01
Requirement authority
Reconcile the controlled model, drawing, CTQs, cosmetic zones, assembly interfaces and any conflict hierarchy before geometry changes are proposed.
Evidence route
Released revision, requirement register and open-conflict log
Injection-moulding DFM
Wall thickness and moulded-part DFM: control the complete flow, cooling and ejection problem.
Wall sections, transitions, ribs, bosses, radii, draft, gates and ejector features act together. PartVerity turns generic DFM guidance into a part-specific issue log tied to the selected resin, tool concept, measurable requirements and named engineering decisions.
Decision premise
DFM question: which geometry, resin and tool assumptions must be closed before steel is authorised?
Engineering control
Six DFM controls before tool release
Rule-of-thumb values are screening inputs—not universal capability promises. The chosen moulding route and released part requirements remain controlling.
02
Wall and transition map
Review thick masses, abrupt transitions, ribs, bosses and intersections for fill, cooling, sink, void and differential-shrinkage risk.
Evidence route
Annotated wall map, risk rationale and approved disposition
03
Resin-linked behaviour
Connect the exact resin grade, fillers, shrinkage, moisture and processing constraints to the geometry instead of treating all polymers alike.
Evidence route
Controlled resin identity and material-specific DFM notes
04
Gate and flow concept
Evaluate likely gate location, weld/knit lines, venting, flow length and pressure-sensitive features against function and appearance.
Evidence route
Tool concept, flow-risk record and agreed cosmetic boundary
05
Draft and ejection
Confirm draw direction, shut-offs, texture allowance, undercuts, ejector access and acceptable witness locations before tooling detail proceeds.
Evidence route
Draft/ejection map and approved visible-mark zones
06
Measurable closure
Turn each accepted exception or geometry change into a revision-controlled requirement that can be checked on trial parts.
Evidence route
Closed DFM log, updated files and T0/T1 verification list
Decision matrix
Geometry condition to DFM decision
The matrix frames review questions. Numeric values are confirmed against resin, tool, supplier and part function.
| Geometry condition | Control response | Evidence focus |
|---|---|---|
| Abrupt thick-to-thin transition | Blend, core, relocate or accept with explicit risk | Wall map and trial appearance/dimensions |
| Boss on cosmetic wall | Review support, mass and opposite-face witness | Sink criterion and T1 visual evidence |
| Deep textured surface | Draft, draw direction and ejection review | Texture/draft definition and trial status |
| Functional feature near gate | Flow, stress and weld-line risk review | Gate concept and functional test link |
| Tight interface across variable walls | Datum, shrink and measurement-state planning | Feature-specific trial measurements |
Claim boundaries
DFM shortcuts that do not release tooling
A generic wall-thickness range does not approve a specific geometry.
A clean flow simulation image does not prove production capability.
Toolmaker acceptance does not replace customer engineering disposition.
Changing resin after DFM can invalidate shrinkage and processing assumptions.
Technical context
Use guidance to frame the review—not to replace project evidence.
External context for wall thickness, draft, ribs, bosses, gates, ejection and material interaction. Project values remain resin-, tool- and supplier-specific.
Protolabs injection-moulding guide