Knitectonics
Chapter II
Techniques & Experimentation
techniques & experimentation
Knitted fabric combining cotton and copper
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Knitectonics
Knitted Fabric
Knitting is a technique for constructing a two-dimensional fabric structure from a continuous length of one-dimensional yarn or thread. The origins of knitting in history, with respect to place and era are debatable. As it does not require a large equipment, it has been a valuable technique for nomadic people. However, the basic technique was introduced to Europe in the early 14th century. With the circular loom, household knitting was mechanized in the 18th century and was further engineered to sophistication with power-run machines during the Industrial Revolution. The technique of knitting holds immense potential due to the continuity of material, which allows to create flexible fabric, with different pattterns and the capacity to knit to shape.
Frederickson circular loom machine (1928)
Ladies knitting room _ France (1770)
Circular loom (XVIII century)
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Mechanical circular knitting machine
techniques & experimentation
B
A
2
1 Right Pin
Right Pin
Left Pin Left Pin
Principles of hand knitting Knitting has a rich vocabulary of knitting stiches. The most basic stitch is interlooping, where yarns are formed into loops, each of which is typically only released after a succeeding loop has been formed and intermeshed with it, so that a secure ground loop structure is achieved. Here, in diagram A, the left-hand left pin retains the previously formed course i.e. a row of loops and the right-hand pin draws through and retains the next course of loops, one at a time. In diagram B the left pin draws the newly formed loop 2, through loop 1 of the previous course. Left pin releases loop 1, which hangs from loop 2 on right pin. ( Note that loop 1 has been drawn under the head of the lower loop and that loop 2 has been drawn over the head of loop 1) Knitting Machines Knitting machines use the same principle as traditional hand knitting, but with the advantage of efficiency. Two basic machines are used at an industrial scale, the linear knitting machine and the circular knitting machine. Circular Knitting Machine
Linear Knitting Machine
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Knitectonics Knitting Stitch Variations
Interlooping
Float stich
Tuck stich
Loop transfer stich
Tucking over
Floating across
Commencing on empty rib
Tubular welt
Roll welt
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A jour knupf
Racked welt
techniques & experimentation
The machine we use is a circular knitting machine with forty four needles. Two basic topologies are possible with the machine, depending on the direction of movement of needles. If moved continuously, a cylinder is formed. If moved in clockwise and anticlockwise directions alternately, then a flat surface is created. The horizontal intermeshed loops are referred to as ‘courses’ and the vertical connections are denoted as ‘wales’. Our first set of experiments were aimed at understanding the knitting mechanics of the circular knitting machine in terms of yarns and needles. The topology, density and rigidity of the knitted output were found to be dependent on the yarn (type and number of yarns) and needles (distance between the needles and the direction of movement). We also attempted at mixing different types of yarns to harness the desired properties of different materials. Machine Movements Cylinder Surface - One Direction
Flat Surface - Back and forth
Knitting Machine Parts (1) Machine control: Lever for the control of the machine’s mechanisms. (2) Cylindrical gear: Rotates the track for needles. (3) Needles: 44 plastic needles with a flexible sinker to hold and release the knot. (4) CAM System: Raises the needles into position to take the yarn and release the previous knot.
3
2
4
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1
Knitectonics New yarn
Old loop
5 4 3 2 1
Clearing Cam
Wale
Course
Stitch Density
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techniques & experimentation
Knot variations
Regular Loops - All
Regular Loops - Alternate
Topology variations
+
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Irregular Loops
Knitectonics Material: Type of fiber - One
Single strand - Cotton fiber
Single strand - Copper wire
Multiple strands - Cotton fibers
Multiple strands - Cotton fibers
Material: Types of fibers - Multiple
Cotton fiber + Wool
Wool + Jute fiber
Wool + Nylon monofilament
Cotton fiber + Copper wire
Material: Rigidity
Non- rigid: Cotton Fiber
Semi-rigid: Cotton fiber + Copper Wire
Semi-rigid : Cotton fiber + Partial Resin
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Rigid : Cotton fiber + Resin
techniques & experimentation
Material Distribution and Density
Resultant material accumulation (Creating openings)
Irregular loop variations ( Skipping needles)
Regular loop variations (Skipping needles) 40
Knitectonics
Regular loops
To break the generic forms offered by the machine, we mixed the cylindrical form and flat surfaces, thereby generating new topologies and understanding ways in which material could be differentially deposited to form masses and voids. We then established parameters for designing knit structures on the basis of these experiments. We could build sparsely/ densely, non-rigid/ semi-rigid/ rigid and create masses/ voids etc.
