Stereolithography (SLA)

What is Stereolithography Apparatus?

Stereolithography Apparatus is a form of 3D printing which involves a UV-sensitive resin that cures into 3D objects when a UV laser scans over it, drawing a pattern layer-by-layer. It is one of the older forms of 3D printing that 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 FFF).

Benefits of SLA over other processes:

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

  • Smooth surfaces (up to .025mm layer height)

  • Lower cost than industrial processes like PolyJet

  • Relatively quick (we offer 3 day turnaround time under normal circumstances)

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

  • Isotropic material properties once cured

  • Each layer, regardless of material cured takes nearly the same time

Drawbacks of SLA over other processes:

  • Higher cost than desktop FFF/FDM

  • Additional cure time required for many resins

  • ‘Messier’ than FFF/FDM due to toxic resin and IPA cleaning solution

  • Part must be ‘solid’ (can be hollowed out, but there are additional considerations for that)

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

  • Must use tree-supports which can leave ‘nubs’ (must be removed in post-processing)

  • Usually smaller build volume than most other processes

Formlabs Form 2