Prep a model in Blender
Check a Blender model's scale, mesh, and wall thickness, then verify the exported file.
Paste it into Claude Code, Codex, Cursor or any agent. No account needed.
View prompt
Use the Benchy skill "Prep a model in Blender". 1. Read https://benchy.world/skills/prep-a-model-in-blender/files?path=SKILL.md and follow it. If you support skills, save it as one. 2. Save https://benchy.world/skills/prep-a-model-in-blender/files?path=BENCHY.md as BENCHY.md at the root of my project, and keep it current as we work. 3. Then start on this: Use this skill to prepare planter.blend for printing on a 0.4 mm nozzle. Keep my original and tell me what you changed.
What you’ll need
Use all of these apps
- Blender
Blender 4.2 or later
- A model Blender can import
Suggested: BLEND · GLB · STL · OBJ
Agent skill · Version 0.1.1 · MIT license
What you can work toward
- Set millimetre units and catch models exported 1000× or 25.4× off
- Apply transforms and close non-manifold geometry, reporting counts before and after
- Review wall thickness against the planned print settings
- Export with an available exporter and re-import to confirm dimensions
Skill files
The instructions your agent follows. Review them first: tools, connections and execution depend on your setup.
--- name: prep-a-model-in-blender description: >- Prepare a model in Blender for 3D printing: real-world scale in millimetres, applied transforms, a closed and consistently oriented mesh, wall thickness suited to the intended print process, and an export verified by re-importing it. Use after a model exists (made, downloaded or scanned) and before it goes to a slicer. title: Prep a model in Blender date: 2026-09-26 author: Benchy tags: [3d-printing, blender, mesh, export, skill] license: MIT metadata: version: "0.1.1" schemaVersion: 2 surface: "Blender 4.2+ · no account needed" --- # Prep a model in Blender Check the model's scale, mesh, and wall thickness, then export and verify a copy. Slicer preview and print-process checks follow separately. ## Requirements Blender 4.2 or later, run either by the user or by the agent through Blender's command line (`blender --background --python script.py`) or an authorised Blender connection. If none is available, say so and stop; do not describe checks you could not run. Work on a copy. Keep the user's original file untouched and save the prepared model under a new name. ## Steps 1. **Set units.** Scene → Units: Metric, Unit Scale 1.0, Length in millimetres. A model imported from another tool is often 1000× too small or 25.4× off (inches); compare its bounding box with the dimensions in the plan, and rescale only with the user's confirmation. 2. **Apply transforms.** Select the printable objects and apply rotation and scale (Object → Apply → Rotation & Scale). Recheck the dimensions afterward. 3. **Make one closed mesh per part.** - Merge unintended duplicate vertices using a distance small enough to preserve designed gaps and details. - Recalculate normals outside. - Find non-manifold geometry (Select → All by Trait → Non Manifold) and fix holes, loose edges and internal faces. - Where separate shells overlap, join them with a Boolean union, or keep them as separate parts on purpose. - The 3D-Print Toolbox extension reports these checks in one panel. Use it where installed, and report its numbers. 4. **Check thickness.** Compare walls with the intended extrusion width, perimeter count, material, and load. Two nozzle widths is a starting check, not a universal minimum. List thin areas rather than changing them without the user's approval; confirm their toolpaths in the slicer. 5. **Orient for the plate.** Put the face named in the plan's print orientation on the XY plane at Z = 0. The slicer can re-orient, but the file should arrive in the intended position. 6. **Export.** - Use an exporter available in the installed Blender version. Use 3MF only when a compatible exporter is installed and the receiving tool supports it. - STL is unitless: record the intended units and export settings beside it. - Export selected objects only, with modifiers applied. 7. **Verify the export.** Re-import the exported file into an empty scene and measure its bounding box against the plan. Report the three dimensions. An export that was not re-imported is unverified. ## Report Return the prepared `.blend`, the print file, and a short list: scale and bounding box, non-manifold count before and after, thin areas found, the orientation used, and anything left for the user to decide. Report only the checks you ran. Keep the original, prepared `.blend`, print file, and check results together. ## What this skill does not do It does not redesign the model, add supports (the slicer does that), or declare a model printable. A clean mesh is necessary for a good print, not sufficient.