If a printed prototype has already passed fit and functional testing, what are the first design changes you would make before sending it for injection molding?
Specifically, how early do you account for things like draft angles, uniform wall thickness, ribs, bosses, and parting lines? Have you ever had a prototype that worked perfectly when printed but required major geometry changes once injection molding was considered?
Product development is a continuous, overlapping, and interdisciplinary process involving design, engineering, and manufacturing. While it is useful to break the process into stages for basic understanding, in practice, these stages rarely have clear starts and stops.
We begin considering basic DFMA as early as proof of concept verification. At that point, we are already thinking about the likely manufacturing process and possible production materials. Those decisions also influence how we prototype—for example, choosing a prototype material and process that can approximate the relevant properties of the intended production part.
More detailed manufacturing considerations typically begin around Engineering Validation Testing (EVT), with much deeper DFMA work happening as we move toward Design Validation Testing (DVT). Draft angles, wall thickness, ribs, bosses, parting lines, undercuts, tool access, ejection, shrinkage, and similar requirements progressively become part of the geometry rather than being treated as changes to make at the end.
The underlying principle is simple: how the product will eventually be manufactured should be considered from the beginning, with the level of detail and priority increasing as the design matures.
One of the most common problems we see is teams perfecting a proof of concept or printed prototype first and only then considering production. The prototype may fit and function perfectly, but the geometry can still be extremely expensive—or sometimes impractical—to injection mold without significant redesign.
Note - I also went through your profile; it’s good to see a company in decorative and HMI/interface products for industrial, automotive and electronics applications using Formlabs and exploring its applications in prototyping.