FDM Versus SLA for Startup Prototypes

Choose FDM when you need fast, practical parts for fit checks, enclosures, brackets, fixtures, and repeated hardware iteration. Choose SLA when very fine detail, small features, or a smoother presentation surface matters more than the typical convenience and toughness of an FDM prototype.

AIURION currently offers FDM in PLA and PETG. It does not offer SLA, so some prototype requests should go to a resin-printing provider instead.

FDM and SLA compared

Requirement	FDM	SLA
Typical startup use	Enclosures, brackets, fixtures, assembly and fit checks	Detailed presentation models, miniatures, fine text, smooth small features
Surface character	Visible layer lines	Generally smoother and finer-detail surface
Material handling	Filament-based; practical for many workshop prototypes	Liquid resin requires washing, curing, and process-specific handling
Iteration	Strong for quick mechanical revisions	Strong when visual or small-feature fidelity drives the revision
Part behavior	Depends on polymer, geometry, and layer orientation	Depends on resin formulation and cure; some resins can be less forgiving in handling
AIURION availability	PLA and PETG available	Not currently offered

Choose FDM for mechanical learning

FDM is often the better startup default when the prototype exists to answer questions such as:

• Does the PCB fit?
• Are the mounting holes and bosses in the right place?
• Can the enclosure assemble without interference?
• Does the bracket clear the frame?
• Is the cable route practical?
• Can the team test several geometry revisions quickly?

PLA is useful for many visual and dimensional prototypes. PETG can be a better fit when the prototype needs more handling tolerance or a different balance of stiffness and durability. Neither material should be treated as universally production-ready.

Choose SLA for fine detail and presentation finish

SLA is often the better route when the most important requirement is tiny detail, crisp text, smooth small surfaces, or a presentation model whose visible layer texture would undermine the demonstration.

Examples include:

• miniature product models;
• very small text or embossed features;
• detailed scientific or anatomical geometry;
• jewelry-like visual prototypes;
• small parts where FDM nozzle width limits the feature definition.

Resin choice still matters. A visually excellent SLA print is not automatically appropriate for load, heat, prolonged exposure, or repeated mechanical use.

Do not choose based on appearance alone

The better-looking process is not always the better prototype process. A smooth model can be useless if it does not represent the assembly interfaces accurately enough for the intended test. Conversely, a mechanically useful FDM part may be the wrong object to put in front of an investor if the conversation depends on fine visual detail.

Start with the decision the prototype must support, then choose the process.

A startup decision checklist

Choose FDM when most of these are true:

• the part is an enclosure, bracket, fixture, housing, or fit-check model;
• the important features are large enough for the available FDM setup;
• visible layers are acceptable;
• PLA or PETG fits the test environment;
• turnaround and repeated iteration matter.

Choose an SLA provider when most of these are true:

• very fine surface detail drives the value of the model;
• the part is small and feature-dense;
• presentation finish matters more than workshop handling;
• the required resin and post-processing are understood;
• the deadline allows the complete print, wash, and cure workflow.

Where AIURION fits

AIURION’s rapid-prototyping service in San Francisco is built around human-reviewed FDM work in PLA and PETG. It is a strong fit for hardware teams that need quick-turn enclosures, fixtures, fit checks, brackets, and small batches.

If the file needs SLA-level detail or a resin-specific property, AIURION is not currently the right production provider. Identifying that before accepting the order is part of the service.

Bottom line

FDM is the practical default for many startup hardware iterations. SLA is the better choice when fine detail or smooth small-scale presentation quality is the primary requirement. Pick the process that answers the next engineering or communication question—not the process with the more impressive sample photo.