DFM review
Provenance: maintained in earthtojake/text-to-cad. Use the installed local skill files as the runtime source of truth.
Produce a process-specific DFM review of the supplied design. This is a guided review skill, not an automatic feature-recognition or manufacturing certification engine. Report unavailable checks explicitly.
Pick the process, then read its reference. One of them, or more than one when the user is comparing:
| Process | Reference | Measurement |
|---|---|---|
| Sheet metal | references/sheet-metal.md | none; use CAD inspection or supplied dimensions |
| CNC machining / turning | references/cnc.md | none; use CAD inspection or supplied dimensions |
| Injection molding | references/injection-molding.md | scripts/mold_tool.py measures draft, undercuts and projected area |
Each reference carries that process's review checklist, its two fallback sources, and a worked reasoning example. The rules below apply to all three.
For additive manufacturing, use $dfam-check, which measures mesh
printability per process.
Evidence first
Prefer the user's actual supplier/tooling specification over general guidance. Record conflicting specifications rather than silently choosing.
Identify the reviewed file and revision, units, and bodies. Prefer exact STEP/B-rep measurements for radii and analytic faces. If only a mesh is available, record its resolution and approximation limits. A screenshot supports a suspected issue, not a measured pass/fail. Source-code parameters describe design intent; verify that they match the artifact being reviewed before treating them as evidence.
When $cad is available, use its documented inspection workflow for geometry facts. If it cannot measure a required feature, use supplied dimensions with provenance or mark the check unverified; do not invent commands or measurements. Never infer alloy, resin, strength, or stock thickness from a rendering material or color.
Rule selection
- Use the selected shop's specification for the actual material and process.
- Where none is supplied, use the two references named in the process file as a starting point. Neither establishes the capabilities of an arbitrary machine, tool or fixture.
- Record URL/document version, access date, section, units, and the applicable material/tooling conditions with every adopted limit. If the source cannot be checked, report the missing rule rather than manufacture a default.
Do not turn a supplier's recommendation into a physical law or its machine capacity into a universal process limit. Preserve uncertainty and distinguish measured geometry from planned manufacturing decisions.
Report and redesign
Return a concise Markdown report in chat or the user's requested report file:
- Scope: artifact/revision, parts, process, material, units, tooling assumptions.
- Findings: part/feature, evidence and measurement method, applicable rule and source, result, and a concrete suggested change.
- Coverage: checks performed and checks not measured, including what is needed to resolve them. No findings is not a blanket manufacturability approval.
| Part / feature | Evidence | Applicable rule | Result | Suggested action |
|---|---|---|---|---|
| Named feature + location | Measured value, units, artifact revision, method | Source section + threshold + conditions | pass / fail / review / unverified | Specific change or missing evidence |
Use pass only for a measured feature satisfying a cited applicable limit; fail for a measured violation; review for a qualitative risk; and unverified when evidence or process context is missing. Include units, measurement uncertainty, and source section/table in numerical comparisons. If uncertainty straddles the threshold, leave the check unverified. Keep cost suggestions separate from manufacturing constraints. If only a render is provided, list visible concerns as review items and request geometry or dimensions for the required measurements. Never fill a report with invented feature IDs or sample values.
For requested redesign, preserve the original artifact and use $cad if available to modify the source, regenerate, and recheck the new artifact. Check affected neighboring features as well as the original finding. Without editing tools, provide a specific change list. A review request alone does not request edits, uploads, ordering, or machine operation.
Geometry measurement (injection molding only)
scripts/mold_tool.py is the one measurement script here; the other two
processes have no geometry analyzer. Install requirements.txt first — only
these measurements need it.
bashpython scripts/mold_tool.py measure part.stl --pull z python scripts/mold_tool.py pulls part.stl
The tool is fact-only: it reports measurements and never emits pass/fail. Comparisons against resin, texture and tooling limits belong to the review. references/injection-molding.md documents what each fact family means and how to read it.
