Stereolithography (SLA)

What is Stereolithography?

Stereolithography is a form of 3D printing which involves a UV-sensitive resin that cures as a UV laser scans over it, drawing 2D patterns layer-by-layer, building the resin into a 3D model.  It was the first patented method of 3D printing and has only recently gained traction in the consumer market primarily due to more cost-effective scanning lasers and the popular Formlabs printers.

Why would I use this process to create a 3D part?

In general, SLA printing offers high-fidelity parts for cheaper than more commercial processes like PolyJet printing. SLA offers a decent option for purely aesthetic parts and even functional parts that require precision or isotropy (as opposed to anisotropy found in processes like FDM).

Benefits of SLA over other processes:

• High-fidelity (~ .01mm accuracy in X and Y directions for most cases)

• Smooth surfaces (down to 0.025mm layer height)

• Lower cost than industrial processes like PolyJet

• Large variety of resin materials  (see what we offer at ter.ps/papercut)

• Isotropic material properties once cured

Drawbacks of SLA over other processes:

• Higher cost than FDM

• Additional cure time required for many resins

• Models are printed solid (no "infill" like FDM processes) 

• No commercial options for multi-material in a single print

• Must use tree-supports which can leave ‘nubs’ of residual material (this can typically be removed in post-processing)

• UV curing required for post processing (more post processing time than FDM processes)

• Usually smaller build volume than most other processes