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BUILT BY AUTONOMOUS SYSTEMS · WORK IN PROGRESS
# Catalog item format
Every file in `catalog/` is a JSON list of items in this shape. Unknown values are `null`, never guessed.
```json
{
"id": "cubemars-ak70-10", // vendor-model, lowercase, dashes
"category": "leg_actuator", // see the categories below
"vendor": "CubeMars",
"model": "AK70-10",
"price_usd": 459.0, // one unit, before shipping and tax; null if no public price
"price_note": "official store, single unit",
"price_checked": "2026-10-25",
"buy": [{"seller": "CubeMars store", "url": "https://...", "in_stock": true, "ships_from": "CN"}],
"specs": { // units are in the key names
"mass_g": 521, "diameter_mm": 104, "length_mm": 53,
"peak_torque_nm": 24.8, "rated_torque_nm": 8.3,
"no_load_speed_rpm": 310, "rated_speed_rpm": null,
"gear_ratio": 10, "voltage_nominal_v": 24, "voltage_range_v": [18, 52],
"peak_current_a": null, "kt_nm_per_a": null,
"interface": "CAN", "encoder": "14-bit single, dual for output?",
"hollow_shaft_mm": null, "ip_rating": null
},
"cad": {"step_url": "https://...", "available": true},
"sources": ["https://datasheet...", "https://product page..."],
"confidence": "datasheet", // datasheet | product page | seller listing | estimate
"notes": "Anything that matters for a wheel-legged robot."
}
```
Categories: `leg_actuator`, `wheel_motor`, `motor_driver`, `wheel`, `tire`, `battery`, `bms`, `charger`, `dcdc`, `power_distribution`, `estop`, `can_adapter`, `imu`, `compute`, `sensor`, `display`, `light`, `wiring`, `fastener`, `bearing`, `cf_tube`, `cf_plate`, `sheet_material`, `filament`, `fab_service`, `turret`.
`"preferred": true` marks the default choice the designer starts from. The BOM groups items into **Sensors & compute** (`compute`, `sensor`) and **Chassis & actuators** (everything else), each with its own subtotal.
## Pictures and alternates
Three more files sit beside the catalogue (they are objects, not item lists, and are not in `index.json`):
- **`images.json`** : a picture of every part on a parts list, by catalogue key (or printed part name): `{source_url, image_url, fetched, path, kind}`. `kind` is `mcmaster` or `vendor` (a product photo, kept in `references/vendor/thumbs/`, gitignored: not ours to redistribute) or `render` (our CAD, `exports/thumbs/`). McMaster entries also keep the product page's delivery line on the day it was read (`availability`). Written by `tools/part_images.py`.
- **`alternates.json`** : other places to buy each bought part, by catalogue key: a list of `{supplier, part_number, url, price, price_usd_each, pack_qty, stock, drop_in, changes, checked}`. `drop_in` is true only when the alternate fits the same seat and does the same job with no CAD change; otherwise `changes` says what would change. `price` and `stock` are as the page showed them on `checked`.
- **`sourcing.json`** : what a parts list's plain-text line means (`names`: text or part name -> key, or a list of keys when one line buys several products), lines that are part of another (`skip`), where a vendor part's picture is taken from when its buy link is not the right page (`image_pages`, `image_urls`), parts that are hard to buy (`risk`: `{level: high | medium | cost | fit | missing | check, note, checked}`: hard to buy, single source, a much cheaper option, a part that does not fit the design as drawn, parts the list leaves out, a rating to check; shown on the progress page), and the bought parts no catalogue file has yet (`parts`, in the item shape above plus `key`).
`cad/bom_media.py` `enrich(lines)` adds `thumb` and `alternates` to parts-list lines from these files.
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