3D printer

A 3D printer deposits or solidifies material in successive horizontal slices to construct a three-dimensional object directly from computer-aided design (CAD) data. Unlike subtractive methods such as milling, which remove material from a block, additive manufacturing builds objects up from nothing, reducing waste and lead time on small production runs and prototypes.

The main industrial technologies differ fundamentally. Fused deposition modeling (FDM) extrudes thermoplastic filament through a heated nozzle, cooling it immediately to form each layer, typically 0.1 to 0.3 millimeters thick. Stereolithography (SLA) uses an ultraviolet laser to cure liquid photoresin layer by layer. Selective laser sintering (SLS) sinters powder particles, usually nylon or aluminum, with a laser beam. Powder bed fusion, binder jetting, and material extrusion each suit different materials, tolerances, and production volumes.

Accuracy, surface finish, and material properties depend heavily on technology choice and tuning. FDM achieves reasonable dimensional tolerance but leaves visible layer lines and is weaker perpendicular to the build direction. SLA produces finer detail and smoother surfaces but resin parts cure over time and may be brittle. SLS creates durable nylon parts without support structures, but powder handling is labor-intensive and recycling adds cost. Resolution ranges from roughly 0.05 millimeters on high-end SLA machines to 0.3 millimeters on entry-level FDM units.

Where 3D printing fits in production

Toolmakers use 3D printing to produce jigs, fixtures, and custom end-of-arm tooling without the cost and delay of traditional machining or injection molding. Engineers rapidly iterate on prototypes. Hospitals print surgical guides and anatomical models from patient imaging. Spare parts manufacturers create low-volume components on demand. The technology struggles where speed, volume, consistency, or load-bearing capability matter most. A CNC machine still outperforms additive manufacturing for production runs of thousands of identical metal parts.

Materials have expanded beyond early plastics. Industrial 3D printers now work with reinforced nylon, titanium, aluminum alloys, stainless steel, composite powders, and specialty resins. However, cost per part remains high relative to conventional methods for large batches, and certification and material traceability can be critical in aerospace and medical applications. The technology excels at design freedom: shapes impossible or prohibitively expensive to manufacture conventionally become routine.