Rapid prototyping gets used as a catch-all for any process that turns a CAD file into a physical medical device part quickly, but SLA, SLS, metal additive manufacturing and CNC machining answer different questions. Picking one before deciding what the prototype needs to prove is how a design cycle gets spent on the wrong part.

What "rapid" actually buys you

The speed in rapid prototyping comes from skipping tooling, not from skipping decisions. SLA and SLS plastic 3D printing support fast iteration from CAD to a physical part because there is no mold or fixture to build first — the trade-off is that the part is evaluated in resin or nylon, not the final material. Metal 3D printing (DMLS or SLM) keeps that tooling-free speed while building in titanium or cobalt-chrome, which matters when the geometry itself — a lattice, a porous structure, an internal passage — is the thing under evaluation. CNC machining is not usually described as "rapid," but for a part where final alloy, a controlled mating feature or a production-relevant surface decides the outcome, it is often the more direct route to a prototype that actually answers the question.

Match the process to what the prototype needs to prove

Every prototyping request is really answering one of a few questions. A form or fit study — does this geometry clear the mating component, does the ergonomics work — is well served by SLA's detail and surface finish. A functional handling check — a snap fit, an interlocking assembly, a part that needs to survive being handled on a bench — points to SLS nylon. Complex alloy geometry that conventional machining cannot reach economically, like a porous or lattice implant concept, is a DMLS or SLM decision. Once the question becomes final material behavior, a specified tolerance or a production-relevant surface, printing has usually answered what it can, and CNC machining is the more direct route. Plastic printing itself splits the same way — the SLA vs SLS decision comes down to whether appearance and detail or functional handling matters more for that specific build.

Prototyping is one stage, not the whole program

A rapid prototype earns its cost by settling a specific question fast — it does not need to anticipate every downstream requirement. Lab Ready's medical device manufacturing workflow carries the same part through printing, machining, finishing and fit checks as the questions change from "does this fit" to "is this the production-representative part," so a design does not have to restart with a new supplier each time the requirement changes.

Send the CAD file and note what the current build needs to prove — geometry, function, material behavior or a production-relevant surface — through the RFQ checklist or directly to Lab Ready, and the process recommendation follows from that answer.