Process comparison · Process and manufacturing decisions

FDM or SLA: choosing for functional parts and precision models

SLA polymerises liquid resin with light and achieves fine detail and smooth surfaces. FDM extrudes thermoplastics and offers a broad range of engineering materials. Required function matters more than visible resolution.

In brief

SLA often suits fine models, small channels and high-quality visual samples. FDM often suits larger, loaded and material-specific functional parts. Manufacturer data for the actual material remains decisive.

Detail and surface

Resolution is only one part of component quality.

FDM
Visible layers and roads; nozzle geometry limits small details
SLA
Fine detail and smooth surfaces; consider support marks and cleaning

Material and use

Resin labels and thermoplastic names are not directly comparable material classes.

  • Check temperature, media contact, UV and sustained load against actual datasheets.
  • Post-curing can influence SLA properties and dimensions.
  • FDM properties depend strongly on orientation and layer adhesion.

Decision questions

The right choice starts with the application, not the process.

  • Is surface or mechanical function more important?
  • Which media and temperatures occur in reality?
  • Is the sample only for evaluation or permanent use?

Technical basis

Frequently asked questions

Is SLA always more precise?

SLA can show finer detail, but part accuracy also depends on geometry, supports, cleaning and post-curing. Precision must be assessed at the relevant feature.

Are SLA parts suitable for functional tests?

Yes, if the actual resin suits the load and environment. The word resin alone says nothing about sustained load, impact or temperature.

Which process suits large parts?

FDM is often economical for large volumes. The actual limit depends on build space, splitting, surface requirement and warpage.

Can SLA serve as an injection-moulding prototype?

Yes, especially for form, surface and detail review. Mechanical transferability requires separate comparison of resin and production polymer.

How should quotes be compared?

Use identical geometry, quantity, finishing, inspection features and delivery date. Otherwise you are comparing scope rather than process.

Apply the requirement to a real part

Send the CAD file, quantity and service conditions. We review manufacturability, material, orientation and useful inspection features and prepare a quote.