Fabrication

Peter Silver, William McLean

• Publisher: Routledge
• Year: 2008
• Print ISBN: 9781138165304
• eBook ISBN: 9781136403880
• Topic: Architecture
• Subtopic: Architecture General

Packed with stunning images this is an indispensable visual guide illustrating and explaining current fabrication processes and material transformation. Providing a documentary of an eclectic range of fabrication techniques, this is the ideal reference for designers who wish to learn more about the materials and current technologies in material production available to them. Featuring the work of 12 fabricators based in the UK, the case studies displayed range from manufacture of complex wire rope, the processes of metal spinning, large-scale composite casting, to computer controlled sheet steel fabrication. With a full knowledge of how the materials are transformed, this book provides readers with a greater ability to employ material processes for their own designs and to better understand material fabrication. This is a book that provides information on contemporary technology and design inspiration in abundance.

1

Sheet Metal

Fig 1.0 Sheet metal

Fig 1.1 Metal sections

Fig 1.2 CNC laser

Sheet Metal

John Dent Engineering, Isleworth

Sheet Materials

Sheet materials come in various types, from mild steels to timber and plastics, and with varying degrees of thickness. If designers need sheet materials to be cut to size with precision, or if multiples are required, specialist fabricators provide the tools and expertise necessary for their production. Such fabricators will also have machines for folding sheet metal into complex shapes and will be able to finish (weld, polish, paint) products in a variety of ways.

Laser Cutting

CNC (Computer Numerically Controlled) laser cutting is a process in which a shape is cut from sheet material using an intense laser beam that cuts by melting the material in the beam path. The process is particularly cost-effective for prototyping and short runs, since no physical tooling is needed and the process can accept almost any geometric shape. Lasers have interchangeable optics for different materials and depths of cut. Lasers work best on materials such as carbon steel - an alloy of iron and carbon (2%) or stainless steel - a corrosion resistant alloy of steel and chromium (10.5%). Metals such as aluminium and copper alloys are more difficult (slower) to cut by laser due to their ability to reflect the laser light as well as absorb and conduct heat - these materials require more powerful lasers.

Fig 1.3 CNC cutting bench

Fig 1.4 CNC Laser-cut, 8mm sheet steel

Fig 1.5 CNC laser-cut, 10mm sheet steel

Fig 1.6 CNC laser cutting 5mm plastic sheet

A laser can cut through a 1m long, 10mm thick, steel panel in around 30 seconds, but the thicker the steel the larger the curve that will form when cutting around corners. CNC lasers are housed in x/y/z-axis gantries that can be programmed to cut from CAD drawings like a large plotter. They are accurate to within 50 microns and parts remain flat.

Fig 1.7 John Dent Engineering

Fig 1.8 Press brake tool head

Fig 1.9 Tool head showing fold profile

Fig 1.10 Tooling library

Maximum material cutting capacities are:

Mild steel - 12mm

Stainless steel (clean cut) - 3mm

Stainless steel (oxygen cut) - 12mm

Aluminium - 4mm

Brass - 2.5mm

Woods and Plastics - 30mm

Maximum sheet size - 3000mm × 1270mm

Maximum weight - 250kg

Folding and Finishing

Once they have been cut into shape, malleable materials (i.e. those like sheet metal that can be folded without loss of structural integrity) can be formed into complex, three-dimensional shapes by multi-axis folding machine. An 80 tonne press brake can fold sheet metal up to 10mm thick.

Fig 1.11 Eight-axis, full CNC press brake

Fig 1.12 Sheet metal, cut and folded

Fig 1.13 Sheet metal, cut and folded

Fig 1.14 Hand finished folde...

Table of contents

• Front Cover
• Half Title
• Title Page
• Copyright
• Contents
• Author's Note
• Foreword
• Introduction
• 1 Sheet Metal
• 2 Softwood Timber
• 3 Glass-Reinforced Plastic
• 4 Tensile Steel
• 5 Steel Sections
• 6 Limestone
• 7 Terrazzo Concrete
• 8 Membrane Fabric
• 9 Float Glass
• 10 Tensile Yarns
• 11 Cast Metal
• 12 Spun Metal
• Glossary of Processes
• Company Information
• Sources
• Acknowledgments
• Authors
• Index