Cutting Tatami

This Forum is a place for students of swordsmanship to ask advice from moderators Paul Champagne & Scott M. Rodell on how to practice test cutting in a manner consistent with how swords were historically used in combat. Readers use this Forum at their own risk.

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Linda Heenan
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Cutting Tatami

Post by Linda Heenan » Sun Aug 01, 2010 9:06 pm

I understand that bamboo was a traditional target for cutting training because it simulated bone, and that tatami was used to simulate muscle. If tatami is wrapped around bamboo, you have a simulated limb. Neither bamboo nor tatami have been easy to obtain in Australia.

In August 2010, a new company is opening that sells Mugen Dachi tatami omote http://www.ozitatami.com.au/index.htm . Both Japanese and Chinese swordsmen in Australia are happy about this. I've been promised 5 free tatami mats because I've advertised the fledgeling company on my website. This is good news and it will be useful to add this to my cutting training. I'm a bit short on knowledge though, having never seen it done except on Youtube. If anyone with experience in cutting mats has helpful information, I'd love to hear it. I'll write the results of my own first attempts and observations, later in August.
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Re: Cutting Tatami

Post by KyleyHarris » Sun Aug 01, 2010 9:59 pm

I'm in the same boat that they are just too expensive to warrant use day to day. There is one sword seller here that charges $15NZ per mat.. for 3 seconds of testing it seems too much.

I'll be interested to see what cost they will sell and ship to New Zealand for.

I've personally not used the mats but from what I've seen.. if they are soaked properly they are not difficult to cut. I would imagine that as long as you are not trying to Overcut them through force then your blade will probably just sail through them..

Look forward to hearing about it.

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Re: Cutting Tatami

Post by Linda Heenan » Mon Aug 02, 2010 12:08 am

For a start, there are some good techniques captured on the test cutting video. It's probably somewhere on this page but i couldn't see it, so I've linked to it on my test cutting page, here http://www.chinese-swords-guide.com/sword-cutting.html
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Re: Cutting Tatami

Post by KyleyHarris » Mon Aug 02, 2010 1:11 am

I just finished making a sword last week, so I went out and chopped a good bit of bamboo this weekend to test it out. I'll probably order some mats from this site because they say they are the proper quality test cutting mats. its worth trying it out at least one time or 2 ;) I made the blade out of D2 tool steel for its edge holding properties and stainresistance. I have to say.. its great having a blade that will slice and dice lemons and other stuff without rusting or forming a patina quickly. very easy to maintain.

I emailed the company to get a price. Thanks for posting about it

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Re: Cutting Tatami

Post by Linda Heenan » Mon Aug 02, 2010 11:22 pm

While preparing for tatami cutting, I'm doing some research. There are four main grades of tatami. It's actually a type of reed. The two thickest types are really good for floors but not great for cutting. Omote means the tatami is used as a final covering for a rice straw floor. If you buy used tatami, you might get lots of dirt mixed in from it being walked on. This could scratch your sword. Tight stitching is good because it makes for a cleaner cut. Mats with loose stitching have a tendency to bending. Some people cut with beach mats because they are cheap but it still takes 3-4 of them to equal one good quality tatami omote mat.

Tatami should be rolled before it is soaked. The darker green it is, the less soaking time, with a minimum of 4 hours and probably closer to 12 hours. Up to 30 hours is really good but most people can't be without their bathtub for so long :D . It's easier to roll correctly if you roll it around a dowel. Make sure the roll is very tight. Tuck the last part of the tatami inside by rolling it back on top of itself before finishing the roll (no single edges). Tie it in a number of places down the length of the roll. This sounds just like making one of our kid's padded swords. Remove the dowel when you have finished unless you're fairly advanced. If not, you might risk damage to your sword.

As with any cutting, there will some residue on your sword. It's a good idea to have an oiled cloth handy and wipe down the blade with it in between each cut, then do a thorough cleaning afterwards.

Okay, who has a good pattern for a cutting stand?
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Re: Cutting Tatami

Post by KyleyHarris » Mon Aug 02, 2010 11:36 pm

This style of stand is the simplest and cheapest to make;

http://www.bugei.com/images/Cutting_Stand_single.jpg

It requires about $20 of weatherproof 4"x4" wood.. (10cm Square) Which you cut into 5 lengths. 4 identical feet and the stand at the height you require. You then Drill holes to lock the feet on, and a 1" hole for a dowel peg you can remove incase of damage.

I can make you some instructions later.. Bugei had a PDF somewhere.

The site selling the mats has a basic PDF here

http://www.tameshigiri.com/make_a_stand.html

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Re: Cutting Tatami

Post by Linda Heenan » Tue Aug 03, 2010 1:03 am

My computer is refusing to open pdfs at the moment. I've made a stand like this before, so the foot structure is familiar. For others reading this thread in the future, clear instructions are a good idea. What size of sharpened dowel should be slipped inside the hole?
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Re: Cutting Tatami

Post by KyleyHarris » Tue Aug 03, 2010 1:15 am

The Dowel size really depends on what you are sticking into it. If you are going to be putting babmoo inside a matt then the dowel needs to fit in there.

