Injection molding punishes bad design decisions — once tooling is cut, changes are expensive. I design plastic parts mold-ready from the start, or review and fix an existing design before it goes to the toolmaker.
Overview
Injection molding is unforgiving of design mistakes in a way FDM or CNC prototyping isn't. Draft angles have to be right or the part won't eject from the mold. Wall thickness has to be uniform or you get sink marks, warping, and differential cooling. Gate location affects flow, weld lines, and cosmetic quality. Parting line placement affects both appearance and how complex — and expensive — the tool itself needs to be.
These are decisions that are cheap to get right in CAD and expensive to fix after steel has been cut. This service covers both directions: designing a new plastic part mold-ready from the very first feature, or reviewing an existing design and fixing the specific issues before it goes to a toolmaker.
How It Works
Define function and load requirements, then select a resin that fits both mechanically and for moldability.
Model the part with draft angles, uniform wall thickness, and rib/boss geometry built in from the first feature, not retrofitted.
Recommend gate location and parting line placement based on flow behavior, cosmetics, and tool complexity.
Deliver a design your moldmaker can quote and tool directly, with no clarification rounds needed.
What You Get
Parametric design with draft angles, wall thickness, and rib geometry all built to injection-molding rules.
Resin selection based on mechanical requirements, cost target, and moldability.
Marked-up recommendations for where the tool should gate and split.
Dimensioned 2D drawings and notes ready to send straight to a moldmaker for quoting.
FAQ
A review-only pass is common and usually enough — the goal is flagging and fixing specific mold-breaking issues like undercuts, thin walls, or missing draft rather than redesigning the whole part from scratch.
This is a deep-dive on injection molding specifically — gate placement, parting lines, weld line prediction, and resin-specific shrinkage — which goes further than a general manufacturability audit across processes.
A specific material recommendation, with the reasoning — mechanical requirements, cost target, and how it behaves in the mold, including shrinkage, flow length, and cosmetic finish.
Yes — snap-fit and living-hinge geometry has its own design rules distinct from general injection molding, and both are commonly needed for enclosures and consumer products.
It depends on part complexity and whether it's a design-from-scratch or a review-only pass on an existing model. You'll get a fixed quote upfront — and catching a mold-breaking issue at the design stage is far cheaper than re-cutting steel tooling after the fact.