3d-print

name	3d-print
version	0.2.0
description	Search-first 3D printing workflow — finds real specs before modeling, generates manifold-safe models for Bambu Studio / PrusaSlicer / Cura / Fusion 360
triggers	["3D print","create STL","generate model for printing","design for 3D printing","make a 3D printable","print this part","3d printable","slicer","FDM","print bracket","print mount","print enclosure"]

3D Print Skill

Purpose

Generate physically accurate, print-ready 3D models without fabricating dimensions. Always search for real specs first. Never guess measurements.

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Workflow

Step 1 — Search for real specs

First, try the local search script:

python3 scripts/search_specs.py "Canon EF 40mm f2.8 lens outer diameter"

If the script returns no concrete millimeter values (status: no_instant_answer or vague text), do NOT stop. Use your own search_web tool to query the product's official datasheet, spec page, or Wikipedia. Extract the three key numbers: outer dimension, inner dimension, height. Only proceed to Step 2 once you have real numbers with a source you can cite.

All results are cached to specs_cache.json. On a cache hit, read the cached result and extract dimensions directly — no re-search needed.

Step 2 — Decide: preset or custom script

Check if the request matches a preset:

python3 scripts/generate_model.py --preset cube     # 20mm calibration cube
python3 scripts/generate_model.py --preset tube     # hollow cylinder
python3 scripts/generate_model.py --preset bracket  # box with through-hole

If the request does NOT match a preset (e.g. "lens cap with snap-fit tabs", "hook with chamfer", "enclosure with lip", "multi-part assembly"), write a custom Python script on the fly. Use the pattern:

import sys
sys.path.insert(0, "scripts")
import manifold3d as m3d
from generate_model import export_3mf, export_stl
from pathlib import Path

# --- build geometry using manifold3d primitives ---
# See references/manifold-examples.md for API reference:
# extrusion, revolve, hull, chamfer, loft, snap-fit tabs, threads

body = m3d.Manifold.cylinder(height=8.0, radius_low=34.0, circular_segments=64)
inner = m3d.Manifold.cylinder(height=8.2, radius_low=33.0, circular_segments=64)
result = body - inner.translate([0, 0, -0.1])

# --- export ---
out = Path("output")
export_3mf(result, out / "lens_cap.3mf", name="lens_cap")
export_stl(result, out / "lens_cap.stl")

Save the script as output/<name>_build.py, run it, then proceed to Step 3. The export_3mf and export_stl functions from generate_model.py handle all file-format details — just call them with the final Manifold object.

Step 3 — Validate the mesh

python3 scripts/validate_mesh.py output/lens_cap.stl

If validation fails, do NOT just run --fix and move on. Read the specific failing checks, trace them back to the geometry construction, and fix the root cause in the build script. Common fixes:

• watertight: FAIL → a boolean operation left an open edge; add a small Z-offset (e.g. translate([0, 0, -0.1])) on the subtracted body so it protrudes past the face
• positive_volume: FAIL → normals are inverted; the outer shell may be smaller than the inner — check radii
• no_degenerate_faces: FAIL → a zero-thickness wall from a tight boolean; add at least 0.4mm clearance between faces

After fixing, re-run the build script and re-validate. Repeat until all critical checks pass.

Step 4 — Slice

Import .3mf into Bambu Studio / PrusaSlicer / Cura. Expected: 0 non-manifold errors, 0 open edges.

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Spec Extraction from Cache

When specs_cache.json already contains an entry for the target part, load and extract dimensions directly instead of re-running search:

import json
cache = json.load(open("specs_cache.json"))
# find the entry whose query matches your part
# read result["answer"] or result["abstract"]
# parse out numeric values (mm) using your own reasoning
# map to: outer_diameter, inner_diameter, height, wall_thickness, etc.

Use your reasoning to map prose descriptions ("67.5mm filter thread") to the correct variable in the build script. Do not ask the user to do this mapping manually.

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Reference Files

File	Contents
references/formats.md	STL vs 3MF vs STEP — when to use each
references/tolerances.md	FDM accuracy, shrinkage, fit clearances
references/design-rules.md	Manifold rules, wall thickness, overhang limits
references/manifold-examples.md	manifold3d API: extrusion, revolve, hull, chamfer, snap-fit, threads

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Key Constraints

• No fabricated dimensions — search first, use real numbers with a cited source
• manifold3d for all geometry — guarantees no non-manifold edges
• Custom script when no preset fits — generate_model.py is a reference, not a limit
• 3MF primary output — ISO/IEC 25422:2025, manifold-safe, Bambu/Prusa/Cura compatible
• Fix root cause on validation failure — do not rely on --fix alone

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Common Errors

Error	Cause	Fix
"244 non-manifold edges" in Bambu	numpy-stl or bad boolean	Regenerate with manifold3d
Hole too tight	FDM shrinks holes	Add +0.1–0.2mm radius compensation (tolerances.md)
Part snaps during press fit	No interference margin	0.1–0.3mm interference (tolerances.md)
Overhangs fail	>45° without supports	Redesign or add supports in slicer
watertight: FAIL	Subtracted body flush with face	Add Z-offset of 0.1mm on subtracted body
search_specs.py returns empty	DuckDuckGo Instant Answer has no entry	Use search_web tool on manufacturer datasheet

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Install

ln -sf /path/to/3d-print-skill ~/.claude/skills/3d-print

Dependencies

pip install manifold3d trimesh numpy requests