3D printers, sometimes known incorrectly as “3D printing machines”, are additive manufacturing machines that specialize in making custom parts with accuracy.
As the name suggests, 3D printers add material, layer-by-layer, to form a 3D object. Virtually any geometry can be 3D printed, including some that cannot be made with other traditional processes.
The three most popular forms of 3D printing are fused deposition modeling (FDM), stereolithography (SLA), and selective laser sintering (SLS). SLS is primarily an industrial process, while FDM and SLA cover the gamut from high-end industrial manufacturing to simple desktop units.
3D printers are classified as “additive” for a reason. Unlike CNC mills, which have to remove material using rotary cutters, additive processes build up objects one layer at a time. Specialized software “slices” a 3D model into layers as thin as .05 mm for fused printers, and as thin as .01 mm for SLA processes. These layers are then deposited by the print process, slowly building up a 3D object.
FDM was the first technology to properly reach the hobbyist level, and it’s been continuously improved for the past decade. Perfectly good printers can be had for under $200, while larger print volumes and tighter tolerances drive prices up to several thousand dollars.
FDM printers are nearly unlimited in capacity. Besides the mundane, folks have printed cars, human organs, and even an entire house. On the other hand, if tiny details are what you need, look to the oldest 3D printing process…
Like an FDM printer, SLA prints its objects from the bottom up. But unlike FDM, which prints objects from the plate upwards, SLA most often prints from the plate downwards. This difference and many more make FDM and SLA rather different processes
There are many parts, and each one plays a crucial role in the printing process.
The way it works is that a spool of filament is loaded into the 3D printer and fed through to a printer nozzle in the extrusion head. The printer nozzle is heated to the desired temperature, whereupon a motor pushes the filament through the heated nozzle, causing it to melt. The Slicer software running on the computer connected to the 3D printer translates the measurements of an object into X, Y, and Z coordinates and controls the nozzle and the foundation follow calculated route during printing.
The printer then moves the extrusion head along with specified coordinates, laying down the molten material onto the build plate where it cools down and solidifies.
Once a layer is complete, the printer proceeds to lay down another layer. This process of printing cross-sections is repeated, building layer-upon-layer until the object is fully formed.
Depending on the geometry of the object, it is sometimes necessary to add support structures, for example, if a model has steep overhanging parts.
Overall printing time depends upon size and complexity of your model.
Small objects can be completed relatively quickly, while larger, more intricate parts need more time.
When the printing is finished supporting materials can readily be removed either by putting an object into a detergent and water solution or snapping the support material off by hand.