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<< 5 / 2011 7 / 2011 >>

Things to take away from today's kendo class

2011-06-25 13:46:00

It's starting to become a theme, but:

Today's class felt GREAT! After our usual warming up (though again without running laps) we did at least an hour of waza keiko, practicing all of our basic techniques. The more advances students finished off learning different counter attacks to deal with a fast men strike. In the mean time, Hugo and I kept on repeating the basic drills: big men, fast men, kote-men, big men. To end it all of, the students in bogu then did a rotating sogo renshu, where each student was in turn attacked by the eight others to practice their new counter attacks. 

The final twenty minutes of class were spent on jigeiko, where all students were free to practice with one another and with the teachers. During the waza keiko and during the jigeiko I spent about ten minutes with sensei Ton practicing the fast men strike, something that I struggle horribly with. The proper form is to:

  1. Step in.
  2. Step in and thrust straight for the face.
  3. Sweep up the kensen and strike. 

The problem being that I fail to do a straight thrust for the face. I kept on "shoveling", meaning that I lower my left hand (tipping the shinai upwards) followed by moving my arms upwards, to slap the shinai down again. To get rid of this annoyance Ton had me do something unusual: practice tsuki thrusting (short video) on him.

That got the message across, though Ton then pointed out a new flaw in my form: when doing a thrust I habitually do a very small pull backwards on my sword, which is a total and dead giveaway of what I'm going to do. The suggested training method Ton gave me: stand in front of a mirror, hold your hands at normal kamae height, then thrust at the throat of your mirror image. Man! I'd really love to have that training dummy by now :D

During the jigeiko part of class mr. Waarheid (another visiting student) suggested that we do some uchikomi geiko, where he'd make openings for me to strike. When practicing fast kote-men-do he pointed out that I was screwing up maai, by stepping in waaaay too much for each consecutive strike. 

What a great class! I feel awesome and I've learned so much today :)


Ah yes! More things... During jigeiko I had to bow out for a few minutes to get my heart rate to drop. Five rounds of kirikaeshi, followed by five double rounds of men, men, kote-men, men got my heart pounding and sadly I couldn't bring myself to push through. So I sat out one round of bouts and then jumped in again. And again, Ton reminded me that my kamae is too tense. I also twist my wrists to the inside a little too much, which limits my maneuverability. tags: , ,

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Kendo project: shinai carrier (2)

2011-06-25 13:24:00

A bag to carry shinai

For the past three nights, Martijn and myself have been working on making our shinai carriers. On Wednesday we went to get the materials for the sturdy and waterproof interior. We even got the basic tube finished by then.

Thursday and Friday night were spent on making a cloth exterior, which includes a side pocket for bits and pieces (mostly tsuba and tsubadome). By Thursday at midnight my bag was covered in cloth and only required a bottom piece to finish it off. Yesterday was spent on dressings Martijn's tube and in painting kanji on his bag. 

The designs:

Both bags still "require" a covering for the top, but for now I'm happy with the result: two sharp looking and perfectly safe carrying bags for three shinai and a bokken each. tags: , ,

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Kendo project: shinai carrier

2011-06-22 22:40:00

PVC tube shinai carrier

Inspired by Kristin's lovely naginata carrier project, Martijn and I have started our own spin-off: the rock solid and water tight shinai case (announced earlier this week).

This evening we trotted to the local DIY store to get four meters of PVC tubing (the most economical choice) and all the required trimmings. The full shopping list came in at:

All in all the bill for that comes in somewhere around 15 euros per shinai case and we still have tubing left for a third one. Not bad for starters. For Martijn's case he added a few euros more for the strap and trimmings, while I used the strap and materials from a denim bag of mine that was worn out. 

We could've actually kept the costs down a little more by going with either 100mm or 75mm diameter tubing. Our 110mm cases are large enough to fit no less than three shinai and a bokken! o_O Most kendoka carry either 1+1 or 2+1 so our cases are "spacious" to say the least.

For now the cases might not look like much (they really are just PVC tubes with straps), but the next phase of the project will be to find a nice way to dress the cases up a little. I'll probably be going with some strong denim to match the strap, while Martijn was looking for something a bit more out of the ordinary. All in all, there's a nice sewing project coming up! tags: , ,

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Time to break out the tools and get creative!

2011-06-19 10:07:00

building a kendo dummy

Who'd have thought that training a sport would also lead to creative tendencies? You may remember that I kind of, sort of damaged our fence a few months ago, looking for a target to practice men strikes. Since then I haven't found any real alternatives, leading both Martijn and I to search for a frame or a dummy of sorts. A quick search turned up simple practice dummies such as this one and this one. Both look fine and shouldn't be too hard to build. 

