Studio Contrechoc

design & textile & technology entries

Category Archives: knitting

Yellow Spiral Knitting

Double bed knitting, with words of 5 letters.

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2016 Swatch Exchange

For the swatch exchange, i made “Tiny Knittings”. We have to make 25 items, and found a way to make 25 different small knittings. Inside is a simple battery holder, printed on my 3D printer, with a RGB LED and ATtiny85 – smd.  This gives an alternating color.

http://etextile-summercamp.org/swatch-exchange/tiny-knittings/

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Cuvée – Summercamp 2016

E-textile presentation at Paillard, Poncé-sur-le-Loir, France

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A laser lit scarf, the light playing a game on the knitted surface.

Alien Socks

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Preparing a start up in case of ALIENS wanting to walk over the surface of the Earth. Hopefully they only have one leg…because i knit not in pairs.

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Data knittings

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Model: Jasna Rokegem
 

 

KH-940 and Teensy 3.1

The experience with the knitic board as a shield on an Arduino Due for connecting the machine knitter KH-940 with a laptop was not very positive. The board is very fragile. Connecting and deconnecting making it needing constant repair.

After the e-textile summercamp a week was spent on making a new board, connecting the ULN2803’s and programming the Teensy 3.1.

The Teensy 3.1 microcontroller has enough pin’s, it is small and cheap.

Because the Teensy is running at another speed, 24Mhz, the delay’s between the Serial command sent from the laptop to the Teensy had to be altered.

With the program code of the older board (already reprogrammed to reduce all unneccessary communications) flashed to the Teensy not only whole tours/lines were not read accurately, also single pixels inside a tour:

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The mistakes in communication in red, the red borderline below indicates the mistakes in lines.

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The mistakes in lines are removed, but inside the line, there are still mistakes in pixels.

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Making delays between Serial asking the laptop for data and receiving the data larger, the picture is received without mistakes.

The board connecting the ULN2803’s with the Teensy had to be adapted too, because the Teensy is working at 3.3V while the sensors of the KH-940 require 5V. This 5V is taken from the KH-940. The Teensy runs on the USB. Also the Teensy is not resetting if Processing is started, like it does witht he Arduino. So the initialize function had to be refined.

knit8 ULN 2803

knit7The big connector is printed with a 3D printer

knit5The connector with 10 and 8 pins are made from 2 5 pins connectors

knit6 The board with 2 extra potmeters to make the analog read run at 3.3V.

knit4 The Teensy 3.1

knit2 Testing the knitting from the board

Teensy (arduino script):
http://contrech.home.xs4all.nl/scripts/KH-940_teensy_test_knitting.zip

Processing sketch:
http://contrech.home.xs4all.nl/scripts/knitImageInArray15a_teensy.zip

Sock

After the knitting sessions at the e-textile summercamp it became obvious that the next thing to develop was a high-tech machine knitted sock.

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This sock is made with a KH-940. This hackable electroknit machine is handled fully manually to produce this sock.

The instructions for making this type of sock can be found at: http://www.machine-knitting.net/machineknittingnet/machine-knitting-a-sock-instructions/

The sock consists of acrylic yellow and a middle part of conductive wool.

(Nm10/3 conductive yarn
Company: plug and wear
Characteristics: Nm10/3 conductive yarn, 80% polyester 20% stainless steel, light grey, Surface resistance < 100000ohm)

The connection is reinforced by knitting some tours of silver thread at the ends of this strip.

(High Flex 3981 7X1 Silver 14/000
company: Karl Grimm
Characteristic: Very conductive, Solder-able)

ps4 The two types of conductive yarn.

ps3 The silver thread is visible at the start of the strip. This will distribute the current evenly.

The resistance of this strip between the two strands is around 2K Ohm.

This makes this version not yet fit for becoming a foot warming sock. For real warming up a few Watt at least is needed. P = V * I and V = I * R, so a resistance of 2K at a voltage of 10V results in a current of 5mA. This gives 50 mWatt, not enough for warming up. The resistance has to be reduced to 50 Ohm to be able to produce 500mA needed for (a bit of) warming up.

