ARC280 Study Notes

ARC280 – Modelling and Fabrication in Design

Class Agenda

  • Machine Techniques for Digital Fabrication:

    • Cutting

    • Subtraction

    • Addition

    • Formation

  • Design Strategies for Digital Fabrication:

    • Sectioning

    • Tessellating

    • Contouring

    • Folding

    • Forming

  • Case Study: FabPod

    • Provides an example from research and practice

Part 1 – Machine Techniques

  • Digital fabrication techniques can be categorized into four main types:

    1. Cutting

    2. Subtraction

    3. Addition

    4. Formation

  • Reference for the content: Dunn (2012)

1. Cutting

  • Description:

    • Cutting is the most accessible and commonly used method in digital fabrication. It involves producing flat components from sheet materials using a cutting header that follows digital design data.

    • This method is often referred to as "two-dimensional fabrication."

    • Key Quote: "There is a range of different cutting techniques…" - Nick Dunn

  • Types of Cutting Technologies:

    1. Laser Cutters (available at Daniels)

    2. Plasma Arc Cutters (NOT available at Daniels)

    3. Water-Jet Cutters (available at Daniels)

    4. CNC Machines (available at Daniels)

2. Subtraction

  • Description:

    • Subtraction involves methods that remove material from a solid volume, leaving behind desired features and components. The material is typically removed through a milling or routing process.

  • Process:

    • Two-Axis Machines: Use a drill bit that rotates along X and Y axes, subtracting a two-dimensional pattern of material.

    • Three-Axis Machines: Allow vertical movement along a Z-axis for volumetric subtraction.

    • Multi-Axis Machines: Enable more complex forms and surface features through additional axes.

    • Endmills: The type of cutting tools involved, which come in various shapes and sizes for milling applications.

  • CNC milling is a key method in digital fabrication that uses coded instructions to control the movements of machining tools.

Toolpath in CNC Machining

  • A toolpath defines the movement of a cutting tool, detailing location, speed, direction, and cutting depth.

  • G-code represents the instructions provided to a machine that directs the motors' movements, functioning as the programming language of CNC and 3D printing technologies.

3. Addition

  • Description:

    • Addition involves digital fabrication methods that build material in layers rather than removing it. This technique is often called "additive manufacturing (AM)" or "3D printing".

  • Rapid Prototyping:

    • A group of techniques used to quickly fabricate physical parts based on 3D CAD data.

    • Fused Deposition Modelling (FDM) is a notable technique within this method.

4. Formation

  • Description:

    • Formation reshapes or deforms materials using mechanical forces. Processes typically involve heat or steam to make materials pliable, retaining their new geometry upon cooling.

  • Thermoforming:

- Process where plastic sheets are heated, shaped with molds, and trimmed to create final products.

Part 2 – Design Strategies

  • Different strategies in digital fabrication discussed by Iwamoto and Dunn include:

    1. Sectioning

    2. Tessellating

    3. Folding

    4. Contouring

    5. Forming

1. Sectioning

  • Description:

    • A method that generates numerous cross-sections through a form, using profiles that follow lines of surface geometry.

    • Applies in architecture, reminiscent of shipbuilding techniques where object forms are defined by sectional cuts to facilitate material application.

  • Example:

    • One Main Office by dECOi Architects (2009)

2. Tessellation

  • Description:

    • Tessellation is the assembly of shapes that fit together without gaps, forming coherent planes or surfaces.

  • Impact:

    • Digital technologies have sparked renewed interest in tessellation due to their potential for creating variation and efficiency in manufacturing processes.

  • Example:

    • Works of M.C. Escher demonstrating geometric tessellation.

3. Folding

  • Description:

    • A technique that converts flat surfaces into three-dimensional forms, enhancing material stiffness and enabling self-supporting structures.

  • Structural Potential:

    • Folding increases self-supporting span and geometry effectiveness, offering new design dimensions.

4. Contouring

  • Description:

    • This technique reshapes two-dimensional surfaces into 3D by removing material in layers, akin to carving.

  • Materials such as stone, plywood, and gypsum board are typically used.

  • Example:

    • Elbephilharmonie Concert Hall

Summary of Techniques

  1. Cutting: Two-dimensional fabrication through removal processes.

  2. Subtraction: Removal of material to form desired shapes.

  3. Addition: Layer-by-layer building of materials, includes processes like 3D printing.

  4. Formation: Reshaping materials through mechanical force.

  5. Design Strategies: Sectioning, tessellation, folding, contouring, and forming defining fabrication processes.

Further Readings

  • Iwamoto (2009) - "Digital Fabrications: Architectural and Material Techniques"

  • Dunn (2012) - "Digital Fabrication in Architecture"