However, instead I would love to build the dummy pictured on the left. It's based on free instructions by Best Kendo, who provide full plans and designs to build this kendo practice dummy. The good part about this dummy: all three valid striking targets (men, kote and do) are available and there's even an option for the dummy to hold a shinai for added realism. It may be a complicated design to put together, but it looks great!

One thing I would like to do differently from the Best Kendo design, is to construct the dummy in such a way that it can be dismantled for storage or transport. This would require a minimal change to the design of the arm (just use a different screw/bolt combo), though the foot would be quite different. Instead of glueing and screwing the body to the base I would use another axle screw/bolt. Because this might compromise the strength of the structure, it might be wise to add a diagonal leg which gets connected with a similar peg. 

Another project that I'm looking forward to is making a weather proof case for my shinai and boken. My ideas for the design are inspired by a homemade naginata case project by Kristin. For my shinai case I'll be getting a PVC tube which, like Kristin, I will be covering in a nice looking fabric. Unlike Kristin i won't be attaching the straps to the fabric, but instead I'll use rain pipe fasteners which are usually used to connect a PVC tube to the side of a house. tags: , ,

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Kendo class? More like kendo clinic!

2011-06-18 13:04:00

Like last week, today's class was tiny! Aside from Ton and Kris, there were four of us out of bogu, two young kids in bogu and maybe two other adults in armor. So that made for a very skewed class with three 2nd dan teachers (actually, I don't really know Raoul's grade, he could very well be higher!), one 1st dan student and the rest of us just lowly mu-dansha. Basically there was one teacher per two students. That doesn't make for class anymore, it's a friggin' clinic! Seriously, had this been golf we'd have paid through the nose for a class like this! In all I had at least fifteen minutes of personal attention from Kris! 

Anyway. Just like last week:

It's nice to see some improvements though! After my very first lesson in January I wrote: "I can only dream of ever becoming as fast as some of these folks! One fellow I practiced with would be able to get in five to seven blows for every one of mine. The light footedness! Amazing!". What I wrote then was after learning haya suburi (go watch the linked video!). While I'm nowhere near the speed and souplesse of our teachers yet, I am very happy that I can keep up with my fellow students. ^_^ tags: , ,

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Analyzing my men strike

2011-06-14 22:44:00

As I wrote earlier, last weekend I learned that many aspects of my kendo suck. As my teachers suggested I set up a camera to record about fifteen minutes worth of shomen strikes, both with and without fumikomi

With my layman's eyes I notice the following:

There's plenty more to learn, so I'll be rewatching that clip a few times more. Below is just a small excerpt, so folks can make fun of me :P tags: , ,

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Well, that was hard work!

2011-06-11 12:54:00

Again, like a few weeks ago, we had a rather small group at Renshinjuku in Almere. While a low attendance does affect the atmosphere negatively (nobody's on edge) it also has an upside: everyone can get the undivided attention of sensei and the sempai. And today I learnt that many of the things I've been doing really aren't that good, but so far they've gone unaddressed.

Hillen noticed two things, one of which I've stupidly forgotten :( 

Kris really was very dedicated and noticed a boatload of things:

I didn't work with Ton very much today, but during uchi-geiko it was obvious that:

There was more, but sadly it doesn't come to mind just yet. I'll try to remember later...

Both Kris and Ton suggested getting a third-person's view of my suburi. Either by using a mirror or a camera. Marli had also suggested the same a few weeks ago. I'd better set up the mini tripod I have, so I can film myself. Worked when I was learning golf swings, so it'll work here as well. 

I spoke with Martijn, my study-buddy you might say, on the way home and I've decided that I need to up my running schedule to build more endurance. I don't know if it's the heat in the dojo today, if I'm just in a rut or whether I just suck, but today's class wore me out. I haven't sweat as much as this before! My keiko-gi and undershirt were drenched! I was already panting quite heavily after the laps of warming up footwork and I couldn't hold my post-striking position that long either (while the teachers were evaluating us). 

So. Not necessarily more, but longer running! And I really need to stick to my at-home suburi schedule! tags: , ,

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Locking the BoKS database for fun and profit

2011-06-07 00:01:00

If your BoKS master server ever inexplicably grinds to a halt, blocking all suexec and remote logins, just do a ps -ef to check if there's anybody running a dumpbase. Then pray that you can contact this person, or that there's still someone with a root shell on the server...

A running dumpbase process keeps a read/write lock on the BoKS database until it has dumped all the requested content. If you have a sizeable database a full dump can take half a minute or more. That's not awful and it won't affect your daily operations too much, but it should still be kept to a minimum.

But what if? What if someone decides to run dumpbase and then pipe it through something like more?

