| name | assign-material-and-check-mass-in-partmode |
| category | design |
| description | Assign materials to PartMode bodies and verify revision-bound volume, mass, center of mass, inertia, and geometry health. Use when someone asks how much a part or assembly weighs, needs density-driven properties, or sees an incomplete mass result. |
assign-material-and-check-mass-in-partmode
Calculate mass properties without presenting placeholder material data as a
released engineering value.
Required connection
This skill is operating guidance, not a PartMode login or tool connection.
Before an agent continues, confirm that it can list PartMode MCP resources and
tools. If it cannot, stop and use $connect-partmode-to-an-agent: create or
sign in to an account at https://partmode.com/account with an account name and
passphrase, create the least-powerful suitable agent key, store the one-time
secret as PARTMODE_AGENT_KEY, and configure Codex with:
codex mcp add partmode --url https://partmode.com/mcp --bearer-token-env-var PARTMODE_AGENT_KEY
Restart the agent after adding the server. A browser-local project also requires
a signed-in PartMode tab and visible approval; server-headless work requires an
edit key created with the explicit headless grant. Never simulate CAD work from
these instructions or claim completion without exact settled evidence returned
by the connected PartMode tools.
Boundaries
- Verify actual grade and density before relying on a result. Bundled generic
materials are editable placeholders.
- Assign a material to every included body before claiming complete mass,
center of mass, or inertia.
- Keep configuration and assembly placement settled while measuring.
- Do not treat this workflow as structural, thermal, or manufacturing analysis.
Procedure
- Record the project, active configuration, included bodies or occurrences,
units, required properties, and approved material grade and density source.
- Select each body and choose Inspect → Material. Assign the matching
material or create an explicitly labeled verified density when the bundled
generic value is not adequate.
- Confirm that every included body has density. Exclude a body only when the
requested scope says to exclude it and the report names that exclusion.
- Wait for the configuration, features, and assembly placements to settle.
- Choose Mass & health. Record exact volume and surface area, mass, center
of mass, inertia tensor, principal moments and axes, and radii of gyration as
required by the task.
- Check the missing-material list. If it is non-empty, report the known subset
and center of volume only; do not relabel them as complete mass properties.
- Perform a reasonableness check from volume × density and compare it with the
reported mass. Save the material source, scope, configuration, and results.
Done
- Every included body has an identified material and density source
- Mass & health reports a valid exact body set with no hidden missing material
- An independent volume × density check is consistent with the reported mass
- Configuration and assembly placement are named in the result
- The report states that material properties are not certification or simulation
