Mecha Kumihimo

The other day I mentioned a steam-powered rope-braiding machine. And I got a lovely email from one of The Commentariat, with a link to a very cool Japanese rope-braiding artist who does amazing work. I immediately shared that link with all my rope-kinky friends, who are now all variously happy and envious.

Rope braiding machines are a completely different animal from rope twisting machines. If you search the intertubes for “rope making machine” you will most likely encounter a rope twister. With a rope twister you’re tightening the fibers against themselves so that they bind: rope. With a rope braider, you have a different problem – you need to move the ends of the threads between eachother, which means that you need bobbins on moving somethings that spin and move relative to eachother. So the basic rope braiding pattern looks like this:

If you’re interested in building your own machine, it’s complicated. Your spindles have to weave in and out so the ropes go between eachother, which means that the spindles are located in a race; they’re geared against eachother, and they’re guided by the race. Your drive system depends on the moving spindles engaging correctly with eachother and not jamming – especially if you’ve got power behind it.

You can buy rope braiding machines from India and China for not a huge amount of money. But expect to have headaches over importing them. This Indian-made rope braider has the takeoff on the bottom, and the bobbins at the top; probably a good design: what happens if a piece of the thread breaks and drops into the bobbin race? Sccrreeeeeee!!! That’s what happens.

why your round carbon fiber thing is so expensive [source]

why your round carbon fiber thing is so expensive [source]

This sort of spinner design is also how carbon fiber rod is made – beautiful stuff – and stainless steel braid for your hot rod engine or your water-cooled PC. Now, think about being in a room with fast-rotating bobbins carrying lots and lots of carbon fiber or stainless steel wire: what can go wrong? The worst things that can go wrong are horribly wrong, indeed!

I remember one climbing store I saw in Germany that had a rope braiding machine in the window – they would do your rope in custom colors. I bet it wasn’t cheap. Mountain climbing rope is kevlar core with nylon surrounding it (kevlar used to have problems with UV) and I imagine getting the tension right between the nylon and the kevlar was interesting – and has life-threatening implications if you don’t get it right.

So, here’s what one of the vintage (the one I saw was steam powered) machines looks like in action:

That’s a thing! I imagine that getting the tension in the bobbins is a concern. I imagine lubrication is a concern. I imagine finding spare parts is a concern. And I imagine that winding the bobbins is fun, too. Picture what an industrial-age factory full of these things would have looked and sounded like! (Workers in old cotton mills died horribly and often)

Now that you’ve seen the old machine, you can appreciate the beauty of the Japanese machine:

Notice how it’s making square braid; the machine appears to have a swappable plate that allows the weave and the pattern of bobbin movement to be changed. It’s a beautiful beautiful thing.

There’s more on braiding on this site [Kumihimo by sylvus tarn] Hand done! I’m so impressed!

And lastly, computerization turns up everywhere: if you have a braiding machine, and you can exactly vary the pattern and the tension, you can make shapes of varying dimensions in your weave. Why make sheets of carbon fiber and lay them up into an object, when you can just weave the object?

dividerHat tip to Commentariat triple agent sylvus tarm, who emailed me with the link to the kumihimo! [sylvus’ crafts are here – check ’em out!] I had no idea it was an art form in Japan, but – of course – there are so many applications for braided silk in Japanese culture, and they tend to take everything they do and turn it to “11.”  So of course it’d be high art. I won’t look at the tsuka-ito on the old swords in the museums quite the same way, now that I realize that it’s got to be hand-woven from silk thread on the older mountings. Aiee!

In case you’re not tired of braiding machines, here’s a Lego technik one:


  1. kestrel says

    Wow, those are amazing! I’m a braider and of course do it all by hand. I call this type of braiding, “braiding up” because if you do it by hand, you work the strings across the top of your fist (holding the finished part of the braid in your hand) and the braid slowly grows upwards. But you can also “braid down” where your strings start up high, you manipulate them, and instead of growing upwards the braid grows downwards. So, to me, Kumihimo and the types of braids that you see in the highlands of Peru and Chile in herding and dance slings are “braiding up” and the types of braids that you see used in cowboy gear are “braiding down”. (That is sure not official, it’s just the way I think of it, and helps me understand how I need to work to create that braid.)

    That would be amazing to have a machine, and would sure be fast, but for my application, doing it by hand is the only way to accomplish it. Horsehair just doesn’t come that long that you could wind it on a bobbin like that… :-)

    Fantastic work, sylvus tarm! Really enjoyed your site!

  2. says

    A hit-and-miss engine, what a classic. With machines like this, you’d get very good at making your own spare parts, or be in a good relationship with a foundry and an old fashioned machine shop. Oh and for lubrication, there will be a watchful engineer in stained overalls nearby with an oil can close to hand.
    OT I saw a video recently of a unique vintage racing car that had terminally cracked its engine block. With zero spare parts manuals or sources, the engine was stripped, digitally scanned and the block lovingly recreated in cast iron and reinstalled. A combination of old school skills and modern imaging can fix almost anything. I believe the casting patterns were 3D printed.

