When it comes to 3D printing, the technology you choose matters as much as the material. FDM (Fused Deposition Modelling) and SLA (Stereolithography) sit at opposite ends of the spectrum in how they work, what they produce, and what they cost. Both earn their place in a serious manufacturing workflow.
We run both technologies under the same roof in Perth, so we have learned exactly when to reach for each. The Q and A below covers the questions clients ask us most often.
How does each technology actually work?
FDM melts a thermoplastic filament and extrudes it layer by layer onto a build platform. It is the most accessible and widely used form of 3D printing, capable of producing large, durable parts at a low cost per gram, using filament sourced from suppliers like OzFDM.
SLA uses a UV laser, or a UV light source in MSLA and DLP variants, to cure liquid photopolymer resin layer by layer. Because both the layer thickness and the XY resolution can be much finer than FDM, SLA produces parts with smoother surfaces and sharper detail. The trade off is a narrower material list and smaller build volumes.
When should I choose FDM?
FDM is the workhorse of advanced manufacturing. Reach for it when you need large parts, structural strength, a wide range of engineering materials, or a low per part cost on a production run. Our largest machines print up to one metre in any direction, and no other technology matches that envelope at reasonable cost.
Parts with any dimension over 150 to 200 mm
Structural or load bearing components
Engineering thermoplastics: nylon, CF, PC, ASA
Production runs where cost per part matters
Parts that will be sanded, painted or airbrushed
When should I choose SLA?
SLA wins on detail and surface finish. If your project requires fine features (text smaller than 2mm, complex undercuts, smooth organic surfaces, or medical grade accuracy), SLA is the tool for the job. Typical resin layer heights are 0.025 to 0.05mm, against FDM's practical minimum of around 0.1mm. The trade off is that resin parts are generally more brittle than FDM thermoplastics, and build volumes are smaller.
Fine detail work: miniatures, jewellery, dental, medical
Smooth surfaces with minimal post processing
Display models where aesthetics are the priority
Master patterns for moulding or casting
Parts under roughly 200mm in all dimensions
Can I combine the two on one project?
Often, yes. For our industrial scale models we routinely blend the two technologies. FDM handles the large structural body (an oil rig deck, a processing facility, a mine site layout), while SLA produces the fine detail: valve assemblies, pipe connections, small signage and intricate mechanical components.
That hybrid approach is only practical when both technologies are managed under one roof with a shared workflow. It is one of the reasons our scale models achieve a level of realism that single technology shops cannot match.
Quick tip
If you are still not sure which technology fits, ask three questions: how big is the part, how important is surface finish versus material performance, and what is your budget per part. Large and functional points to FDM, small and detailed points to SLA.
How do I decide for my project?
Run through the three questions in the tip above and you will usually have an answer. If it is still unclear, send us the CAD file and we will assess your application and timeline, then recommend the approach or combination of approaches that gives you the best outcome.