The ABC's of XYZ's
The Cube from 3D Systems is one of the most popular consumer-grade 3D printers available. It's sold at Walmart and elsewhere for around $1299.
This is a time-lapse video of the Cube printing a napkin ring. The action is sped up roughly 60x the actual speed.
3D printers, like the cube, are fairly simple machines that manufacture objects using three axes. Here the print head is moved on the x axis, the printing platform is moved on a y axis , and the z axis moves the printing platform down in increments measured in hundredths of an inch as the object grows. Together these three axes allow printing material to be distributed onto the printing platform around a 3-dimensional space called the print or build area. The maximum size of objects to be printed are limited by the size of a printer's build area.
Consumer-grade 3D printers typically use plastic line as feedstock. The plastic is melted and sprayed out as microscopic particles at the print head. The object is built one layer at a time. The thickness of the layers determines the print or build resolution of the printed object. The thinner the layer - or smaller the z axis motion, the smoother the object.
This is a RepRap printer which is typically sold as a kit for around $800.
Objects to be printed are stored in files, and provided to a printer on a USB drive or SD card, through a cable connection to a computer, or over a wireless network.
Some printers print on a heated surface so that the object sticks. This RepRap printer has a significantly larger build area than the cube and so can print larger objects.
Rather than printing solid objects, hollow core supportive structures are used to save material costs.
Since these types of printers print in layers from the bottom up, it's impossible to print stalactite features since it would mean attempting to lay down material in thin air. For example, if these fingers were curled over they would present stalactite features. To get around this issue, support structures can be incorporated into the design and removed after the object is printed. Some objects can be flipped or rotated to eliminate stalactite features.
Primary purchasing considerations for 3D printers include build space, build resolution, supported materials, speed, maintenance and reliability.
What can I print?
Descriptions of objects and instructions to the printer are stored in StereoLithography files, better known as STL files. Consumer printers like the Cube typically come with a catalogue of STL files, some files are provided for free, for others you'll have to pay to download. 3D Systems calls it "creativity reimagined," but how much creativity is involved in downloading a file and printing it?
Makerbot provides a website named Thingiverse where users can upload STL files to be shared. Thingiverse contains thousands of objects to print in numerous categories. For example Household Items include a juicer, vase, coffee cup sleeve and cabinet shelves.
Another option for acquiring objects to print is to scan them. This handheld scanner from Polhemus is ideal for portable applications. Acquiring sequential scans of the entire surface of an object, allows the software to recreate the object in virtual space. Selling for several thousand dollars, these devices are typically used by professionals.
A stationary scanner captures high resolution 3D scans by rotating an object in front of the scanner. Once again, the software creates a composite of all the scans to store the object digitally. Once captured, the file can be exported as an STL file for printing.
Makerbot sells a consumer-grade scanner called the Digitizer for $799. Using the Digitizer, a hobbiest can scan a small object, edit the scan, and print the object to a Makerbot printer.
For the ultimate in creativity, 3D Modeling or CAD software can be used to create your own objects from scratch. Software such as Blender, Sketchup, Rhino, Maya and AutoCAD allow you to create and edit 3D designs. The learning curve on some of these packages can be steep, but the rewards are many. Blender is open source CAD software that is available to download for free. Jewelers are using CAD software and 3D printers to create jewelry with more detail and complexity than has ever before been possible.
In the next video, you'll learn how 3D printers are being used to print much more than just plastic doodads.