Types of 3D Printers for K-12 Makerspaces
While there are many 3D printing technologies on the market, the most common type of printers found in makerspaces use Fused Filament Fabrication (FFF) technology - sometimes referred to as the trademarked term Fused Deposition Modeling (FDM).
In FFF, plastic filament is pushed through a small hole in a heated metal nozzle. That nozzle is attached to a robot that can move the nozzle left-to-right (X axis), front-to-back (Y axis), and up-and-down (Z axis). The printer extrudes a layer of the model in two dimensions (X,Y) and then moves up a fraction of a millimeter to draw the next layer, continuing until you have a completed 3D object.
FFF printers use spools of thermoplastic filaments that have been specially formulated for use in 3D printing. Some printers require proprietary spools and have a varying selection of compatible materials.
In FFF, plastic filament is pushed through a small hole in a heated metal nozzle. That nozzle is attached to a robot that can move the nozzle left-to-right (X axis), front-to-back (Y axis), and up-and-down (Z axis). The printer extrudes a layer of the model in two dimensions (X,Y) and then moves up a fraction of a millimeter to draw the next layer, continuing until you have a completed 3D object.
FFF printers use spools of thermoplastic filaments that have been specially formulated for use in 3D printing. Some printers require proprietary spools and have a varying selection of compatible materials.
The most common plastic to use in makerspaces is PLA (polylactic acid), a plastic made from plant starches that is easy to print with, has a lower printing temperature, does not shrink or warp easily, produces the least amount of odor, and is available in a wide variety of colors and textures. However, PLA is not very flexible and prints can be brittle and break easily. PLA can "expire" if exposed to a humid environment for too long, becoming more brittle and difficult to print with. It is an excellent filament choice for expressive models, but may not be the best solution for creating mechanical parts.
Another good option is PETG (polyethylene terephthalate glycol-modified). PETG is strong, slightly flexible, and does not shrink or warp. It is not sensitive to moisture - PET is what most plastic bottles are made of! PETG prints at a higher temperature and usually requires the use of a release agent like glue stick to ensure it doesn't stick to the print bed.
ABS (acrylonitrile butadiene styrene) is a common plastic used in consumer goods that is strong and durable, but it prints at a higher temperature, smells like burning plastic while printing, and requires an enclosed printer (or very warm, controlled environment) to prevent warping. With PETG becoming more widely available, ABS is less of a good fit for general makerspace use.
More "exotic" filaments include things like flexible polymers, strong carbon-filled plastics, filaments with conductive metal additives, and plastics like nylon and CPE are available, but are often more expensive and difficult to work with. Some filaments are abrasive and may shorten the life of your printers' nozzles. Many materials need higher temperatures, heated or specially-treated build surfaces, or an enclosure to print properly. With all filaments, make sure the material is compatible with your printer.
Another good option is PETG (polyethylene terephthalate glycol-modified). PETG is strong, slightly flexible, and does not shrink or warp. It is not sensitive to moisture - PET is what most plastic bottles are made of! PETG prints at a higher temperature and usually requires the use of a release agent like glue stick to ensure it doesn't stick to the print bed.
ABS (acrylonitrile butadiene styrene) is a common plastic used in consumer goods that is strong and durable, but it prints at a higher temperature, smells like burning plastic while printing, and requires an enclosed printer (or very warm, controlled environment) to prevent warping. With PETG becoming more widely available, ABS is less of a good fit for general makerspace use.
More "exotic" filaments include things like flexible polymers, strong carbon-filled plastics, filaments with conductive metal additives, and plastics like nylon and CPE are available, but are often more expensive and difficult to work with. Some filaments are abrasive and may shorten the life of your printers' nozzles. Many materials need higher temperatures, heated or specially-treated build surfaces, or an enclosure to print properly. With all filaments, make sure the material is compatible with your printer.
Less common in makerspaces but increasing in popularity (and decreasing in price) are 3D printers that use Stereo Lithography (SLA) technology. SLA printers use a focused beam of light to harden a liquid resin in layers to build an object. While these printers can produce very detailed prints with complex geometry, the resin used is messy, expensive, and potentially hazardous if not handled correctly. SLA prints need to be washed in isopropyl alcohol before being handled.