Picking a prototyping technique by default — because it’s what a shop offers, or what worked last time — is how founders end up with a part that looks right and fails the moment it gets tested. The technique has to match the question being asked. A part meant to test grip feel needs a different process than one meant to test whether a snap-fit survives a drop.
This is a comparison guide, not a tutorial: five techniques, what each is actually good for, what it costs, and how fast it turns around.
The Five Techniques That Cover Almost Every Prototype
| Technique | Best For | Typical Turnaround | Rough Cost per Part | Materials |
|---|---|---|---|---|
| FDM 3D Printing | Early-stage form checks, fast iteration | 1–3 days | $20–$150 | PLA, ABS, PETG |
| SLA 3D Printing | Surface finish, visual/investor samples | 2–4 days | $40–$250 | Photopolymer resins |
| SLS 3D Printing | Functional plastic parts, living hinges | 3–5 days | $60–$300 | Nylon (PA11/PA12) |
| CNC Machining | Tight tolerances, metal parts, load-bearing components | 3–7 days | $80–$500+ | Aluminum, steel, hard plastics |
| Urethane Casting | Bridging to production, small runs of near-final parts | 5–10 days | $30–$150 | Cast urethane resins |
(Figures should be checked against current shop rates before publishing — directional, not quoted pricing.)
Match the Technique to the Question, Not the Product Category
- “Does this look and feel right?” → SLA or SLS. Surface finish and geometry accuracy matter more than material strength here.
- “Will this survive real use?” → CNC machining in the actual production material, or SLS nylon if the final part will be injection-molded plastic. A part printed in PLA can pass a hand test and still fail once made in the real material — the plastic behaves differently under stress.
- “Can I get 50 of these to send to beta testers?” → Urethane casting. It’s the bridge between “I have one good prototype” and “I need enough units to run a real test,” without paying for injection tooling first.
- “I just need something to hold and iterate on fast.” → FDM. Cheapest, fastest, least representative of final material behavior — which is fine, because that’s not the job at this stage.
Common Mistake — Designing for the Wrong Process
A part optimized for 3D printing (thin walls, internal lattices, printer-specific tolerances) often can’t be manufactured the same way once it moves to injection molding or CNC production. Undercuts that a printer handles without issue become a mold-release problem at production scale. If the plan is to prototype now and manufacture later, the prototyping technique should be chosen with the production method already in mind — not picked in isolation.
From Prototype to Small Batch
Once a design has passed functional testing, moving to small batch production doesn’t require starting over with a new vendor or new files. PrototyperLab’s small batch production starts at 20 units and uses the same CAD files and engineering team that built the prototype, at the same $25/hr transparent rate — no factory minimums, no re-quoting from scratch.
FAQ
Which technique is fastest? FDM, typically 1–3 days for a simple part. Speed comes at the cost of material realism — it’s the right choice for early form checks, not final validation.
What’s the most common mistake in choosing a technique? Picking based on what’s cheapest or fastest rather than what the prototype needs to prove. A $30 FDM part that gives a false pass on a mechanical test costs more in the long run than a $200 CNC part that gives an honest answer.
Can one product need more than one technique? Usually, yes. Most real products combine a housing (SLS or CNC), a soft-touch component (silicone), and sometimes electronics (parallel PCB development) — tested together, not in isolation, since integration problems only show up once the systems are combined.
How does this connect to small batch manufacturing? Once a prototype passes functional testing, it moves into small batch production starting at 20 units, using the same design files and engineering team — no new vendor search required.
Not sure which technique fits your project? Get a free itemized quote and PrototyperLab’s engineering team will recommend the right process before a single part is built.