Braid modelling

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Jan 292013
 

I have thought for a while it would be really cool to be able to model an new braid on the computer. My idea was that I would put in the marudai moves of the braid I wanted to “make” and my program would figure out how the threads moved and what the braid looked like.

Well, I never got around to it; there were always too many other things that seemed more urgent, and I have to admit I wasn’t sure how I would go about it.

Murray is by far the better programmer of the two of us – he has been earning good money doing that for the last 20 years, until a change in the company he worked for meant that we had the opportunity to both try working on Craft Design Online for a while. Having got Pattern Grid to a point he was happy with last year, then spent some time in the run up to Christmas tweaking things on it, he needed a new project. So he decided to look at 3-d modelling in javascript.

At the moment he’s got something that is getting quite usable. You can move threads around a marudai drawing and once you have put all the move in, tell it how many times to repeat the moves and your braid will be drawn. It works better in Chrome than Firefox – Chrome is able to use the graphics card which improves the image processing. It needs a reasonably powerful computer. We haven’t tested it on an iPod or mobile phone – we think it might work, but very slowly. And it needs to be made easier to use  – but that should come quite soon.

Computer generated diagram of braided tubesComputer generated diagram of braided tubes

I was quite impressed at the 24-thread mitake braids it generated. Just like the real braid, as you make it the threads are quite loose at the top, but they gradually get pulled in tighter. The threads are modelled as tubes, so you don’t see the flattening of a real thread.

It’s not going to totally replace the need to test braid before starting an important project, but it certainly gives a good idea of how a braid will turn out.


Takadai 2

 takadai  Comments Off on Takadai 2
Jan 082013
 

For Christmas, I got a takadai!

The original bamboo one didn’t last long. It was too flimsy to move anywhere, and too bulky to be left where it was (our kitchen/dining room). It was enough to get a feel for using one as well as some idea of sizing and practicalities and a good starting point for building our own.

Custom built takadai

The new takadai has the same rails, and a softwood frame. Joints have been made with  dowel bolts, insert nuts and dowel nuts so that it can be taken apart repeatedly without damaging the wood. Places where threads/braid slide against the takadai are hardwood or bamboo.

We have made the top bar of the torii a feature of the takadai. My husband found a piece of large diameter bamboo at a local garden centre/DIY store, and a piece of that has been used for the top of the torii. Sanded, it makes a lovely rounded and smooth feature which the braid goes over. Also, we have put the warp roller into the torii. Even though this is different to those made using Rodrick Owen’s plans, it seems to work, and I think I have seen pictures of other takadai like this. A ratchet mechanism stops the bar from slipping rather than the traditional chopstick as brake – the ratchet works well, and is far better than the previous version made from string. Unfortunately I turned it the wrong way first time I adjusted the braid position, but a bit of glue and it is fine now.

I also have 2 swords, both made from the same piece of bamboo the top of the torii came from. The first one, presented with the takadai on Xmas day, was too long. It was awkward to use, so I have a second, shorter one. I love the look and feel of the bamboo, it is very light, and the slight curve in the handle is nice. Perhaps the longer one will be useful if I ever learn more about the ayatakedai.

The koma are the same as before – bamboo with dowel pegs. Being bamboo, there is some variation in size between koma, but this does not seem to have caused any difficulties. However, I have discovered a slight problem with them – if I have empty koma at the back of the rails, sometimes they will push up and pop out. This has happened when I have been setting up and finishing with a raddle across the rails, and also if I have an empty one in place to change the angle of the threads at point of braid. Not helpful! We have found that attaching a block of wood at the end of the rails prevents this, so once I have taken my current braid off, these will be permanently fixed in place.

The next problem to tackle is tama. I had plenty of plastic pots, filled mostly with 1 and 2p coins, for using with the marudai, but now I need more and heavier. We have decided to try making our own, but shaping that number of tama out of wood is going to be hard work… Maybe there is an alternative… We have a couple of ideas we are working on – although weight consistency is not there yet, the shape is better as I find the pots slip through the slipping hitch if I am not careful enough with it.

This brings me to a comment on the torii bar. At the moment it sticks out beyond the outer rail on either side. We decided to leave it like this until I have had a chance to use the takadai and decide if I am happy with the positioning of the rails. The experimental tama I have is larger than the pots, and may mean I need a wider gap between the inner and outer arms, but this is something we are still working on. I also have this fancy idea I might want a 3rd pair of arms. I have seen someone with a takadai with 3 arms on each side on Youtube (around 2:20 into this video) – I have no idea how it is used, but maybe one day…?