  3. says

    If you look on ebay for “maytag hit miss” there are beautiful retro-model vintage washing machine (!!) engines, in the $400 range. One of the neighbors up here uses one to drive a small generator when there are power outages; the thing has been working more or less flawlessly since the last ice age. You can also find lister diesel engines here, and those things are really wonderful wonderful wonderful.

    OT I saw a video recently of a unique vintage racing car that had terminally cracked its engine block. With zero spare parts manuals or sources, the engine was stripped, digitally scanned and the block lovingly recreated in cast iron and reinstalled. A combination of old school skills and modern imaging can fix almost anything. I believe the casting patterns were 3D printed.

    That’s amazing. I love that they can do that sort of thing now.

    I knew a guy who got rich doing software and got involved in a project to get a WWII tiger tank back in running condition. It turned out it was stuck in a ditch somewhere and had a blown transmission. So they kept a whole machine shop busy for a while custom cutting gears. The mind boggles. Nowadays I believe you’d make a 3d printed model, then make a mold from that, and form the part out of powdered steel. Adam Savage was talking about some of the stuff he’s seeing in the tooling pipeline – 3D printers that are intended to go directly to manufacturing without an intermediate step. So you’d print the engine block, put the pistons in, bolt the heads and crankshaft in, and off you go. They are doing ridiculous tolerances and surfaces that machine shops can’t even think about.

  4. komarov says

    Well, I hadn’t seen that before, so thanks. The Kumihimo machine looks strangely insectile to me. A mechanised anthill, perhaps, or just one creature with a lot of mandibles.

  5. says

    “do see do your corner, now loop around your partner and form a knot!”
    Actually, I believe morris dancers make a braid around a maypole. So you could probably have rope-making reenactors… Powered by beer.

    Now I am curious about the relationship between square dancing and morris dancing. But not very curious.

  6. invivoMark says

    Climbing rope is not kevlar. It is nylon. Kevlar would make a terrible dynamic rope (i.e., stretchy), so if you took a fall, you could seriously injure yourself!

    There are some static ropes for hauling equipment that use kevlar, but there’s no reason to use something so fancy.

  7. says

    I may be confused; I guess it’s nautical rope that’s nylon over kevlar (that’d be an application where stretching is undesirable?) Anyhow, it was a climbing store, and the rope was a braided layer over a slightly twisted core.

  8. rejiquar says

    RE braiding up or down (kestrel, 8:15)

    Kumihimo is just the Japanese word for braiding. Before the foam disks became popular, probably 98% of all braids were made on the marudai (round stand) and braided `down’ —though you can go either way. Braiding `up’ is kind of a pain, because then the braid has to be suspended somehow from above.

    The kakudai, or square stand, sometimes come with a method for suspending a braid, as well these inserts around which the braid is formed, which requires the braid go up to get out of the way. This allows for some fun effects, like ducktail (kamogawa) which is roughly analogous to wraps in macrame and is nearly impossible to do without that insert holding the point of braiding in place while you do the wraps:

    That said, aside from some very clumsy efforts at kara uchi, I’ve never managed to make any kind of round braid with just my hands: I just can’t seem to wrap my head around the sequence of moves without the kagami/mirror to keep the strands organized for me.

  9. A. Noyd says

    Kumihimo is an important plot element in the anime movie Your Name (Kimi no Na wa). Apparently it’s in theaters in the US now, though the release is limited.

  10. kestrel says

    @rejiquar: I am sorry I was not clear…. when you braid on a marudai, the braid goes up… as in, that’s how you make it longer. You are manipulating the ends ON TOP of the actual braid, and so your braid is growing up to the sky. That is what I mean by braiding up. Braiding down, which is what people are doing when they braid their hair, but it’s also how things like romal reins are braided, goes the opposite way. You affix your ends somewhere up above your hands, and commence to braid down toward the earth. Your braid is manipulated at the part closest to the ground, and grows down to the ground. That’s what I mean by braiding down.

    Your braiding is beautiful! Here is a pic where I have the braid set up and I am braiding *down* to the ground… you can see I started it at the top, and the braid grows down to the ground: This is a 25-strand double flat braid. It is of course made of horsehair.

  11. Reginald Selkirk says

    Fascinating. Using multiple colors makes for a better video. The Lego machine (last video) seems to be using a slightly different principle than the gas-powered machine (first video) in that a fork was moving the bobbins from one rotor to another (sorry for not knowing the lingo), whereas in the gas-powered machine I believe the bobbins were following a track. The Lego machine could use some tuning as far as keeping proper tension.

  12. says

    Reginald Selkirk@#15:
    I have another posting on braiding machines queued to drop (I’m going to be out of town speaking at a conference the next few days) that’s got better illustrations of how the machine’s bobbin races work.

    The lego machine is doing a more typical crossover pattern with the forks – and, as you can see – it doesn’t run very fast.