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STONE SPRAY Anna Kulik Inder Prakash Shergill Petr Novikov


STONE SPRAY SOIL SOLIDIFYING ROBOT Project made by Anna Kulik, Inder Parkash Shergill, Petr Novikov Tutors: Marta Male-Alemany, Jordi Portell, Miguel Lloveras


REFERENCE


REFERENCE IAAC

DS3 Digital Tectonics Year 2012 www.iaac.net

FAB LAB BCN Year 2011-2012

http://fablabbcn. org/

Flight Assembled Architecture Gramazio and Kohler Year 2011-2012 p. 9-10

http://www. gramaziokohler. com/web/d/projekte/209.html

Contour Crafting Behrokh Khoshnevis Year 1997 p.9-10

http://www.contourcrafting.org/

Bacilius Pasteurii

Magnus Larsson Year 2009 p. 20-21 http://www.magnuslarsson.com/

Areana Project IAAC Year 2011 p. 20-21

http://www. youtube.com/ watch?v=eh_ nPukhPY8/

Rubber Project IAAC Year 2011 p. 20-21

Solar Sinter

Marcus Kayser Year 2011 p.9-10 http://www. markuskayser.com/

Radiolaria

Polypavement Soil solidifier Year 2008 p. 20-21

http://www.polypavement.com/

Enrico Dini Year 2008 p.9-10

Andrew Payne

http://www.dhubbcn.cat/node/408

http://www.liftarchitects.com/

Sand Information

Michalatos Panagiotis

Wikipedia p.18-19

http://en.wikipedia. org/wiki/Sand/

Robotic Arm p.74-75

Simulation p.64-65

http://sawapan.eu/

Arduino

Robotic Arm Year 2011 p. 74-75 http://www.magnuslarsson.com/

Easy Driver Robotic Arm p.74-75

http://www.sparkfun.com/

Processing Simulation Year 2011 p.64-65

http://www.processing.org/


CONTENTS


INDEX / CONTENTS Introduction 1 Critical views

11

2 Material

17

Size Materials Conclusions

25

63

8 Robotic arm

73

9 Proposals

83

10 How to ?

87

11 Thank you

93

Explanation Robotic arm prototype Choreography of robotic arm Comparing chairs Conclusions

4 Deposition. Nozzles

33 Deposition ways Spraying Nozzle v.1.0 // work Nozzle v.2.0 // work Conclusions Nozzle v.3.0 Possibilities // Issues // Conclusions

Technique Results Conclusions

7 Program

Rules Form Analysis of form according to m. f. Optimisation Simple Box Exploring the maximum

Hard mix + Liquid Mix Features to achieve Conditions and studies Series and Mixes Conclusions

5 Possibilities. Formwork

51

Columns Sand Monolit Sand Henge Conclusions

Material research // On-Site Local Identity of the place Soil // Sand Granular materials Solidification Conclusions

3 Material experiments

6 Possibilities. No formwork

45

Architectural proposals

Make your own nozzle?


INTRODUCTION


INTRODUCTION

Thesis Additive manufacturing is an avant-garde research topic. At the present time this subject is excessively explored in advanced institutions all over the world. This book describes the additive fabrication research project that is called Stone Spray Project. It was done by Anna Kulik, Inder Prakash Singh Shergill and Petr Novikov in the Institute for Advanced Architecture of Catalonia under the supervision of Marta Male-Alemany and assistance of Jordi Portell with Miquel Lloveras. The research started in January 2012 and accomplished in July 2012. The main task of the project was to invent a system that could digitally fabricate architecture on-site. Furthermore it was required to implement robotics in this process. During this research a lot of experiments with materials, machines and electronics took place, they were carefully documented and the most important of them are included in this book. As a result of Stone Spray project several structure samples were produced as well as a working robot prototype.

9


CHAPTER 1 CRITICAL VIEWS


CHAPTER 1. CRITICAL VIEWS

“WHAT ARE THE ADVANTAGES OF THE WORK DONE BY A ROBOT?”

Why robot? Before starting to choose the material or process, it was very important to answer a question: “What are the advantages of work done by a robot, compared to the work done by people?“ What should the robot do to be more efficient than people and to be irreplaceable? To answer this question some of the existing robots were analysed in the field and pointed out their advantages and disadvantages.

