How to Turn Virtual Designs into Physical Objects
The following is from a very well designed page and explanation at the Advanced Civilisation site, at http://www.adciv.org/Virtual_designs_into_physical_objects
- 1 Introduction
"Some of the ways that collaborative designs created on a computer can be physically forged range from getting your hands dirty and crafting it yourself, to sending the design, or at least parts of it, as an electronic file to an increasing number of flexible computer-controlled manufacturing systems such as rapid prototyping or advanced multi-axis CNC machines that can accurately create parts in 3D in a variety of materials. What is illustrated in this section is that the world of atoms is starting to catch up with the world of bits in terms of ease of control and duplication"
Overview of Strategies
Material excerpted from http://www.adciv.org/Virtual_designs_into_physical_objects
Strategy 1: Making It Yourself
Craft the item yourself or in a group according to plans using your own skills and tools plus readily available 'off-the-shelf' components. 'How-to' step-by-step guides, sometimes with video, are increasingly being published on the internet for this kind of project.
Strategy 2: Local Custom Fabrication
Small-scale local engineering firms that will make custom items to order have always been around, often specialising certain materials and techniques.
Strategy 3: Contract Manufacturing
"A large group of people all wanting the same item to be made could get together and send the details of the design to a large-scale contract manufacturing and assembly company to make use of specialist facilities and economies of scale."
Strategy 4: Mail Order Machining
Online Custom Fabrication:
"eMachineShop  takes custom fabrication a step further in terms of ease of use. The US-based company supplies a fairly simple computer-aided design program that once materials have been assigned to the geometric forms an automatic bill of materials can then be calculated. When the user is happy with the design and the price, the information is sent over the internet to eMachineShop where the parts are fabricated using the appropriate computer-controlled machinery. The finished parts are then mailed back to the user.
A related company is Pad2Pad  that provides a similar service for the creation of printed circuit boards (PCB). They also provide free design software that has circuit error-checking and costing built-in. When the design is completed it is sent electronically to the company who then fabricate the PCBs and return by post. They do not currently populate the boards with electronic components." (http://www.adciv.org/Virtual_designs_into_physical_objects)
Strategy 5: Rapid Prototyping
"Rapid prototyping machines, sometimes called 3D printers, are now commonly used in the design and manufacturing industries for creating solid three dimensional objects straight from CAD models. Currently there are various limitations with these machines but in the near future the price will reduce rapidly, the number of different materials that can be used to make parts will multiply, the resolution will become steadily finer and the build-speed will increase. It is likely that these machines will soon be within the reach of ordinary people following a similar evolutionary path to computer printers. Mail order rapid prototyping services are already available." (http://www.adciv.org/Virtual_designs_into_physical_objects)
Strategy 6: Fabrication Laboratories
"Fab Labs are small scale workshops with modern computer controlled equipment such as...
- Laser cutters, plasma cutters and water jet cutters - to cut sheet materials such as plastic and metal
- CNC machines - computer controlled mills, lathes etc
- Rapid prototyping machines - 3D layered construction
- Printed circuit board milling machines
...giving the ability within one room to create just about anything from engines to electronic devices. The concept was developed at the Center for Bits and Atoms at MIT.
Commercial versions are now starting to spring too, see http://www.techshop.ws" (http://www.adciv.org/Virtual_designs_into_physical_objects)
Strategy 7: Automated Construction
"Computer controlled flexible manufacturing methods can even be applied to constructing buildings. Contour Crafting is a technique that has been developed by Behrokh Khoshnevis of the University of Southern California that involves building up the structure of the building in horizontal layers by squeezing out quick drying cement from a nozzle. By the time first layer has been drawn out, the first part to be laid will have solidified enough to take the second layer. This is much like the 'Fused Deposition Modelling' printing method but on a huge scale.
Walls of building constructed using these methods do not have to be straight, on either the horizontal or vertical axes, so complex organic curved and domed buildings can be made, perhaps mimicking biological structures.
Houses can be designed completely on computer, then the automated constructor gets to work with no human labour involved. Pipework and cabling could even be laid inside walls as they are being built."