Sunday, 30 June 2013

New Designers 2013

Spent the last week (or so) at New Designers in London (LaaaaahnDaaaaaahn, innit guv).

New Designers is an annual exhibition of work by graduates from colleges all over Britain.

Anyhow, it was absolutely amazing. It's generally considered rude to take pictures, but let me tell you some of the 3D design work was simply jaw dropping.

Here's some of my display anyway.

I had a few useful conversations, of which more shall be said later. The week was very useful and completely exhausting (as all trips to London inevitably are) and we're glad to be home. Now I'm off out back to cut my loom-wood down to size so I can get it into the house.

Sunday, 23 June 2013

Building a jack loom Part 1: Vague plans and messy diagrams

I've been thinking about it for a while to be fair.

What I'm thinking about is an 8 shaft folding jack loom. The interesting part comes when I point out that I'm going to build an electric dobby controller into the bottom of it so it operates from one pedal and a computer program.

So far I've been thinking and thinking and I'm basically roughly copying the kind of frame you'd find in a Siever's school or Baby wolf loom. Basically it's like an X that folds up on itself with the castle in the middle. Should be able to reduce it's depth from 3 feet to about 1 for storage.

I don't think it's really that difficult to design the loom frame, aside from building the beams and making the ratchets and so on, which I may just jigsaw out of thick MDF. I have most of the wood I need asides from some panelling and I need to buy some aluminium sheet to make the shaft dividers with and also to hold the shaft bodies together with.

The rising levers will probably be made from mdf 6mm panelling, perhaps with rollers or aluminium plating on the ends to stop it from wearing.

underneath the levers there'll be about 8" of space for the wires to go down before entering the selection box, which shall be controlled by servo motors (I have them from a previous project, I also have the programming for a 16 shaft controller nearly done already and the electronics are all laid out so I'll just have to fit them into the new frame).

Then I have to figure out the best way to set up the pedal, whether front or back levered, or if there's a way I could easily create an assisted lift, or even put in a wheel there.

If I was to use a wheel then there's be less wasted mechanical energy in lifting and dropping the shafts, but it's a little complicated. Of course the thing about a rotary mechanism is it could just turn and turn and raise and lower the shafts automatically if powered by a motor or a bicycle pedal which then offers the possibility for further automation of the mechanism, though it's probably troublesome to install automatic beating and weft insertion on a 2ft wide folding jack loom.

But you never know, as long as the frame was sturdy enough I don't see a problem, assuming I can make all the mechanical parts out of MDF. I'm convinced it's possible, with enough tinkering.

Maybe I'll just start with a pedal then try adding a wheel for shedding.

Anyway, I'm going to throw up my diagrams here. As you shall see, I am not trained in the art of the technical draftsman

 General side view and approximate dimensions. I may change my mind on the exact height
 More detailed calculations here, trying to figure out relationships between the height of the castle, where the bolts go and the length of the folding legs
 Building the depth of the castle, taking into account the wood and cladding for the shafts (which have to be square and rigid as well as smooth) and clearance and dividers (which will be made from doubled over aluminium plating)
 Figuring out the total weaving width, and then from there the exact width of the frame, taking into account washers and clearance space again. One arm will have to wider than the other, I think it should be the one that carries the beater and cloth beam, as the beater needs something wider than itself to pivot from. The warp beam can afford to be a little narrower than the cloth beam. So i think anyway.
 A double arm raising jack action. Perhaps unecessarily complicated, but it does look very effective.
 The shed. Dictated by the size of the heddles, the maximum shed depth is 6" at the shaft.
 Figuring out the height of the castle and how big the lifting zone needs to be. Everything is now in millimeteres. The lifting zone has to be the height of the shaft (heddles, plus generous clearance plus the shaft frame) plus the lifting height.

In order to reduce height and because i think it's pretty I've set it so the shafts will raise a couple inches out of the castle. I find that pleasing.
 The total space for the lifting mechanism (the jack action) which shall go under the shafts to push them up.

Also, a split lever jack action. Which is what I'm going with as it looks like it uses less space depth wise
 The split lever jack action in raised position. The action needs twice the lifting height, plus the width of the frame that holds the levers, and a little extra space for it's cords.

Then it needs a wee bit extra leeway before it enters the selection box, which I haven't designed yet.
That's the whole mechanism there. I may have made a mistake here, as I don't believe I need to leave any space between the fully extended jack action and the selection box there. I think I need the extra space between the box and the lifting pedal

In principle I see no reason why this system couldn't be simply automated with a continuously rotating wheel.