11


Flight Assembled Architecture Gramazio and Kohler

Contour Crafting

Behrokh Khoshnevis

Solar Sinter

Marcus Kayser

Radiolaria Enrico Dini


Advantages

On-Site Fabrication No building trash Size High precision

CHAPTER 1. CRITICAL VIEWS

EXISTING ROBOTS

Disadvantages

Pre-fabricated components

Advantages

Speed No formwork

Disadvantages

Only one material used Size of robot compared to the result

Advantages

On-Site Fabrication Zero-energy use Site material use

Disadvantages

Only one material used - sand Size of robot comparing to result

Advantages

Nature-like structures Architectural scale product

Disadvantages

Size of robot comparing to result

13


CHAPTER 1. CRITICAL VIEWS

Conclusions Analysing the references, it was concluded that the final robot prototype needed to fulfill the below mentioned conditions: • • • • • • • • • • •

14

On-Site Fabrication High Precision Use of existig On-Site materials Multimateriality Zero Energy use Naturally Friendly Nature-like structures Architectural scale product Transportable size No building trash Low cost


15


CHAPTER 2 MATERIAL


CHAPTER 2. MATERIAL

“IDENTITY OF PLACE FOR THE ROBOT OR FOR A DESIGNER?...�

Material research On-Site materials Speaking about using on-site materials the first question which appeared was the Site. Without knowing the Site how can we understand what is going to be the Material On-It? What if the Site is any part of our planet? In this case we are producing a robot for everyones use, you can just take it and go wherever you want to built something directly from what you can find there. This would give the robot the chance to work with multiple materials. And thinking about something that can be found all over the world, the idea of using soil came up. Use of different types of soil would always give its output a local identity of the place. Should we leave the question of local identity to the robot or the designer?

Diagram of identity of place

17


CHAPTER 2. MATERIAL

Primary - Dry component Granular materials It was decided to work with soil, but sand was used for the experiments as it is a locally available material. Sand, is one of the most basic mineral formations on the planet, it can be found in some quantity in every country, temperate zone, geographical region and continent around the globe. Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. The composition of sand is highly variable, depending on the local rock sources and conditions (which brings up the question of identity of place again), but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz.

Granular materials


Secondary - Additive How to choose? Sand being granular in nature it was needed to understand which component could work with the particles, bind them together and solidify the result. A series of questions were defined to choose the required soil-solidifier. • • • • • • • • •

What is the availability In which amount Ecological issues Multimateriality Drying time Strength of construction Water resistance Repairing issue Recycle / Reusing / Waste

19


Bacilius Pasteurii Magnus Larsson

Natural Glue IAAC 2011

Rubber

IAAC 2011

Polypavement Used for roads


Advantages

Environmentally friendly Applicable to any sand Structural strength

CHAPTER 2. MATERIAL

ADDITIVE

Disadvantages

No reference to real projects Lack of information

Advantages Very cheap Easy to get Non-toxic

Disadvantages

Slow drying time Non reusable

Advantages

Easy to find Works with any type of soil Fast drying time Structural strength

Disadvantages Toxic in nature

Advantages

Easy to get in any amount Fast drying time Structural strength Works with any type of soil No waste

21


CHAPTER 2. MATERIAL

Conclusions After analysing all the materials it was decided to continue working with Polypavement, as it has the best material properties. As there was no architectural projects, which had used this material other than roads solidification, it was a big challenge. • What is the availability? Broadly available • In which amount? Any amount • Ecological issue? LEED certified • Multimateriality? Works with any natural granular material • Drying time? Short • Strength of construction? Rock hard • Water resistance? Absolutely water resistant • Repairing issue? Solves by pouring more mix on the problematic area • Recycle / Reusing / Waste? No waste, can be easily reused

22


23


CHAPTER 3 MATERIAL EXPERIMENTS


CHAPTER 3. MATERIAL EXPERIMENTS

“% OF HARD MIX + % OF LIQUID MIX = ?�

Hard mix + Liquid mix Before starting the physical tests it was vital to find the right proportion between the hard mix and the liquid mix. As there were no reference projects which had used these materials in combination. A series of tests needed to be developed to test the different proportions between hard and liquid mix.

Hard mix It consists of 95% sand and 5% cement by volume. (Cement was used in the initial tests but later use of cement was discontinued)

Liquid mix It consists of Water and Polypavement in a proportional mix.

Hard Mix Sand + 5 % of cement per volume

%

vs

%

Liquid Mix Water % + PolyPavement %

Diagram of proportions

25


CHAPTER 3. MATERIAL EXPERIMENTS

Conditions and Studies Understanding the goals of the project and the results which were to be achieved, tests were started by mixing materials and comparing results.