Irregular loop variations (Skipping needles) 41
techniques & experimentation
Decoding system Decoding ‘forward movement’ function
Understanding technique and material
Code generated
Callibrating simulation system with material properties
Multi-material
Machine path
Fabric simulation
In order to add complexity to the simple knitting machine, it was imperative to create complex geometries on the machine. Further, for converting it to a digital machine, we began digitising the process by translating the analogue models to digital codes that depict the numeric rules the machine works on. Since the material properties i.e. the type, thickness, cross section etc. of the yarn govern the behaviour of the knitting, we developed a simulation system for understanding and demonstrating material behaviour. In the above images, white represents a single yarn, the orange and the blue represent two 42
Knitectonics
Decoding ‘backward and forward’ movement function (by releasing the knots)
Function to create holes
Releasing knots
Code generated
Machine path
Simulation
Fabric simulation
and three yarns respectively. We see that for a particular yarn, as the number of strands increases, the elasticity of the fabric reduces. We simulated the knitting mechanism based on certain rules. The white dots in the above images represent continuous circular movement and the orange dots represent the alternating movement, without completing a circle. The rule followed here is that the needles first move continuously for a few rows. Then half the needles alternate between forward and backward movement and in the process, the remaining needles drop their loop. Finally when it resumes the constant continuous movement, the new loops formed create a puncture in the surface. 43
techniques & experimentation
Decoding ‘back and forward’ function (by holding the knots)
Function to create bends
Back and forward
Code generated
Machine path
Simulation
Fabric simulation
In the rule on the previous image if instead of dropping, we retain the loops on the needles while alternating between forward and backward and then resume continuous knitting, we are able to add material differentially.
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Knitectonics
Speculation from different rules
Code prescribed
Fabric simulation
Code prescribed
Fabric simulation
Code prescribed
Fabric simulation
Code prescribed
Fabric simulation
Using different rules for the forward and backward movement and dropping or retaining of loops, we get unexpected results. The above images are some speculative three dimensional digital models. 45
techniques & experimentation
Horizontal deployment model
Horizontal deployment model _ Junction detail
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Knitectonics
Horizontal deployment model _ Interior View
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techniques & experimentation
Digital simulation through ‘Processing’ allowed us to simulate multiple possibilities of deploying the knitted fabric, specifically in vertical and horizontal scenarios. Our analogue machine has a limitation as it had a maximum of 44 needles, so to study the implication of realtime scale on the behaviour of the fabric, we simulated 200 needles.
Structure We developed a catalogue of different patterns, to embed structure into the fabric, which could possibly counter various structural forces locally and globally, in vertical and horizontal scenarios. One yarn Code
Two yarns Vertical Application
model S1
model S2
model S3
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Three yarns Horizontal Application
Knitectonics Code
Vertical Application
Horizontal Application
model S4
model S5
model S6
model S7
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techniques & experimentation
Code
Vertical Application
model S8
model S9
model S10
model S11
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Horizontal Application
Knitectonics Morphologies
The knitting process allows us to have the forward and backward movement in the sequencing of needles. The variation of these two movements, allows us to accumulate material in different areas to define new morphologies. A continuos movement produces the cylinder while the back and forth movement knits a flat surface, by combining them we can variate the knitted fabric. Code
Vertical Application
Horizontal Application
model M1
model M2
model M3
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techniques & experimentation
Code
Vertical Application
Horizontal Application
model M4
model M5
Resin Deposition
Considering resin as the material to solidify the knitting, by varying the application and amount of resin across the surface, we can achieve both flexibility and rigidity and create different deformations of the fabric. We were able to explore different geometric grids or patterns for coding the resin deposition into the surface.
