ProtoCAM: Additive Manufacturing, 3D Printing and Rapid Prototyping.

Stereolithography (SLA)

In stereolithography (commonly known as “SLA” or “SL”), a 3D CAD drawing is turned into a solid object through the repeated solidification of liquid resin by a UV laser. Among the most common additive manufacturing techniques, SLA can produce cosmetically superior parts in as little as 1-2 days.

Our Stereolithography Work

About Stereolithography

Stereolithography (SLA) is one of the more versatile rapid prototyping technologies and goes by many names including SLA rapid prototyping, optical fabrication, photo-solidification, solid-free-form fabrication or solid imaging.

No matter the terminology, the process involves turning a three-dimensional Computer Aided Design (CAD) drawing into a solid object through the rapid, repeated solidification of liquid resin.

To create an SLA rapid prototype, a 3D CAD file is digitally “sliced” into horizontal cross-sections between 0.002″ and 0.006″ thick. These “slices” are entered into one of ProtoCAM’s advanced stereolithography rapid prototyping machines where an ultraviolet laser traces the first layer of the part on a metal plate submerged just below the surface of a vat of photo-sensitive polymer. Wherever the laser touches the liquid, it solidifies. Once the layer is traced, the plate sinks the thickness of a layer below the level of the liquid. The next layer is then built upon the previous layer. In this manner the entire part is built from the bottom up.

Watch an animation of SLA:

SLA vs. SLS

Stereolithography (SLA) is often compared and contrasted with selective laser sintering (SLS). There are several key differences between prototypes created with these two rapid manufacturing techniques. These include:

  • Turn-around time: SLA prototypes can be completed in as little as 1-2 days, with larger projects taking fewer than five.
  • Tight tolerances: SLA prototypes can achieve tolerances +/- 0.005″ (0.127mm) for the initial inch, plus an additional 0.002″ for each additional inch.
  • Surface finish: SLA prototypes typically have a cosmetically superior finish, unlike SLS prototypes, which are typically powdery and granular.
  • Small-batch: SLA is well suited for small-batch or small-lot manufacturing of prototype or end-use parts.

Typical SLA Use Cases

Aesthetic models Form/fit models Presentation models
Clear models Casting molds Click here to see available finishes.