Environmental Conditions: • Temperature • Sunlight • Fresh air To test the environmental conditions, the materials were mixed indoors and outdoors. Average indoor temperature was 100C, without any fresh air or sunlight, average outdoor temperature 25-270C, with fresh air and plenty of sunlight. It was observed that due to air movement and sunlight the drying time of the mix was dramatically decreased by 80%.

Parameters

Studies regarding what needed to be understood: • • • • •

Strength Resolution Viscosity Abrasiveness Setting Time

Response Surfaces [from left to right]: Average, Abrasiveness, Drying time


Series and Mixes Response Surfaces To find the right proportion of the mixes the experiments were divided into series and mixes.

Series The series compared the results based on the proportion of hard and liquid mix. eg 60% Hard Mix - 40% Liquid mix

Mixes The mixes are part of the series. That test the proportion of water and Polypavement together, which combine to form the liquid mix to the given proportion of hard mix. To compare the test results response surfaces were generated, to study each of the required parameters and finding the best performing sample. This helped as a particular mix in a series might be good in resolution or setting time but might not be performing well in strength. The surfaces gave a visual reading of the performance of the tests. Generated a final surface with the average of all the relevant.

Response Surfaces [from left to right]: Viscosity, Strenth, Resolution

27


Series 1 90 % Lq + 10 % Hd

Series 2 80 % Lq + 20 % Hd

Series 3 70 % Lq + 30 % Hd

Series 4

Series 5

60 % Lq + 40 % Hd

Series 6

50 % Lq + 50 % Hd

40 % Lq + 60 % Hd

Series 1-7 Mix 1

Mix 3

0 % PP + 100 % W

20 % PP + 80 % W

Mix 5 40 % PP + 60 % W

Mix 7

Mix 9

60 % PP + 40 % W

Mix 11

80 % PP + 20 % W

100 % PP + 0 % W

viscosity

strenth resolution

abrasiveness

Series 8 Mix 1 0 % PP + 100 % W

Mix 3 20 % PP + 80 % W

Mix 5 40 % PP + 60 % W

Mix 7 60 % PP + 40 % W

Mix 9

Mix 11

80 % PP + 20 % W

100 % PP + 0 % W

tion

resolu

strenth abrasiveness

viscosity

Series 9 Mix 1 0 % PP + 100 % W

Mix 3 20 % PP + 80 % W

Mix 5 40 % PP + 60 % W

Mix 7 60 % PP + 40 % W

Mix 9

Mix 11

80 % PP + 20 % W

100 % PP + 0 % W

resolution viscosity

strenth abrasiv

eness

Series 8.5


Series 1-7 CHAPTER 3. MATERIAL EXPERIMENTS

Series Conclusions

The proportion of the liquid mix to the hard mix decreases the workability of these tests.

SERIES OF MIXES

Series 8

20 % Lq + 80 % Hard

Series Conclusions

Although results were better than the previous series as it is more viscous, it still takes a long time to set.

Series 9

10 % Lq + 90 % Hard

Series Conclusions

The series high proportion of sand makes the mix too dry and difficult to work with.

Series 8.5

15 % Lq + 85 % Hard

Series Conclusions

The series fares well in all parameters.

29


CHAPTER 3. MATERIAL EXPERIMENTS

Conclusions Based on the material tests the right proportion of hard and liquid mix was found. It was observed that as the series progresses the drying time decreases because the liquid content in the material is less.

30


31


CHAPTER 4 DEPOSITION. NOZZLES


CHAPTER 4. DEPOSITION. NOZZLES

“PRINT IT? SPRAY IT? MOULD IT?..�

Deposition Techniques After finding the right proportion of the material mix. The next step was to find the right deposition technique for material deposition. Creating a mould could be interesting research path but it is a static system and the material behaviour would be dominated by the confines of the cast. The idea was to come up with a system that would be very versatile.

Conclusions From the basic research a system was required in which the material comes in contact with air when deposited and also was a flexible system in terms of movement and the material flow is controllable.

Spraying / Pouring / Shooting experiments

33


Sand container

Sand mixes with Polypavement

Aerograph gun

Mix is spraying out

Polypavement goes into the gun

Polypavement container

Nozzle v.1.0 Explanations

Nozzle v.1.0 Photo

Growing on

Work with vertical surfaces

Connection to compressor


CHAPTER 4. DEPOSITION. NOZZLES

Nozzle v.1.0 It was needed to understand the technique which work with particle systems, binds them together and the result is solidified. It was necessary to formulate a list of questions, for selecting the relevant technique . A spray nozzle based on aerograph gun connected to a container filled with sand. This spray of polypavement and air is mixed with sand and then this mix shoots out of the nozzle and is finally sprayed on the surface where the structures are to be built.

