Any decision to use 3D printing, machining, or injection molding should begin with the answer to one key question– “How will the part be used?”
Are you looking for a concept part or a final production part?
Are you testing a material?
Are you checking form-fit-function or tolerances?
These are just a few examples of questions to answer.
Also consider the simplicity or complexity of a design. Part complexity narrows a choice, often in favor of additive manufacturing. But simple parts can be deceiving, depending on the features needed.
Knowledge of the major 3D printing technologies will influence the decision. Each technology offers pros and cons for a design.
On the other hand, injection molding offers a predictable and scalable process for both rapid prototyping and production project needs. Its ability to produce parts from multiple materials with a high degree of consistency and tight tolerance makes it a proven approach to manufacture parts.
With injection molding, consider a number of best practices including resin selection, wall thickness, draft, runners and gates, ribs, bosses, corners and transitions. Beyond best practices, injection molding offers several key features that can transform a design including overmolding, insert molding, and undercuts. Tolerances are ± 0.005 in. and can reach
± 0.001 in. with tooling. Consider these key features as a reason why injection molding should be applied to your project.