3D Printers - Explained and Explored

Introduction

If you really want to express your creativity and impress your friends with high-tech wizardry then consider shopping for a three-dimensional (3D) printer. Already well-established in sophisticated design studios, the price of a few basic 3D printers has dropped to under $5,000 opening them to home use.

What are 3D Printers?

Using what may seem like wizardry, a 3D printer can really create any three-dimensional object, no matter how complicated, that you can design in a computer. The underlying process is quite simple. Objects are built up inside the printer, thin layer upon thin layer as a printer makes repeated passes, following a sliced-up blueprint provided by the computer. The 3D form grows upwards, at a rate of about 5cm (2 inches) an hour, until it is done.

Different manufacturers have different approaches. Two leading companies, Z Corp and 3D Systems, offer a choice between powder and polymer as the material from which the object emerges. In either case, an inkjet printer creates the shape of the object, either by adding a glue to the powder, or by pumping out fine drops of polymer that are then cured by an ultra-violet lamp.

The photo below is an example of replication of a real object by means of 3D scanning and 3D printing. The gargoyle original on the left was digitally copied by using a 3D scanner and the produced 3D data was processed using MeshLab. The resulting digital 3D model, shown in the screen of the laptop, was used by a rapid prototyping machine to create a real resin replica of original object (right).

(Image by ALoopingIcon on Wikimedia)

Advantages of 3D Printers vs. Rapid Prototyping Machines

Rapid prototyping (RP) has been used by the aircraft and automotive industries for years, but now it is finally becoming accessible to consumers. 3D printers have some generally-agreed-upon defining characteristics:

• 3D printers can be used in an office environment - they are small and are usually designed to use materials in cassettes or other enclosed means.
• 3D printers make smaller parts - Most 3D printers are limited to making parts that will fit roughly in a cube 8 inches on a side.
• 3D printers are easy to use and cheaper to maintain (compared to RP machines).

The reasons for using a 3D printer are fundamentally the same as for using RP: to verify a design, create a prototype, share information across distances, make a one-off part or proof of concept, and many others. Only now 3D printers make it more affordable.

3D Printers Priced at $5000 or Less

Desktop Factory is accepting reservations for an additive fabrication system which it will start delivering in early 2009 with a price of less than $5,000. The technology uses a scheme which transfers partially melted, 0.010 in thick, powder layers to the top of a build stack using a drum. Selective exposure is by halogen light source and the parts are said to be quite robust, although they may lack the finer detail and finishes available from other technologies.

Koba Industries provides kits for fab@home machines priced in the range of $3,000. It also sells major machine structural part kits for those wishing to procure their own electronic and mechanical components or to experiment. An (almost) completely assembled version of the machine can be purchased for about US$3,600.

Fab@Home is an open-source project to design, develop and manufacture an inexpensive syringe-based additive fabrication machine and related software. The components to build the device can be had for as little as $2,500 and a variety of materials can be used for building, from silicone to chocolate. The project is led from Cornell University, but there are participants from all over the world. The hardware designs and software on this website are free and open-source. Once you have your own fabber, you can also download and print various items, try out new materials, or upload and share your own projects. Advanced users can modify and improve the fabber itself.

RepRap is short for replicating rapid-prototyper, an open-source 3D printer design project initiated by Adrian Bowyer at the University of Bath (UK). RepRap uses robotic thermoplastic extrusion similar to fused deposition modeling at present, but ceramic, metal and other materials may also be possible at some point. The ultimate intent of the project is to eventually produce a machine which can make copies of itself. Parts kits and individual items are now available from these sources:

• Bits From Bytes (UK) Sells complete kits of mechanical parts for about $600.
• RepRap: Store US vendor selling mostly parts and sub-system kits.

Online Services

If you're intrigued by this new technology but unsure about investing in your own 3D printer, there are online services that will print your 3D models and designs for you.

A new online service in the Netherlands called Shapeways aims to bring customized manufacturing to the masses by allowing consumers to submit digital designs of products that are then printed, using 3-D printers, and shipped back. Users submit their design in digital form, after which Shapeways' software checks it over to ensure that it can be made. Shapeways then passes the design to its production line of polymer printers, delivering the tangible object within 10 days of ordering, with prices typically between $50 and $150.

Children can design a figure using SolidWorks' Cosmic Blob software on their home PCs, then go to a Web site run by 3D printer-maker Z Corp. and order their figures to be "printed" for $25 to $50. Figureprints.com can recreate your favorite World of Warcraft® character as a fully detailed 3D replica rivaling the beauty of any miniature figure ever made for $100 and up.

Summary

Ultimately, many tech industry insiders think consumers will have these printers at home as the technology improves and prices continue to decrease. One estimate predicts the number of 3-D printers in businesses and homes will grow 75 fold by 2011. The idea is that people will pay a nominal amount for blueprints and then download them, in much the same way that music is shared over the Internet now.

Add a 3D scanner and you will be able to reproduce real objects in just a few minutes. Then the real fun of 3D printers will come alive as ordinary folks at home feel free to let their creativity run wild. If you can imagine it, you can make it!