Work

Fast deposition Fast drying time Adjustable distance of spray

Conclusions

It was found that this is an effective way of deposition but it needed to have more control in terms of hard and liquid mix deposition. As this system would not function effectively if multiple directions were introduced into the system. The final mix which excited from the nozzle was also not found to have the desired material proportion.

35


Sand container

Connection to compressor

Mixing point

Polypavement

Mix is going from here

Nozzle v.2.0

Based on aerograph

Nozzle v.2.0 Photo

Work

The wall, horisontal deposition

Sand is going from here


CHAPTER 4. DEPOSITION. NOZZLES

Nozzle v.2.0 After understanding the disadvantages of Nozzle v.1.0 the position of the hard mix container and the liquid mix container were moved away from the nozzle. It resulted in a nozzle which would work in multiple directions as the materials would not hinder the movement of the nozzle. Control of the material deposition still could not be achieved. The spray spread of the mix when it is ejected from the nozzle is based on the size of the opening and the distance of the opening to the surface where it is going to be deposited. Both the materials mix inside the nozzle before they leave the opening have a tendency of clogging up the nozzle. Due to the freedom of movement the final deposition of the material mix could be done in both vertical and horizontal directions.

Work

Fast deposition Fast drying time Adjustable distance of spray Works well in multiple directions

Conclusions

Needed more control in terms of hard and liquid mix deposition. Also the material mix has the tendency of clogging the nozzle before the final ejection of the mix.

37


Mixing points

1

2

3

Mixing points

The way of deposition V. 1.0. 100 mm

V. 2.0.

V. 3.0

150 mm

250 mm

V. 2.1

Resolution

PP deposition Nozzle end

200 mm Distance from the end of nozzle = const

Concentration of points


CHAPTER 4. DEPOSITION. NOZZLES

Improvements To fix the problem of the spray blast the length and the diameter of the nozzle end was changed. Only dry mix was tested in the process it was concluded that it worked well to shift the final mixing point between the materials to outside the nozzle than inside. In this case the problem of clogging could be eliminated. A syringe is connected to the liquid mix output and the liquid mix is sprayed on the shooting sand coming from the nozzle. This process helped in gaining control over the speed of hard and liquid mix deposition. The quantity of both the hard and liquid mix can be calculated and with little calibration of the speed of deposition, the final mix proportion would be achieved on the built form.

Advantages

No clogging of nozzle Controlled spray of hard mix Easy maintainance of nozzle

Disadvantages

Regulating continuous flow of material Portability

39


Connection to compressor

Sand container

Level of sand

PP syringe

Compressor

Connection of PP to nozzle

Nozzle end

Nozzle 3

2 jet sprays

Nozzle v.3.0 Photo

Connection to compressor

Sand feeder Diagram

Plastic tube - better transparent one

Plastic holders for tube

Connection to sand tube


CHAPTER 4. DEPOSITION. NOZZLES

Nozzle v.3.0 After understanding the deposition rates of the materials, the working nozzle had to be made portable for easy movement and gain the advantage of working on site directly.

Sand container

Consists of a plastic tube of X length and Y diameter. Using a transparent tube is better as in case of a clog the problem area can be rectified. It is connected to a compressor, the air pressure is used to push the sand from the nozzle and its deposition speed can be adjusted.

Liquid binder container

A syringe is connected to a linear actuator, and the liquid binder component is pushed out of the needle. Then the component mixes with the sprayed sand outside the nozzle.

Conclusions

Multidirectional Nozzle Control over feeder deposition Portable

41


CHAPTER 4. DEPOSITION. SPRAYING. NOZZLES

Conclusions Reducing the number of components in the nozzle helped in making a very manageable nozzle. Having a system in which the final mix is outside the nozzle helped in resolving the problem of clogging, and helped in making the system controllable and very precise. With multi directional deposition and understanding the material behaviour there is a possibility of spraying the material on already built structures.

42


43


CHAPTER 5 POSSIBILITIES. FORMWORK


CHAPTER 5. POSSIBILITIES. FORMWORK

“AS A FORMWORK WE DECIDED TO USE METAL WIRES”

Use of formwork It was needed to test the material in conditions where it is used in combination with existing geometry that acts as formwork for the sand. As a formwork aluminium wires were selected.

Technique Using metal wires a formwork would be created and using the nozzle the mixture would be sprayed on the formwork.