Code
Vertical Application
model R1
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Horizontal Application
Knitectonics Code
Vertical Application
Horizontal Application
model R2
model R3
model R4
model R5
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techniques & experimentation
Openings
At the macro scale, the punctures we create with the forward and backward movement of needles could be articulated as openings or junction connections.
Code
Vertical Application
model O1
model O2
model O3
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Horizontal Application
Knitectonics Code
Vertical Application
Horizontal Application
model O4
model O5
model O6
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techniques & experimentation
CNC Machine Due to the time consuming process it became imperative to develop a computer numerically controlled machine that can take the digital information from a numeric code and knit. This required hacking of the machine in two aspects: - Mechanize the knitting process and digitally control movement and magnitude of forward and backward movement. - Digitally count the needles and mechanize the process of needle control to be able to select needles In order to digitally control the clockwise and anticlockwise movement of the machine, we connected the machine to a stepper motor, run by G-code. The G-code is run by the number of pulses required to move from one needle to the next, hence making it possible to choose the magnitude by which the machine moves in a direction.
Needle counter
Code
Needle selection
Translate void model01( ){ knit(40,1); for (int i = 0; i < 13; i++){ reverseDirection(); knit(21,1); } reverseDirection(); knit(25,1); knit(44,15);
Arduino Board
}
Step Motor
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Knitectonics clockwise
10 or less to stop
STOP
10 or less to stop
anti-clockwise
Needle Counter System
Arduino Board counter = 01 counter = 02 counter = 03 counter = 04 counter = 05 counter = 06 counter = 07 counter = 08 counter = 09
counter = 10 counter = 11 counter = 12 counter = 13 counter = 14 counter = 15 counter = 16 counter = 17 counter = 18
counter = 19 counter = 20 counter = 21 counter = 22 counter = 23 counter = 24 counter = 25 counter = 26 counter = 27
STOP( ); REVERSE( ); counter = 01 counter = 02 counter = 03 ....
To digitally control the needles, we introduced a system of sensor connected to the Arduino, which recognizes the needles and gives the needle count as output information on the computer. Based on the digital code, it flashes separate LEDs to inform when it is moving clockwise, when it is at the zero position and when it starts moving in the anticlockwise direction. The needle selection is mechanized, by modifing the Cam system of the original machine. In the original machine, there is a mechanical ramp system which forces a knot on each needle. We modified it by creating two circulation paths for the needle, one in which it goes up the ramp and creates a knot and the other where the needle goes straight and skips making a knot. Combining these two aspects we get a digitally controlled machine. Extising Cam
Modified Cam - Circulation 1
Modified Cam - Circulation 2
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techniques & experimentation
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Knitectonics
Double skin detail model
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techniques & experimentation
TWO MACHINES WO MACHINES TWO MACHINES SAME DIA) (SAME(SAME DIA) DIA)
