Prototype budgets disappear fastest when every round is built “as close to production as possible”. The better approach: decide what question each prototype must answer, then pick the fastest, cheapest method that answers it. A looks-like model for an investor meeting and a drop-test sample for certification need very different processes.
Match the method to the question
| Question | Best methods | Why |
|---|---|---|
| Does it look and feel right? | SLA print + paint; CNC + finishing | Smooth surfaces, accurate cosmetic appearance |
| Does it fit with other parts? | SLA, SLS/MJF, CNC | Dimensional accuracy, quick iterations |
| Does it work under load / heat? | CNC in production material; SLS/MJF nylon | Real material properties |
| Do users like it? (10–50 units) | Vacuum casting, SLS/MJF | Molded look in small quantities |
| Will it pass tests and certification? | Rapid (aluminum) tooling in production resin; production-like PCBA | Same material and process as production |
| Does the electronics work? | Quick-turn PCBA, dev boards early on | Validate circuits and firmware in parallel with mechanics |
Methods at a glance
| Method | Typical quantity | Strengths | Limits |
|---|---|---|---|
| 3D printing | 1–50 | Fastest, any geometry, cheap iterations | Material properties differ from molded parts |
| CNC machining | 1–100+ | Production metals and plastics, precise | Geometry limited by tool access; cost rises with complexity |
| Vacuum casting | 10–50 per silicone mold | Molded look, colors, overmold-like soft touch | Polyurethane resins simulate, not equal, production plastics |
| Rapid tooling (aluminum) | Hundreds+ | Real resin, real process | Tooling cost and time; less flexible to change |
| Quick-turn PCBA | 1–50 boards | Real electronics | Component availability can set the pace |
How to keep prototype rounds under control
- Write the question each round must answer, and the pass/fail criteria, before ordering.
- Change one major thing per round where possible, so results are interpretable.
- Mix methods in one build: machined structure, printed covers, quick-turn PCBA.
- Design each prototype with the production process in mind (draft, walls, standard parts) so learning transfers.
- Freeze the design before tooling — late changes are where budgets are lost.
Prototype stages lead into EVT, DVT and PVT. See our rapid prototyping capability or tell us what your next prototype must prove.