Bamboo-Bam Summer School (FSS4 - 2021)

BAMBOO-BAM

ABSTRACT

This workshop was held with the participation of 42 students in 6 groups. 13 instructors helped them through the research and development process within four months.

During its process, the workshop tried to cover five major research areas: material studies, sustainability, computational design, form-finding, structural design, and digital fabrication.

These disparate fields demand a diversified set of skills, abilities, and experiences. We had instructors and partners from various institutions and backgrounds who willingly offered to share their talents and expertise to ensure that we could cover the topics to the extent required for a workshop.

CHAPTER 1: STUDY

Bamboo Sports Hall by Chiangmai Life Architects and Construction

Materiality

A team was tasked with researching bamboo as a natural, non-standard material, its qualities, applications, and construction possibilities.

Material Hunting

Following that, we conducted a market survey to determine the sorts of bamboo available. We identified four varieties and conducted a preliminary investigation, evaluating their quality, geometric and mechanical features, and workability, among other characteristics.

Vinata Bamboo Pavilion / VTN Architects

Vo Trong Nghia Vietnam bamboo resort

We also attempted to follow the BS ISO recommendations for bamboo grading. Finally, a native bamboo species known as ‘Kheizaran’ was chosen above the others.

Raw Iranian Bamboo (Kheizaran)

Raw Thai Bamboo

Flamed Iranian Bamboo (Kheizaran)

Flamed Thai Bamboo

02 SYSTEM

At the time, research into various systems for freeform grid shells was also proceeding. Despite their inherent differences, each of these systems was considered a viable direction for our workshop. This section of the study was designed to provide sufficient information for the upcoming phase of system design.

Bamboo Lashing Techniques

03 FORM-FINDING

Two groups were tasked with researching various form-finding methods. They presented a brief explanation of the fundamentals of each method, as well as a number of example projects constructed employing these methods. They also looked into the available tools and plugins for each. One Grasshopper code for each method was prepared to be shared and readily tested by other students.

CHAPTER 2: DESIGN

In a series of brainstorming sessions, various systems were proposed until a handful of them were shortlisted.

Evaluation Criteria

- Visual elegance

- workability

- Structural Performance

- Durability

- Cost

1. Polyhedron

2. Nexorade

The shortlisted systems were then prototyped, with the fabrication method for each being investigated. We undertook an evaluation procedure based on several criteria to determine the benefits and drawbacks of each system. We chose the final of these four options and proceeded with it.

Form-Finding tool development

On the other hand, everyone was encouraged to participate in form design, either by using the previously taught form-finding tools or by creating freehand designs if they were interested.

There was no predefined path, which meant that the workshop was guided by the participants’ interests. Following extensive editing and discussion, thirteen entries were shortlisted. The final form was then determined by popular voting.

CHAPTER 3: FABRICATION PREPARATION

After the form design phase, the BIM modeling starts.

Goals of this part was:

Visualizing the design Alternatives (with details: LOD

400)

Clash detection prior to fabrication

Extracting Fabrication Data (shop data & Estimations)

The modeling of a freeform structure is usually complicated. Some of the most difficult issues in this project were determining the optimal node size and proper node orientation in 3D space. Another challenge with freeform structures is the distinct shape of each element. These complexity required a unique modeling procedure.

we developed a “digital design workflow” in a parametric modeling platform known as “grasshopper”. This digital workflow fully automates the modeling process and delivers the required outputs in a timely manner.

6. Generating 3D Node (on the Plane)

2. Node’s Normal (Average of Neighbor Face Normals)

5. Adjusting Node’s Plane Elevation

1. Initial Mesh

4. Trimming Mesh Wires (Based on Node’s Size)

7. Generating Bamboo Axes (by Adjusting Mesh Wires)

The workflow starts with getting two general inputs from the user: first, the wire mesh generated during the form design phase, and second, some numerical inputs about bamboo, CNC machine, Bolts and nuts, and node design preferences.