Monday, 10 June 2013

Tablet Weaving Lesson #1: Backstrap weaving a simple diamond motif

This is the first in a series of video and photo tutorials showing basic to advanced tablet-weaving concepts.

These lessons shall each build on the last and hopefully take the viewer from simple diamond patterns up to more complicated double face pattern weaving with finer yarns and eventually onto the heady heights of brocading and other fancy techniques (just as soon as I learn how to do them myself).

In this first lesson we'll learn the basic weaving steps involved in weaving a diamond pattern in the backstrap style.

This lesson is meant for someone who has purchased a ready-made warp from me. The next lesson shall detail how to design and make this warp oneself.

And we begin

This is the basic pattern we are making. The woven band is tied to my waist with another strap. I am holding a small stick shuttle in my right hand which contains the weft.

In front of me are the cards, each card has 4 warp threads going through it. The gap that you can see is called the shed, this is what the weft shall pass through. Each time we turn the cards we cause the warp ends (threads in weaving are called ends if they are of the warp and picks if they are of the weft) to twist around each other, this traps the weft in place.

The following steps I demonstrate are using a practiced hand. Initially when I was learning I often turned the cards using both hands. If you find this easier then please feel free to turn the cards and insert the weft anyway you feel comfortable.

First we need to move the cards up the warp. Place your thumb on top of the warp and your pinky finger below. Place your first finger in the back shed and use your two other fingers to hold the pack steady. In this way you can keep all the cards together when you move them so none of them turn in a funny way that they're not meant to.

Now push the cards up a bit. This gives you a bit more space to get the shuttle in. It's always nicer to have a decent working space for putting the shuttle in, rather than trying to squeeze it into a small space.

Now, get one hand into the shed and use that to pull through the shuttle. I do it this way as I find that if I just push the shuttle in unguided it sometimes catches on warp threads, which isn't good.

Then pull the shuttle through to insert the weft.

Leave a small loop of weft sticking out the side. The purpose of this is to allow you to finely control the width of the band. If we were to pull the weft all the way in upon insertion then the band would tend to become narrower and narrower. This is not so much of a great issue with a chunky band like this, where you're unlikely to notice a small difference of a few millimetres in the width of the band, but when one is weaving very fine threads and making detailed work later on it becomes very important to maintain consistency. If you like you can weave a small amount to find the perfect width for your band and then use a small marked stick or a measuring tape to measure the band every now and again and make sure you are not deviating from your desired width.

Now, to turn the cards, place your hand upon it like so . . 

. . . and roll them backwards . . . 

. . . a full 45 degrees.

This is called one turn. You will notice that I have placed my hands around the cards again in such a way that all cards are held in my hand simultaneously and they all move together. If you have smaller hands or are using more cards, you may find it more useful to turn the cards with two hands or to move them in groups. It's entirely up to what is comfortable with yourself.

Now we're ready for the next pick. Get your hand in front of the cards again . . .

. . . and push the pack backwards to make space.

Again, insert the weft . . .

Now we are ready to "tuck" the previous pick of weft. Hold the tucking side of the band with one hand and pull the weft from the other side with your other, taking care not to pull too tightly. Some designs may call for you to leave a small loop on the outside for artistic effect, but generally you don't want to weft to show too much.

Now the weft has been fully tucked.

And we beat the fell. The "fell" is the point at which the woven cloth or band meets the unwoven weft. The purposed of beating the fell is to push the previous pick of weft into position and to tighten up the woven face of the band. The strength of the beating determines the tightness of the pattern. I prefer a heavy beat as it's easier to maintain consistency and it allows you to get more pattern into a smaller space.

Something to consider when doing this is the nature of the yarn you're using for your warp. If, as is likely, you're learning to tablet weave for historical purposes, then you're likely to be using wool. Wool is very catchy, and if you simply try to push the shuttle down to the fell in the manner that I demonstrate in the following video, you're likely to cause yarns to snarl on each other. In this case it may be better to take the bottom and the top of the shed and pull them apart with your hands in order to separate the top and bottom layers of warp threads before you beat down the fell. This is less likely to be an issue using silk, cotton or acrylic, or for that matter nylon, which is my favourite material for practicing new TW techniques as it's fine, strong and nice and shiny.

And there you have it anyway, your second pick is in place, you have a wee loop sticking out the side and you're now ready to turn the cards again and continue weaving

Now, to observe all these steps in motion, see the following video.