I am guessing 2cm to 1" is a good size. Thats what ive used in the past. On a tight rolled matt it will push in tightly and hold it up. with the bamboo you want the dowel long enough to support the matt without wobbling.

here is a JPG version of the pdf
target_stand.jpg
target_stand.jpg (184.22KiB)Viewed 23939 times

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Re: Cutting Tatami

Post by Scott M. Rodell » Wed Sep 15, 2010 2:57 pm

KyleyHarris wrote:... personally not used the mats but from what I've seen.. if they are soaked properly they are not difficult to cut. I... imagine that as long as you are not trying to Over cut them through force then your blade will probably just sail through them...
Tatami (rice straw mats) can be quite difficult to cut, or rather easy, it's all a matter of how long they are soaked. Also, if they are soaked in hot warm instead of cold, they will be softer still. But in any case, don't expect to just sail thru mats. In respect to how long to soak them, 5 to 7 hours is a good rule of thumb for a cut-able yet reasonably challenging target, especially if you wrap the mat around a 1 1/2" diameter bamboo stalk (using a thinner stalk may just result in the bamboo snapping in stead of your cutting thru the target). Generally speaking, mats aer left to dry about have as long as they soaked before cutting. The sooner you cut them after soaking, the easier they will be to cut. (if you see a cutting demo where water sprays from the target, you know it was a very easy target to get thru).

Concerning mats from your local supplier, your are going to have to try soaking then for different periods of time to find what is right for them as mat quality varies from dealer to dealer.

Cutting mats can seem expensive, but they are excellent targets that can be used to practice numerous cuts on. The thing is to remember to cut small pieces off, not just cutting the target right at the center with the first blow.

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Re: Cutting Tatami

Post by Linda Heenan » Wed Sep 15, 2010 3:40 pm

Thanks, Laoshi. My mats have arrived. David and I will cut them when he comes up for a weekend of training on the 24th and 25th. We'll take pictures of the whole process and hopefully get some good ones to add to this discussion.
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Re: Cutting Tatami

Post by KyleyHarris » Wed Sep 15, 2010 8:11 pm

I'm looking forward to your opinion of the mats before I consider getting any.. The supplier is trying to find someone to do a bulk purchase in NZ, and distribute here because of the high shipping costs.

One thing I wonder is.. how are people soaking the mats.. If you dont have a Bathtub.. what else will they fit in :)

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Re: Cutting Tatami

Post by KyleyHarris » Wed Sep 15, 2010 8:28 pm

One Other Thought..

This is a single cut video I recorded testing a sword I made recently. its primarily a heavy convex blade similar to a Japanese sword with heavy convex.
Primarily the reason I'd like to share this with you is the opinions on Cardboard as a cutting medium..

This is standard Roll Cardboard packing, which is very cheap. that roll cost about $3NZ.. $2USD.. When Tightly rolled it seems to offer a lot of resistance to cutting. especially if the technique is not good. The first cut I did was terrible. I was more worried about hitting a wall. the 2nd cut (in video) I felt comfortable with the cut I could make in the space, and it went clean through, but with fair resistance.

I'd appreciate someone with matt cutting to try this and offer a comparison in the qualities.. Cardboard is readily available and very cheap.

http://www.youtube.com/watch?v=GOVjPQvO8EA



On a side note:- I made the sword out of D2 steel, at 54RC. I have done extensive testing and its not only stronger than anything I'd ever require, the stainresistance is incredibly good with no patina or rust even after fruit and citrus. at only 54RC this edge holds longer than many other blades I've tested at much higher RC ratings. Its a very expensive steel to work with. but the results are pleasing.

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Re: Cutting Tatami

Post by Scott M. Rodell » Thu Sep 16, 2010 7:18 am

KyleyHarris wrote:... how are people soaking the mats.. If you dont have a Bathtub.. what else will they fit in :)
Depending on how tall they are, you can use a large, industrial size plastic garbage can, or a blow up baby pool. Contrary to the "standard" method, you can soak them unrolled, that is how I do them. Then I wrap the mats around bamboo stalks right after pulling them out of the tub & leave them to dry.

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Re: Cutting Tatami

Post by Linda Heenan » Fri Sep 24, 2010 7:15 pm

I soaked the tatami unrolled, in the bath, overnight. It was then left to drain outside for 4 hours. We do not have bamboo, so I used branches off a fruit tree. One long mat was rolled around the branch. Next time I will make sure the mat is neat at the bottom.

Image

The mat was tied with string in several places so that it would not unroll during multiple cuts.

Image

We used quite thick branches since they are supposed to simulate bone and apple is not as rigid as bamboo.

Image

More in the next post.....

We decided to use the stand pictured below to hold the branch more tightly.

Image
Last edited by Linda Heenan on Fri Sep 24, 2010 8:00 pm, edited 1 time in total.
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Re: Cutting Tatami

Post by Linda Heenan » Fri Sep 24, 2010 7:26 pm

This was my first cut. I've never done it before or even watched anyone doing it, except on Youtube, so it was difficult to judge how much power to put into the swing. The first cut went through one side of the mat and through the branch.

Image

Another cut from the other side took the piece of tatami right off.

Image

It took me a few tries to work out how to go right through the mat and still maintain control of the cut.

Image

I am glad of all the practise on softer targets, constantly checking edge angle, etc. All this cutting was only done on the first mat. This afternoon, the Canberra boys will be up and one of them is up to cutting at this level. He's done lots of training in Japanese swordsmanship. I'll try to take some more photos then. This last one is a jian cut. I tried dao as well but seem to have much better control of my jian. It was easier to cut with. I suppose that means going right back to lots of hours of practise on dao basic cuts.

Image
Last edited by Linda Heenan on Sun Sep 26, 2010 5:13 am, edited 1 time in total.
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