45


Support material Metal wires

Work

Form from wires

Work

Spraying on

Result

Sand stool


CHAPTER 5. POSSIBILITIES. FORMWORK

Work and results The first step involves in finding a form to be built using metal wires. The process consisted of finding the connection between different parts of the geometry and to create a network of curves then using the nozzle, to spray the mixture of sand and liquid mix over the aluminium mesh and to cover it with the material. The distance between the formwork and the nozzle has to be maintained as too much distance leaded to the material not spraying properly on the mesh and majority of the material falls down and becomes waste. The final output was a result of the formwork and the material deposition as the more time the material was deposited the thicker the members of the frame grew ,also some of the falling waste material has the tendency to deposit on some of the branches of the structure.

Advantages

Variety of shapes Easily constructed formwork Fast construction Quick drying time

Disadvantages

Manual calibration Big proportion of waste to builtmaterail

Time Taken: 45min

Material Usage:

Hard Mix = 700g Liquid Mix =100ml

47


CHAPTER 5. POSSIBILITIES. FORMWORK

Conclusions Although it is an interesting concept and technique, material behaviour cannot be explored to the maximum as the formwork dominates the final output of the structure. A lot of structure variations can be explored by following this method. But this path would be more of structure exploration than material research.

48


49


CHAPTER 6 POSSIBILITIES. NO FORMWORK


CHAPTER 6. POSSIBILITIES. NO FORMWORK

“REAL ADVENTURE LIES IN MAKING THE STRUCTURES WITHOUT FORMWORK..�

No formwork Working with a formwork is an interesting field of research but material behaviour is restrictive. The task is to achieve similar structures without formwork, to understand how the material behaves and how it reacts to stresses, environment and the form. To understand the material behaviour a series of experiments would be required to test the material in various areas. As the material works in compression it would be interesting to study the properties of the material at its extreme.

51


First columns Spiral path

First columns Close up

Result


CHAPTER 6. POSSIBILITIES. NO FORMWORK

First Columns The first task was to create a vertical column. Movement of the nozzle in the z -axis generates a column but its height is max 30mm. It was observed that the material requires a little self support for it to gain height. Moving the nozzle in the z-axis by taking a spiral path helped in achieving a height of 60mm. The drying time of the column is directly proportional to the width and height of the column. When the column is constructed it is very weak and fragile but it achieves it optimum structural strength after it is completely dry.

Work Basic column is constructed very fast It takes approx 5 min to dry the outer shell of the column Hard and liquid mix proportions are very important in achieving height Time Taken: Varies with column size Material Usage: Hard Mix = Varies with column size Liquid Mix = Varies with column size

Conclusions Different thicknesses of a column require different movement of the nozzle. A certain height can be reached if a certain path is taken. For continuous printing multiple geometries need to be created so there is time for the material to solidify.

53


2d columns

Triangular path

2d columns Close up

Result


CHAPTER 6. POSSIBILITIES. NO FORMWORK

Advanced Columns For achieving more height it was observed that using a triangular path and moving in the z axis in one continuous print the column could achieve a height of 120mm. As the material can stick to different surfaces it became possible to grow the columns even taller after they had dried completely without the loss of structural strength.

Work Time Taken: Varies with column size Material Usage: Hard Mix = Varies with column size Liquid Mix = Varies with column size

Conclusions Using a triangular spiral path the height of the column could be 120mm in one continious movement. The material has the property of continuing its growth after the form has solidified.

55


Sand Monolith

Combines pathes

Sand Monolith Close up

Form and path


CHAPTER 6. POSSIBILITIES. NO FORMWORK

Sand Monolith After understanding the basic behaviour of the material, experiments were done in making vertical surfaces. As the experiment progressed it was found that the material was taking a lot of time to dry. Openings in the surface helped in faster solidifying the material. As the structure gained height the openings also grew in size because material control was more understood. Due to the nature of the material and its property of sticking to already built forms it was possible to continue growing on the structure after a long break without the loss of structural strength and the structure would still be homogeneous.

Work The growth of the structure is very path intrinsic. A little deviation from the path leads the structure to grow in a different form. Openings can be of a certain width, height is not a constraint. Time Taken: 4 hrs Material Usage: Hard Mix = 1500g Liquid Mix = 220ml

Conclusions Possible to grow after long break in printing. Openings in surface help in decreasing setting time. Process of making different size openings is understood.