The standard buffer size for a pipe is roughly 64kB (some Unices might differ). This means that dumpbase will not finish running until you've either ^C-ed the command, or until you've more-ed through all of the pages. Thus the easiest way to completely lock your master server, is to more a dumpbase and then go get yourself a cup of coffee. Because not even root will be able to login on the console while the dumpbase is active. tags: , ,

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BoKS: registering SSH hostkeys in one blow

2011-06-07 00:00:00

Last weekend we upgraded our laster BoKS v6.0.3 server to 6.5, which presented us with a few interesting challenges. More about those later. But first! SSH host keys!

Per BoKS v6.5 the SSH daemon/client software will automatically verify that the SSH hostkey of the server you're connecting to matches the one listed in the BoKS database. If you're unprepared for this new feature, then you could be caught unawares with a situation where SSH warns you about a man-in-the-middle attack, despite your personal ~/.ssh/known_hosts file being empty.

To prevent this from happening we ran a simple two-liner right after performing the upgrade. The script below (if you can even call it that) will tell all the BoKS client systems in your domain to set their SSH hostkey in the database to its current key.

for HOST in $(sx hostadm -Sl | grep UNIXBOKS | awk '{print $1}')
cadm -s "ssh_keyreg -w -f /etc/opt/boksm/ssh/" -h $HOST
sleep 3

Of course you shouldn't run this script willy-nilly, but only at times where you know the current hostkeys to be correct :)

Once the FOR-loop has finished you will notice that the fields SSHHOSTKEY and SSHHOSTKEYTYPE in table 6 of the BoKS database will now contain values for each registered client. tags: , ,

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A few lessons from private kendo practice

2011-06-02 21:47:00

Tonight's practice with Martijn wasn't as serious as it could've been. We were a slight bit hurried, I'm nursing a cold, he'd sprained his back and we were giggly. Oh well, as long as we keep that out of the dojo it's fine ~_^

A few things I'm taking away from tonight:

Speaking of my personal training schedule, right now I try to do the following once or twice a week (aside from my sessions with Martijn and the Saturday morning in the dojo). This list actually matches the warming up suburi we do at the dojo, but ups the amounts quite a lot. tags: , ,

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Planning our trip to Japan

2011-06-01 12:45:00

The syudoukan dojo

In a few months the Sluyter family will travel to Japan for three weeks of holiday. Together with our good friends Kaijuu and Michel we'll stick around the Kyushu island for a week and hang around the Kansai area (Osaka) for another two weeks. It'll be nice to go back to Japan, especially Kansai.

In preparation for our trip I've already started expanding the Google Map for Shiranai Travel with all manner of interesting sights. Most of these will be centered around Kyushu, Hiroshima, Kobe, Osaka and Kyoto because we're temporarily avoiding going further east what with the whole Fukushima deal. I mean, we don't expect anything to be wrong with Tokyo and so forth, but we can always leave those areas for another visit.

One thing I will put on my "must do" list involves kendo (sorry honey!). I've recently learned that there are two excellent dojo right in the vicinity of our appartment building in Tanimachi Yon-chome. What's more, the Syudoukan dojo (pictured left) is actually on the Osaka-jo (castle) grounds! Both dojo welcome foreign visitors, so how can I pass up an opportunity like that?! Judging by the map I was actually pretty close to the Syudoukan dojo when we visited the gardens on New Year's night. The other dojo, Yoseikai, is a short trip away by subway and is home to one of the editors of the Kenshi247 website. tags: , ,

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Understanding the meaning of kendo kata

2011-06-01 07:05:00

A few weeks ago I'd found a few interesting articles about the meaning of kendo kata, mostly focusing on kata #1 through #3. The other day I was practicing kata with a visiting kendoka Raoul, from Amstelveen, and he was teaching me kata #3. While going through the motions I failed to grasp the riai (theory or reason) behind a certain movement and the both of us couldn't figure it out on the spot.

The question I had was: "What is it that motivates uchidachi (teacher/attacker) to drop his sword after already successfully parrying two of shidachi's (student/defender) thrusts?"

Now, thanks to the earlier reading I already knew that in kata 3, shidachi has no intention whatsoever of killing or hurting uchidachi, meaning that the two thrusts (or actually one thrust and one push) weren't parried to begin with. But again, why would uchidachi give up and simply lower his sword?

Sometime this week I realized what could be the answer: the seme (willpower) of shidachi completely supresses uchidachi's will to attack and uchidachi has realized that he's lost. Uchidachi is being backed against the wall, so to speak. After some more reading I've found materials that seem to support my theory, so I wasn't too far off :)

This is one of the aspects why I love kendo: figuring out puzzles is part of the kenshi's learning process. tags: , ,

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