In the next sock another type of conductive thread will be used for the warming up application. This  higher resistance version can be used for signaling (connecting to another conductive strip) or probing the variable resistance when walking.

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2015 e-textile summercamp in pictures

For a week, e-textile designers from all over the world were together in Poncé sur le Loir, in the middle of France as guests of the art center Les Moulins de Paillard.

su3The staggering main workspace

su2filling up totally with projects during the week

Impressive were the projects: tools, education, printing, wifi, mass production amongst others, read more about projects at the summercamp website.

su1the knitting area, we had 4 knitting machines, all “hacked”, that is to say we could transfer images to the knitter using either AYAB, img2track or our own software.

su5 besides the main theater there was a very organized print room, with smart printing experiments

su4 A back stage picture of the exihibition space, also in this bunch of buildings near the Loir river.

A post documenting the Knitting group can be found here: http://etextile-summercamp.org/2015/documenting-knitting-group/. On this site more information can be found, like participants, subject matter, and lot’s of other pictures.

Linking the 2015 Swatch

After the knitting of the swatch, two sides had to be linked on a circular linker. It saved time to attach 4 or 5 swatches at the same time. So the swatches are draped around the linker.

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After linking two sides, one side remained open for inserting the magic. One layer of plastic and one layer of paper, — both insulators — with aluminum foil at the back connected to a rectifier bridge can make a LED flash when you knock on the two layers.

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The two layers had to be inserted into the swatch. The polyesther threads will help the tribo electric effect a little bit (hopefully :-).

After inserting the 30 double layers the second linking closed the swatch. A bit of caring for some stray wires and the production is finished.

Knitting the 2015 Swatch

At the coming e-textile summercamp the Swatches will be exchanged. The Swatch is a sample of small size showing some aspect of a combination of textiles and electronics. A group of e-textile designers willing to put a lot of work into this exchange all make 30 samples and these samples will be distributed at our meeting in Paillard, France.

Making a prototype is easy. Normally there are 3 – 5 versions necessary to have a finalized version which is presentable. But than making 30 copies is another business. You have to organize all the needed components (most of the time you have “some”, but not 30 and then find the same things like the knitting yarn, or the same conductive thread is sometimes even impossible!).

And e-textile designers are experimenters, so we like to change and always look for possible improvements. So making 30 identical copies is … stress!

In my production time there are three phases: the first phase is slow, because I really have to start the production, make it a bit “faster”, modular, more efficient. Then all stages are getting into my system and production is started. But in the last phase I have to be careful to stay concentrated, I get careless start thinking of other projects, and am likely to make stupid mistakes.

My swatch, after making the first prototype, is now divided into three production events:

knitting: knitting the envelop

electronics: making the tribo electric “battery” and connecting the rectifier bridge and the LED

linking: putting knitting and electronics together and close the envelop by linking.

These three production phases ask for different types of concentration. With the knitting the knitting machine – laptop combination must be working impeccably. I had a problem with the board (lobotomy of the KH-940). What was wrong with the board? In the end, after checking all the connections of this fragile board, it was the USB cable! Replacing the cable solved all connection problems. Who doubts his USB cable???? In this knitting phase eventually during production I make all possible mistakes. Forgetting the weights, reversing the cast of order, breaking threads, etc, etc, etc. With machine knitting you can make a lot of mistakes indeed!

The electronics are reduced, but still this can go wrong: in my first sample after linking the knitting (closing the envelop) a wire got detached. Good for the production: make sure the wires are very very very well connected, because the knitting will not facilitate soldering inside!

The linking can be done by hand, but as a hand stitcher it would take me another week…so a linker machine is used. Of course arriving at this linker at school it is out of production. First I had to repair it. But then things go smooth.

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The 30 copies knitted, not linked yet.

Description of this swatch can be found here:http://etextile-summercamp.org/swatch-exchange/flash-knit/

All coming swatches can be seen here:http://etextile-summercamp.org/swatch-exchange/

E-textile summercamp 2015:http://etextile-summercamp.org/

sw2

Knitted at the KH-940

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Knitting Pattern, for lace knit.