57


Multidirectional arcs Spiral pathes

Multidirectional arcs Close up

Form and Path


CHAPTER 6. POSSIBILITIES. NO FORMWORK

Sand Henge From the previous experiment it was found that the openings help decreasing the setting time of the material, as more surface area of the material is exposed to air. Linear openings were also understood. The next step was to test the material in making multidirectional connections. From the experiment a base of columns was erected and connections were made, it was observed that the connections made were mainly an arch. Rules of inclination were found from the tests. It was observed that the arches were breaking after a certain angle and to make them work the inclinations had to be between 750 and 1150.

Work The connections have to be inbetween the safe angles of 75-1150. The forms are very path oriented. Time Taken: 3 hrs Material Usage: Hard Mix = 900g Liquid Mix = 130ml

Conclusions Horizontal connections are more angular than linear. Multiple connections can be generated from the same vertical support Strong base layer of columns is required.

59


CHAPTER 6. POSSIBILITIES. NO FORMWORK

Conclusions From the experiments rules of growth and rules of inclination were understood. The material only works if these rules are followed. Openings in the form help in decreasing setting time of the material. Multiple forms are possible if the rules and path of spray are observed while printing.

60


61


CHAPTER 7 PROGRAM


CHAPTER 7. PROGRAM

“ INPUTING THE PARAMETERS TO OPTIMISE THE STRUCTURE..�

Rules After understanding the basic rules on which the material grows, computer simulations were required for generating dynamic forms which were based on principles of growth observed during the experiments. By simulating the growth patterns of the materials the structures which are generated can be optimised and a certain control over the growth can be achieved. In building a physical model parameters like loads, self weight, environmental conditions come into play and it is difficult to predict the final outcome of the process by assumption. A computer simulation can help in this regard. By inputting the parameters which effect the material behaviour a wide range of forms can be generated which work with the material and give an output best suited for material growth. The physical experiments take time to develop, by using computer simulations it can be easily understood if a certain method of working with the material works. 15 - 30 mm

6 - 15 mm

Printing ath p

120mm

Printing ath p

4 - 6 mm

30 mm

60 mm

Printing ath p

63


CHAPTER 7. PROGRAM

Analysis of form . According to material proprieties. The process required to do the analysis of the form and generate an output is purely dependent on the rules learnt during the manual experiments.

Steps Involved • • • • •

Selecting the basic geometry. The code analyses the geometry. Generates points based on rules of growth Connects the points with lines. Generates toolpath on the lines showing how the nozzle has to move.

The process needs to be simple as the more conditions involved the less the material behaves as it wants to.

External Parameters Sunlight Load Applied Self Weight

Granular materials


Optimization Once the basic geometry is generated it undergoes a series of tests to optimise itself based on load distribution. Geometry shifts and corrects itself so that the final form which is generated fulfills the rules of growth as well as is structurally optimised.

Rules of Growth Different heights of columns require different tool paths. Height Type Toolpath 0-30mm column Straight vertical line 30-60mm column Spiral path 60-120mm column Triangular spiral path

°

45 °

45

45 °

gth

gth

Len

Len

h Lengt

30 mm

75°

60 mm

120mm

90°

75°

75°

90°

90°

The safe angle at which the connections grow are between 75-1150. There is a possibility of inclining the columns more but decrease in angle to the horizontal also decreases the length of the connection which is directly proportional to the drying time of the material. ie: the more inclined the angle the more time the connection will take to dry and the length of the connection will also be less.

0° 0°

Inclanation rules

65


mm004

Rhino form

Bounding box

Simulation

Division into lines

Optimisation

According to loads

Result

Built manually

mm05

5

mm

002


Rhino form First step was the creation of a simple form - bounding box. To start it was decided to use a simple rectangular shape.

CHAPTER 7. PROGRAM

SIMPLE BOX

Simulation The script generates random points in the bounding box, connects them, eliminates ones by the factor of angles and distances.

Optimisation After the program optimises the form according to the loads and creates the path.

Result The result looks very similar to the simulation. It is structurally strong and stable.

67


Rhino form

Bounding box

Simulation

Division into lines

Optimisation

According to loads

Result 68

Built manually


Rhino form First step was creation of a bounding box. We wanted to explore the material on it’s edge, that is why we decided to make a tree.

CHAPTER 7. PROGRAM

EXPLORING MAX

Simulation The script found the lines of the way the material had to be deposited.

Optimisation After the program optimises the form according to the loads and generates the path.

Result It was discovered that it is possible to make a network of almost horizontal connections but it takes more time.For example the real world application for this system could be a bridge.

69


CHAPTER 7. PROGRAM

Conclusions Simulation and optimisation are very important steps as they give a huge possibility of forms which can be generated by material and the machinic process. The simulation required for the process is a mathematical simulation which generates the growth of the network. A material simulation was not required as the physical experiments gave the rules of growth. The generated forms are not only material specific but they compliment the input form.