9. Blending Both Handle’s Ends

12. Adding Handles’ Tags (Based On Node and Pockets’ Tags)

15. Adding Bamboo Tags (Based on Handles’ Tags)

8. Generating 2D Handles’ Ends (Node and Bamoo Part)

11. Adding Node’s Tag and Pockets’ Tags (Counter Clockwise Order)

14. Adding Screw, Nuts and Washers (Bamboos and Handles)

10. Generating 3D Handles and Subtracting Screw Holes

13. Adding Schematic Bamboo Pipes

After collecting and interpreting these data, it generates a completely comprehensive 3D model with labels for each element. As a result, it can be utilized as a coordination model during the assembly process.

The second output is the shop drawing of the nodes and handles. These parts will be milled from plywood sheets with a 3 Axis CNC machine. Also, the shop data of bamboos is delivered. This data is used to saw and drill bamboo with a rotary CNC machine. The final output is the numerical statistics about the BIM model, such as element count and length.

CUSTOM DIGITAL FABRICATION TOOLS

For the bamboo poles, we understood they would need four bolts at each end and not alighned to one another to connect to their respective joints.

Three-axis CNC milling machines already existed that could drill vertically through the bamboo poles. Our poles couldn’t be rolled due to the fact that the drilling was only going one way. A rotary axis that was not affordable and might not fit our CNC bed had to be purchased or we had to design a custom one. We decided to go for the latter solution. The bed’s horizontal constraints were not a problem, but the bed’s limited height had to be taken into account.

The rotary consisted of three main parts. A gripper to grab the pole firmly in place while drilling and meanwhile align its center to the rotary axis. A rail and an adjustable wagon for different pole lengths. And a rotator to orient the pole at the right angle.

We decided to buy a low-cost 3-jaw concentric gripper for one end and 3D print a cone-shaped piece for the other end that would attach to a plywood wagon. It was built to go easily along the Y-axis on a rail, making it flexible to the length of the bamboo pole.

For the rotator, we built a harmonic drive, also known as a strain wave gear, using 3d printed and laser cut parts, ball bearings and a stepper motor along with An Arduino board.

With the rotary axis in place, We only needed the precise toolpath to drill the poles with our CNC milling machine and the correct angle to rotate the poles after drilling the first two holes after the rotary axis was in place.

The rotation angles of each pole are collected from the grasshopper BIM model and used to construct the Arduino program for each rotation.

CHAPTER 4: CONSTRUCTION

Workshop Instructors:

Alireza Mostaghni

Mohammadreza Matini

Tutors (Alphabetically):

Amirreza Ardakani

Yasaman Ashjazadeh

Javad Allahgholi

Hanie Omid

Mohammadhasan Baghershahi

S Alireza Behnejad

Sara Saghafi Moghaddam

Ramtin Haghnazar

Seyed Ali Derazgisou

Danial Keramat

Mehran Masoudi

Jonas hauptmann

Workshop Participants:

Nima Azarang

Fateme Ebrahimi

Amin Ahadi

Mahya Akhavan

Razieh Omid

Sepehr Beyhaghi

Arefe Paydar

Reza Taghavifard

Alireza Taghizadeh Makoei

Fateme Tavakol

Aysan Jafarzadeh

Hasti Jafar Nejad

Milad HasanAbadi

Parnian Hasanpour

Masood Heidarpoor

Ali Khodabakhsh Hesar

Marjan Khosravian

Nahal Doosti

Sana Rastegar

Aida Rafizadeh

Neda Rafizadeh

Zahra Rahbarinezhad

Dorsa Sadat Seyedi

Hessan Shafagh

Maryam Shahrezaie

Kiana Saberian

Seyedeh Gelareh Sanei

Sepideh Sedghimehr

Atousa Sarrafi

Sorour Tarighi

Amir Mohammad Azizi

Mobina Ali Babaei

Seyed Hasan Fatemi

Mahmoudreza Sheikhfenderski

Elnaz Ghara Ziaeddin

Fateme Ghotbi

Raha Sadat Kamravafar

Saman Keihanian

Mahsa Matin

Niusha Moghimi

Amir Najimi

Ali Nakhaee

Digital Craft House

BioDesign Research Group