# Generic Rotational Part Reference

## When to read this file

Read this reference when the request matches these triggers:

- `rotational part`
- `turned part`

## Object boundary

Use this reference to improve first-pass CAD modeling structure. It is not a validator, factory, or engineering certification. Do not model adjacent assemblies unless the user explicitly requests them.

## Recognition

This node represents `mechanical_part.rotating_part.generic_rotational_part` in the generated taxonomy. It was mined from 2 source models.

## Core invariants

- Identify the dominant base body before adding secondary features.
- Keep repeated holes, slots, bosses, and cuts parameterized.
- Preserve datum relationships over decorative symmetry.

## Common variants

- Keep variants driven by the user prompt and source evidence.
- Prefer adding a child variant skill when one branch becomes too specific.
- Do not collapse all examples into one fixed template.

## Required parameter roles

- `circular_edges`
- `cylindrical_faces`
- `main_axis`

## Feature roles

- `circular_edges`
- `cylindrical_faces`
- `main_axis`

## Operation / construction sequence

1. Build the primary base solid first.
2. Add major bosses or protrusions second.
3. Apply subtractive cuts, holes, pockets, and slots after the base is valid.
4. Create repeated features through patterns rather than independent ad hoc geometry.
5. Apply fillets and chamfers last.

## Common failures to prevent

- Unnamed magic dimensions hidden inside geometry calls.
- Decorative features with no functional role.
- Fillets or chamfers applied before major cuts.
- Claiming engineering performance or standard compliance from reference guidance alone.

## Validation targets

- The generated model contains the core invariants above.
- Major feature roles are visible or represented by named parameters.
- Repeated features have consistent count, spacing, and datum relationship.
- The output is a valid solid or explicitly requested assembly.

## Exclusions

- `box-like housing`

## Source evidence summary

- Source sample count: 2
- Sample ids: 000924, 001075
- Operation evidence: Extrusion: 2, HoleWzd: 2, LPattern: 2, Cut: 1, Chamfer: 1
- Taxonomy confidence: 0.74