TWO MACHINES
MACHINES TWO TWO MACHINES M2a _(SAME Same Diameter (SAME DIA) (SAME DIA) DIA)
TWO MACHINES TWO MACHINES TWO MACHINES (DIFFERENT (DIFFERENT DIA (DIFFERENT DIA DIA OUTPUT OFMACHINE BIG MACHINE OUTPUT OF BIG MACHINE OUTPUT OF BIG INSIDE THE SMALL MACHINE) INSIDE THE SMALL MACHINE) INSIDE THE SMALL MACHINE)
TWO TWO MACHINES TWOMACHINES MACHINES (DIFFERENT DIA M2b _(DIFFERENT Different DIA (DIFFERENT DIA Diameter OUTPUT OF MACHINE OUTPUT OF BIG MACHINE OUTPUT OFBIG BIG MACHINE Output of big machine inside INSIDE THE MACHINE) INSIDE THE SMALL MACHINE) INSIDE THESMALL SMALL MACHINE)
a small machine
TWO MACHINES WO MACHINES TWO MACHINES SAME DIA) (SAME(SAME DIA) DIA)
Double
TWO TWO MACHINES TWOMACHINES MACHINES
(DIFFERENT DIA M2c _ Different Diameter (DIFFERENT DIA (DIFFERENT DIA OUTPUT OF MACHINE OUTSIDE OUTPUT OF BIG MACHINE OUTSIDE OUTPUT OFBIG BIG MACHINE OUTSIDE THE MACHINE) Output of SMALL small machine inside THE SMALL MACHINE) THE SMALL MACHINE) a big machine
TWO MACHINES TWO MACHINES TWO MACHINES (DIFFERENT (DIFFERENT DIA (DIFFERENT DIA DIA TWO MACHINES OUTPUT OFMACHINE BIG MACHINE OUTPUT OFTWO BIG MACHINE TWO MACHINES TWO MACHINES TWOMACHINES MACHINES TWO MACHINES OUTPUT OF BIG DIA (SAME DIA) Skin with Two Machines INSIDE THE SMALL MACHINE) (DIFFERENT (SAME (DIFFERENT DIA DIA (SAME DIA) DIA) INSIDE THE(DIFFERENT SMALL MACHINE) INSIDE THE SMALL MACHINE) OUTPUT OF BIG MACHINE OUTPUT OFMACHINE BIG MACHINE OUTPUT OF BIG INSIDE THE MACHINE) INSIDE THE SMALL MACHINE) INSIDE THESMALL SMALL MACHINE)
TWO MACHINES TWO MACHINES TWO MACHINES (DIFFERENT (DIFFERENT DIA (DIFFERENT DIA DIA OUTPUT OFMACHIN BIG M OUTPUT OF BIG MACHINE OUTPUT OF OUTSIDE BIG THE SMALL MACHI THE SMALL MACHINE) THE SMALL MACHINE)
TWO MACHINES TWO MACHINES TWO MACHINES (DIFFERENT (DIFFERENT DIA (DIFFERENT DIA DIA TWO OUTPUT OFMACHIN BIG TW MT OUTPUT OF BIG MACHINE OUTSIDE TWO MACHINES TWOMACHINES MACHINES OUTPUT OF BIG (DIFFERENT DIA (DI THE SMALL MACHI (DIFFERENT DIA SMALL (DIFFERENT DIA (D THE SMALL MACHINE) THE MACHINE) OUTPUT OF BIG MACHINE OUTSIDE OU OUTPUT OFMACHINE BIG MACHINE OUTSIDE OUTPUT OF BIG OUTSIDE THE MACHINE) THE SMALL MACHINE) THESMALL SMALL MACHINE)
After researching the tectonic possibilities and limitations of a single machine, we began exploring the implications of introducing a second machine and studying the machine configurations possible. By studying five different scenarios, with varying diameter of two machines and the placement and sequencing of the output, we discover the possibility of having double skin structures. Diagram M2a shows two machines with same diameter fabricating simultaneously, to create a double wall wherein connections can be determine at different points of the perimeter. Diagram M2b shows the output of a big machine into a small machine, creating some excess of fabric inside the small machine. By folding the excess we can reinforce the structural capacity of the wall. Diagram M2c inverts the previous output, and the excess of material is located outside of the inner ring. Diagram M2d repeats the output of big machine inside a small machine with a irregular distribution in the points of connection between the two walls. Diagram M2e repeats the output of small machine inside a big machine with irregular distances between the connecting points. We see the tectonic possibilities of the cavities created between the double skin, for structural performandce, the inclusion of services or even creating habitable spaces. 60
