Today I'm writing about how and why you might choose a certain type of 3D printing technology.
There's a lot to consider when selecting a prototyping technique. What do you hope to learn with this build? 1. Mechanism proof-of-concept 2. Fundraising 3. User testing 4. Verification testing 5. Testing assembly methods 6. RF/communications 7. Ingress testing (dunk testing) We can answer each of these questions with different prototyping methods. Prototyping methods for each unit can be different. We may build several variations for each type of test. Functional (works-like) Technologies: FDM, SLS, MJF, Urethane Casting, Machining For parts that are only functional/mechanical, or totally hidden. These really don't need to have any special appearance requirements. Typically done at early product development phase when design is far from finished. These technologies are extremely tough/durable and will work well. Appearance (looks-like) Technologies: SLA, SLS, MJF, Polyjet SLA is my go-to for appearance models. The parts are smooth as glass, and dimensionally accurate to within 0.004" One challenge is that SLA can be brittle. Be careful when handling SLA parts, especially in the wintertime. I'd probably pick SLS or MJF-Nylon if the appearance model needs toughness, but both would need to be painted to match your appearance requirements. SLS and MJF are dusty/matte and not a final surface finish. Parts will deflect more than PC-ABS though. Functional + Appearance (looks-like, works-like) Technologies: SLA, SLS, MJF, Urethane Casting, Machining, Polyjet These prototypes are always the trickiest and the most expensive. They're supposed to match the ultimate final design, while not using the final production methods. Urethane casting is popular when budgets can't justify soft-tooling. Casting can use color-matched urethane, and the surface finish will look like a molded part. I generally recommend waiting on these combined prototypes until further along in the development cycle. There's still too much unknown about the design. Sometimes we accelerate a looks-like/works-like model to bring to a tradeshow, but generally they're the most expensive type of prototype to build. There are a ton of technologies and none of them are the magic bullet for every case. Call me if you want a personalized recommendation.