Request A Sample
A Beginners Guide to 3D Printing: DLP, SLA, and FDM

A Beginners Guide to 3D Printing: DLP, SLA, and FDM

March 23, 2017 – By Nicole Dietz

For the past few years, 3D printing — also known as additive manufacturing — has empowered dreamers to turn their visions into reality. Everyday consumers hear the buzz surrounding 3D printing but have limited knowledge about the process.  For those looking to broaden their understanding of 3D printing, here is a guide to the three most common 3D printing processes.

FDM: Fused Deposition Modeling

In the world of desktop 3D printing, FDM is the go-to printing method users choose.  The broad choice of FDM printers at a wide range of price points and the relatively inexpensive filament rolls are why this method is so popular.  3D enthusiast can even build their own.  Like a hot melt glue gun, a spool of the thermoplastic filament slowly extrudes through a heated nozzle.  The extrusion nozzle lays down a thin line of the melted filament onto a tray in layers.  The process is ideal for printing simple objects that don’t require fine precision and smooth surface finish.  The process is not ideal for printing products that require a smooth finish and fine details.  Unfinished prints typically have a rough surface but can be sandblasted, smoothed, and painted.  These final steps needed to achieve the desired finish can remove the fragile design details desired in the original objective.


SLA: Stereolithography

SLA was the first commercially recognized 3D printing technique. The process works by exposing a tray of photosensitive liquid resin to UV light using a laser.   The laser traces each layer point for point, curing the resin into a solid form with each exposure.  The complex process directs the laser beam across the surface of the resin tray along the X-Y axes (build area).  A 3D file is supplied to the machine and instructs the laser to precisely target each point on the surface.  When the laser completes a layer, the platform that holds the previously completed layer is raised slightly, and the next layer is traced and cured.  This procedure continues until the object is finished.   The tracing process is time-consuming because only one point is cured at a time.  It also takes more time to print your design if multiple objects are created on the same print. SLA is known for producing accurate objects with a smooth surface finish. 


DLP: Digital Light Processing

DLP technology uses a sophisticated high-definition illumination system that exposes UV curable resin to UV light. First, a vat filled with the resin is placed inside the machine. The machine then reads a 3D file, and the build table lowers to allow a small amount of resin to be cured to it, one entire layer at a time. After one layer is cured the machine moves the object up by a fraction and cures the new layer to the previous one, creating a solid object. Each thin solid layer will continue to build on top of another. Because the light exposes the entire build table simultaneously, the printer can produce multiple objects in the same amount of time it takes to build just one object. The intelligent calculations of the DLP illumination system allow for greater accuracy than other 3D printers and deliver fine details due to the exceptionally precise technology.  DLP printers are praised for printing small intricate objects at high-resolutions across an entire build table without sacrificing print quality or surface finish.