70


71


CHAPTER 8 ROBOTIC ARM


CHAPTER 8. ROBOTIC ARM

“WHY DO WE NEED TO MAKE AN ARM?..�

Explanations As precision and efficiency are important , also as our system requires solar and heat exposure it can work in conditions not comfortable for humans it requires a robot to deposit the material. One way was to make a CNC frame, but in this case the possibility of multidirectional spraying would be lost. Therefore the best solution was to use a robotic arm. The other reason of choosing the robotic arm instead of CNC frame is that it has less dimensional constraints and unlike CNC frame it can create objects exceeding its own size. Furthermore the arm can be connected to chain gears or other driving mechanism which would increase its maneuverability and consequently make the printing process faster and cheaper. To prove the concept of robotic arm the working prototype was developed. A 5-axis robotic arm was fabricated in Fab Lab Barcelona and tested on site with the Stone Spray system. The prototype weights 10 kg which makes it easy to transport. Experiments done with the prototype showed that it is a very efficient solution for the given aim. The optimization script was updated that it converted resulted structural lines into a G-Code. The G-Code afterwards was sent to the arm prototype which in its turn encoded it into motor movement and actuated the motors.

73


Counterweight

Elbow transmission

Shoulder

Arm motors Nozzle

Shoulder motor

Processing core Shoulder transmission

Rotating base

Robotic Arm

Scheme of the arm 28

eg 5 d rees

360 d

rees eg

Robotic Arm Photo

Program

Scrinshot

180 d

s ree eg

135 d

rees eg

ees egr 0d

18


CHAPTER 8. ROBOTIC ARM

Robotic arm prototype The arm prototype has 5 axis of freedom, three lower joints are actuated by stepper motors and two final joints by servomotors. To decrease the load on the motors counterweights were implemented. Moreover to improve precision the stepper motors were enhanced with gear transmission system that as well facilitated their work. The level of precision achieved was very significant - one degree was divided into 100 steps. The motors were controlled with one Arduino UNO board and three Easydriver shields. Furthermore three potentiometers were used to encode the actual position of the arm, send it back to the computer for visualisation and also to protect arm from self collision. As the distance to the existing surface is crucial during printing process a distance sensor was implemented to the end point of the arm, the information from the sensor adjusts the predifined path of the nozzle.

Attachments and load bearing The robotic arm has the sand and liquid mix tubes connected to its end point. Flexible plastic tubes were used for this in order not to limit the rotation angles. Though, due to transmission system the arm can bear loads up to 3 kilograms at its end point it was decided to place sand and liquid containers aside from the arm to facilitate the refilling process and to increase the speed of movement.

Robotic arm software The software that controls the robotic arm was developed with Processing language. It visualises the actual position of the arm and the path that should be followed. The program has a manual control mode when arm is positioned by operator (used to set the start point). As well there is the automatic mode that actuates the motors accordingly to the G-Code text file (created by optimisation script).

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Simulated shape Stool

Optimized shape Path

Working process Robotic arm

Result

Stool without support


Description This model was meant to replicate the stool, done with the use of formwork in the previous experiments.

CHAPTER 8. ROBOTIC ARM

CHOREOGRAFY OF ROBOTIC ARM

Optimisation The program optimises the form according to the loads and generates the path.

Tool path The script converts the optimised lines into a g-code that is fed to the robotic arm.

Result The form of the final stool resembled the shape of the sample done with formwork. Although due to different structural parameters the results were completely different.

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Result 1

With wires

Result 2

No support structures


CHAPTER 8. ROBOTIC ARM

COMPAIRE CHAIRS Result 1 Stool made with the use of formwork. Dimensions: 300x300x300

Result 2 Second chair. Made using the path from the simulation code by our robot-arm. Dimensions: 400x400x400

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CHAPTER 8. ROBOTIC ARM

Conclusions The most important conclusion is that in order to create structures with Stone Spray system the user is not required to buy high-cost professional robotic arms, one can just fabricate a cheap self-made arm based on the prototype that was produced during this research. This arm would not just cost less, but also use less electrical power and be more transportable. This makes Stone Spray a very accessible system that can be used by any interested person. The other issue that appeared after the arm testing is that the material behaviour is so complex that it can’t be described with a simple G-Code, to the contrary elaborate sensor systems are required to correct the movement of the arm. Though the material never assembles in the same way due to different factors, artificial vision is needed to encode the printed shape, evaluate it and change the movement according to the differences between the it and the given 3d model.

