board breaks fail sometimes when the student has broken before, or both boards fail in a two board break if the back board is the tough one. Grain alignment (as to what part of the tree a board is cut from) is one reason, knots in the wood can be a problem, and wood that is fresh with sap rather than dried.
Kacey is absolutely correct in that the consistent problem of breaking the back board is most likely due to improper extension, and follow through of a technique.
Multiple board and brick breaks always break the back (or bottom) board and brick first. There is no magical trick to that - - it's just physics. Could you imagine it any other way? Unless a board or brick was defective, the top one or middle one is not going to break and leave the others unbroken. A weak board or brick might crack or shatter under impact leaving sturdier ones intact, but if they are all of the same strength and integrity (without any flaw or special condition) the back one always breaks first!
Without spacers, the front boards are supported, and reinforced by the boards that are resting behind them. The power of a multiple break must be sufficient to carry through to the back board and snap it first. If the strike contains only the amount of force needed to do this, the front board will resist breaking, and it will not snap.
I have had this happen when breaking 5 or 6 boards where only the back one will break, or sometimes, 3 or more will break - leaving one or two in the front still intact. Not only do you need sufficient power in the technique to break both boards, but you must strike the surface while your leg (or arm) is still bent and having enough range to extend through and beyond the back of the last board.
To fix this problem, replace the board with a piece of paper, and have the student practice striking whatever is behind the target (If people are holding, put chest protectors on, and practice going through the paper to the chest guard. It is not just the impact on the surface that breaks multiple boards. That is what separates a beginner breaker from an advanced one (no insults intended). This is a test to see if the student is breaking properly, or just poking at the surface. Those who jab and retract can break one board by itself, or send enough force through to break the back board of two, but you must aim beyond the back board and be able to reach that far in order to continue the drive of your force through the board.
(That will be $500.00 please! :mst: ) :ultracool
CM D.J. Eisenhart
Hi Josh,
I hope you have the opportunity to meet with him. If not, then let me know. Perhaps, I will hook you up.
Thanks,
Patrick K.
Yes. This has happened to me and is not just disappointing and frustrating, but baffling. It really does help to think of the visual order (top/front first, lower ones later) as the opposite of the way the shock wave works destructively (lowest first, top ones later). Those novely office toys, with the row of balls hanging from strings, make LF's point nicely: swing the nearest ball to you like a pendulum so it strikes the one behind it, and what happens? The last one in the line swings up. The shock is transmitted elastically (or nearly so, the harder the material) until the energy involved takes the form of motion, affecting the last ball in the row.
This sounds right. Without spacers, you might break the back board (get the last hanging ball in the row to fly up) but you won't be able to break one or more of the boards in front (get the whole row of balls to fly up), if you aren't generating maximum force. Only when the bottom one breaks will there be `room' for the top ones to break...
Even so, $500 seems a bit steep... how about a wheelbarrowful of breaking boards??(actually, that might not be such a bargain at current prices... :uhohh
That or keep in mind that impact does not break the boards, shock does.
Here's an experiment that may help the visualization. Instead of breaking a board, try to break a pencil. Suspend a pencil between two thick books.
Find the center of the suspended pencil, and apply downward pressure from that center point. Increase the pressure until you start to hear the pencil break a bit (try not to break the pencil completely in half).
Once some of the pencil is broken, stop.
Where is the broken wood on the pencil? You will find that the breaks are on the bottom of the suspended pencil, not on the top where you were applying pressure.
Boards aren't much different than pencils, they're just bigger and need more skill to break.
Chizikunbo
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Hi Josh,
I hope you have the opportunity to meet with him. If not, then let me know. Perhaps, I will hook you up.
Thanks,
Patrick K.
Thanks!!! Ill remember that ;-)
take care,
--josh
Forget shock waves. Here's how it works....
Consider a board or brick in cross section.
When you strike it it bows out underneath the impact. The top is compressed. The bottom is stretched. Somewhere in the middle there's a neutral axis, but this isn't civil engineering class.
If you push it far enough the bottom of the board will start to break down. Fibers will separate or break apart. As this happens you will have more (force, jerk, thump, energy or several other physics terms) concentrated in a smaller cross section of the now-thinner board. The process will continue upwards until the board breaks.
If you have spacers between the boards you are essentially breaking each one in succession.
If there are no spacers between the boards you are doing something a little different (and much more difficult). The two boards can be considered one extra-thick board. When you strike the top board it bows out and causes the board beneath it to bow out as well. Since the bottom board will be pushed out further it will break first. In fact, the the top board will not have a chance to deform far enough to break until the bottom one is out of the way.
This is about the best my still-fevered brain can do right now. Does the explanation clear things up or confuse things further?
Consider a board or brick in cross section.
When you strike it it bows out underneath the impact. The top is compressed. The bottom is stretched. Somewhere in the middle there's a neutral axis, but this isn't civil engineering class.
If you push it far enough the bottom of the board will start to break down. Fibers will separate or break apart. As this happens you will have more (force, jerk, thump, energy or several other physics terms) concentrated in a smaller cross section of the now-thinner board. The process will continue upwards until the board breaks.
If you have spacers between the boards you are essentially breaking each one in succession.
If there are no spacers between the boards you are doing something a little different (and much more difficult). The two boards can be considered one extra-thick board. When you strike the top board it bows out and causes the board beneath it to bow out as well. Since the bottom board will be pushed out further it will break first. In fact, the the top board will not have a chance to deform far enough to break until the bottom one is out of the way.
This is about the best my still-fevered brain can do right now. Does the explanation clear things up or confuse things further?
I agree with most of what you said, but I will disagree with this one part (bolded). 1 2" thick board is much harder to break than 2 1" boards put together - for the reasons you've given. It is much harder to make a single, thicker board bow than several thinner boards put together, even if they are strapped together.
