The X-Tiles Video Series: Our Most Popular 3D Printing Processes, Pt. 2

The video below takes a look at selective laser sintering (SLS) versus fused deposition modeling (FDM) and when to choose one over the other. Each has a distinct cosmetic outcome: SLS tends to have a fine sugar cube-like texture while FDM shows distinct layers from the melted filament. FDM, however, has a much higher variety of material and color stock as well as a much larger print area.

Another noteworthy decision factor of FDM is layer height. For all prints under 14” in length, Xometry uses 0.010” layers as a standard. When building larger prints using the Stratasys Fortus 900 MC platforms, Xometry uses 0.013” layers. These layer heights may seem tiny, but on gradual contours, you can see a visible difference. Check out the video below for a quick comparison of FDM and SLS layer heights!

SLS is often confused with SLA but they are very different processes. SLS fuses nylon powder into cross-sections of a part via a laser. Without the need for support structures, SLS can build many parts at once, which enables great pricing. However, SLS does not offer as high of a variety of options. And while the surface finish of SLS parts is good compared to FDM parts, other processes like SLA can achieve an even better-looking part. SLA, or stereolithography, makes parts from a liquid resin that is cured with a UV-laser or UV-DLP projector. The surface finish of an SLA part tends to be smoother and have a plastic-feel like injection molding. It should be noted that SLA resins are not thermoplastics, and instead, Xometry offers a variety of engineered materials to behave like popular plastics. These include polycarbonate, polypropylene, nylon, and ABS. There is even a highly stiff ceramic composite resin great for making fixtures and molds. The video below shows some of the strengths and trade-offs, between SLS and SLA.

Carbon Digital Light Synthesis™, or DLS, builds a 3D model by curing liquid resin with a DLP projector in a continuous process. Continuous printing is unique to Carbon’s platform and gives part features isotropic properties. Additionally, materials can thermally cure to give excellent end-use properties. DLS has two elastomers, EPU 40 and SIL 30. Both of these are urethane-based and very robust. PolyJet can also print in rubber-like materials and boasts the ability to make a digital matrix to create overmolds and simulate different Shore A values. The video below shows when and why you may choose one over the other. DLS boasts end-use performance and scalability, whereas PolyJet boasts rapid-turn “feels-like” prototypes.

If you haven’t heard of Carbon DLS, this X-Tiles video is a great start! In it, I go over each of Xometry’s DLS material options, the process’s key properties, and how these parts may be used.