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CHAPTER 9 PROPOSALS


CHAPTER 9. PROPOSALS

“BEING A NETWORK SYSTEM IT HAS THE ABILTY TO FILL SPACES”

Future Understanding the material behaviour its advantages and disadvantages the material has a lot of architectural applications. Being a network system it has the ability to fill spaces . The multidirectional nature has the property of building on existing forms and structures.

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Bridge

Multidirectional spraying

Shelter

Multidirectional spraying


CHAPTER 9. PROPOSALS

Architectural proposals Bridge Due to the multidirectional nature of material distribution and the spray technique, understanding its load properties, the system can be used to construct small-scale bridges.

Canopy The primary material for the process is a locally available material. On site shelters can be constructed using the system.

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CHAPTER 10. HOW TO?


CHAPTER 10. HOW TO?

“IT IS VERY EASY TO MAKE A NOZZLE...”

Make your own nozzle It is very easy to make your own nozzle. You don’t need any special knowledge or expensive equipment. All the materials can be found at a hardware store. Basically you can change some of the elements, but, experience shows that it is more effective to use transparent tubes for material feeders and flexible transparent tubes for the connection to the end point of the nozzle. In this case it would be easier to find the problem in case of a clog. Another suggestion would be to carefully filter the materials - both the hard mix and the binder. Be very accurate while connecting the elements, you have to be sure that the nozzle is completely air-tight, otherwise it could be dangerous to use it with pressure.

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Connection to compressor

Sand container

Level of sand

PP syringe

Compressor

Connection of PP to nozzle

Nozzle end

Nozzle 3

2 jet sprays

Connection to compressor

Sand container

Plastic tube - better transparent one

Connection to sand tube

Plastic holders for tube

Diagram

Pushing solidifyer

Solidifier container Diagram

Tube to nozzle

Connection of Syringe and Tube


CHAPTER 10. HOW TO?

Sand container A plastic tube of 40 cm length and 6 cm diameter. It is better to use a transparent tube, so a clog can be detected. TIP: Be careful while gluing it with holders. You have to make absolutely air-tight tube, silicon would be a good material.

Solidifier container A syringe of 100 ml volume was used, as it was the biggest that could be found. You can use any other syringe but then you will face the problem of frequent refilling.

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Tubes to nozzles Photo

Nozzle Photo

Minimum lenth for normal result

100 mm

150 mm

250 mm

Syringes and tubes

200 mm Best result

Photo

Pipe to the sand container

Compressor Photo

Compressor


Tubes to nozzles It is better to use plastic transparent flexible tubes so in case of clog you will find it easily.

CHAPTER 10. HOW TO?

MAKE YOUR OWN NOZZLE

Nozzle Try to follow the given angle, as the jets have to be mixed very close to the nozzle end. You can laser cut these polygons to hold and rotate the nozzle more comfortably.

Syringes and tubes We recommend you to use the finest needles you can find - then the flow is the most straight and it mixes perfectly. You can file the tube for better sand flow.

Compressor The last and the easiest part. Just borrow a compressor from your neighbour and connect everything like it is shown on diagram 1.

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THANK YOU


THANK YOU

Dear friends, This book is a result of a 6 month work, which would be absolutely impossible without the team of amazing specialists, who were supporting us during the process and helping when we needed it. Thank you, Marta Male Alemany, for the time you have given us and for your drive. We had a great time and because of you we were trying to push project forward more and more. Your ideas and critics were guiding us through when we were stuck. Thank you, Jordi Portell, for being with us in the most difficult moments. We always knew that in any case we could address our questions to you and you would be the one we could rely on in any time. And thank you for tolerating us during ups and downs. Thank you, Miquel Lloveras, for your irreplaceable references, which influenced the project a lot, they were a great source of inspiration. Thank you, Santiago Martin, for giving us another point of view regarding the project. And for introducing us to advanced softwares that will really help us in the future. Thank you, Guillem Camprodon , for the world of Arduino you opened to us, for the willingness of sitting with us on the code during several hours till finally it works. Without you it would be impossible to finish our robot and make it working. And, of course, thank you everyone for the critics we got from you, your ideas, your interest and your energy. It was an amazing time, and we have to say that it is incredibly hard and sad to say goodbye now. It could be great to continue working with you on this, or any other project. And you can always count on us. Thank you very much! Anna Kulik, Inder Prakash Shergill, Petr Novikov

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Stone Spray Project  

This book describes the additive fabrication research project that is called Stone Spray Project. It was done by Anna Kulik, Inder Prakash S...

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