TW T (DI (D OU O INS IN
O INS IN
NEOUTSIDE OUTSIDE NE
Knitectonics
TWOMACHINES MACHINES TWO (DIFFERENTDIA DIA (DIFFERENT OUTPUTOF OFBIG BIGMACHINE MACHINE OUTPUT INSIDETHE THESMALL SMALLMACHINE) MACHINE) INSIDE
TWOMACHINES MACHINES TWO (DIFFERENTDIA DIA (DIFFERENT OUTPUTOF OFBIG BIGMACHINE MACHINEOUTSIDE OUTSIDE OUTPUT THESMALL SMALLMACHINE) MACHINE) THE
MACHINES TWO MACHINES TWO MACHINES M2d(DIFFERENT _ Different DiameterDIA RENT DIA (DIFFERENT DIA UT OF BIGOUTSIDE MACHINE OUTSIDE OUTPUT OF BIG MACHINE MACHINE OUTPUT OF BIG MACHINE Output of big machine inside MALL MACHINE) SMALL MACHINE) HINE) INSIDE THEINSIDE SMALLTHE MACHINE)
TWO MACHINES TWO MACHINES (DIFFERENT DIA M2e _ Different Diameter (DIFFERENT DIA OUTPUT OF BIGOUTSIDE MACHINE OUTSIDE OUTPUT OF BIG MACHINE Output small machine inside THE SMALL MACHINE) THE SMALL MACHINE)
TWOMACHINES MACHINES TWO (DIFFERENTDIA DIA (DIFFERENT MACHINES TWO MACHINES TWO MACHINES NEOUTSIDE OUTSIDE OUTPUT OFBIG BIG MACHINE NE OUTPUT OF MACHINE RENT DIA (DIFFERENT DIA (DIFFERENT DIA INSIDE THE SMALL MACHINE) INSIDE THE SMALL UT OF BIG MACHINE OUTSIDE OUTPUT OFMACHINE) BIG MACHINE MACHINE OUTSIDE OUTPUT OF BIG MACHINE
TWOMACHINES MACHINES TWO (DIFFERENTDIA DIA (DIFFERENT TWO MACHINES TWO MACHINES OUTPUT OFBIG BIGMACHINE MACHINEOUTSIDE OUTSIDE OUTPUT OF (DIFFERENT DIA (DIFFERENT DIA THE SMALL MACHINE) THE MACHINE) OUTPUT OF BIG MACHINE OUTSIDE OUTPUT OF BIGSMALL MACHINE OUTSIDE
MALL MACHINE) HINE)
a small machine
SMALL MACHINE) INSIDE THEINSIDE SMALLTHE MACHINE)
a big machine
SMALL MACHINE) THE SMALLTHE MACHINE)
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techniques & experimentation
Section of double skin model
Detail of double skin model
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Knitectonics
Double skin model
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techniques & experimentation
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Knitectonics
Double skin detail model
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techniques & experimentation
The aspiration is to employ multiple knitting machines of various sizes interacting and creating a range of spatial configurations. But any material system for novel tectonic intentions requires structural validation. We used a modest model, knitted and solidified, weighing 100 grams to test the structural capacity of knitting and fibre composites. The model successfully withstood a weight of 700 times its own weight, for an appreciable length of time without collapsing. The structural validation of the strength of knitting, along with our understanding of programming of knitting for surface articulation and material behaviour, brought forth the evidence that an everyday craft of knitting, on simple household machines, could indeed facilitate envisioning the possibility of a proto- fabrication system.
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Knitectonics
â&#x20AC;&#x2DC;...could a everyday craft of knitting facilitate the possibility of a prototypical fabrication system?..â&#x20AC;&#x2122;
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Frozen Fibers S a n h i t a C h a t u r v e d i [India] E s t e b a n C o l m e n a r e s [Colombia] T h i a g o M u n d i m [Brazil]
Tutors
Marta MalĂŠ-Alemany Jeroen van Ameijde Daniel Piker
www.knitectonics.com
Machinic Control 2.0 Design Research Lab v13 Archit ectural Association London Phase II Copyright Š Frozen Fibers 2011, otherwise indicated and used only for academic purposes.