# Yellow school bus — design draft

332 catalogue units in 44 part-and-colour lots. Eight studs wide; about 27.2 cm long, 6.4 cm wide, and 9.4 cm high. The complete steering-wheel assembly counts as one catalogue unit. Minifigures are not included.

The bus has four wheels, a driver on the left, eight passenger seats, a fixed four-pane entrance, and a removable roof. Four modified plates hold the roof on eight studs. The blank black tile on the front accepts the optional SCHOOL BUS paper label shown in the preview. This is not a special printed LEGO part.

## Files

- `school-bus.mpd`: the LDraw model for BrickLink Studio. The roof is a separate submodel. The model contains 13 build stages.
- `bricklink-wanted-list.xml`: shopping quantities and BrickLink colour IDs. It does not set a price or a new/used condition.
- `parts.csv`: the same inventory with LDraw and BrickLink part numbers in separate columns.
- `front-label.svg`: optional 31 × 7 mm paper label. Print at 100% size.
- `catalog-check.json`: public catalogue checks for each required part-and-colour combination. This does not confirm current seller stock or shipping prices.

## Open and review

1. Install [BrickLink Studio](https://www.bricklink.com/v3/studio/main.page).
2. Select File → Open and choose `school-bus.mpd`.
3. Inspect the model. Run Studio's collision, connectivity, colour-availability, and stability checks. Inspect the removable roof separately.
4. Resolve any issues before ordering. This draft has not been opened in Studio or assembled with physical bricks.
5. Upload `bricklink-wanted-list.xml` to [BrickLink's Wanted List upload page](https://www.bricklink.com/v2/wanted/upload.page). Review all quantities, colours, and condition choices.
6. Use Buy All to compare sellers. Check the total, shipping, and store minimums before checkout.

## Checks completed here

- The model, CSV, and XML inventories agree.
- All referenced part geometry and its dependencies resolve from the official LDraw library.
- No duplicate part placements or nominal body-envelope collisions were found.
- All 332 units form one connected graph through aligned stud/socket ports, window clips and wheel mates. Three chassis braces and the steering stand were moved onto the connection grid.
- `digital-checks.json` records the shared workbench engine report. Special shapes use simplified or partial collision envelopes and remain review items.
- A cylindrical tyre-sweep check keeps the ordinary rectangular parts clear of all four tyres. The raised floor has 1.6 mm nominal clearance above each tyre.
- The curved roof and hood slopes were checked using their actual LDraw origins and rendered geometry.
- The preview loads the exported model itself. It is not a separate illustration.

These checks do not replace Studio's connection and stability checks or a physical test build. The entrance does not open. The wheels use matched pin-hole rims and pin holders; their fit still needs a physical check.

## Sources and attribution

- Geometry: [official LDraw parts library](https://library.ldraw.org/), complete archive downloaded October 18, 2026. Part files retain their original author and CC BY 4.0 licence headers. The local library includes `CAreadme.txt` and `Readme.txt`.
- [LDraw file format](https://www.ldraw.org/article/218.html): coordinates, units, matrices, and build steps.
- [Studio import formats](https://studiohelp.bricklink.com/hc/en-us/articles/6502277722647-Import-formats): support for LDraw `.ldr` and `.mpd` files.
- [Upload a model as a Wanted List](https://studiohelp.bricklink.com/hc/en-us/articles/5705925898135-Upload-as-a-Wanted-List).
- [BrickLink rim 55981](https://www.bricklink.com/v2/catalog/catalogitem.page?P=55981): confirms compatibility with tyre 58090.
- Part and colour IDs: BrickLink's public catalogue, linked separately for every lot in `parts.csv` and `catalog-check.json`. LDraw IDs `3069b`, `3070b`, and `6141` map to BrickLink IDs `3069`, `3070`, and `4073`.
- Preview renderer: [Three.js](https://threejs.org/), MIT licence; [LDrawLoader](https://threejs.org/docs/pages/LDrawLoader.html).

This is an independent personal design, not an official LEGO set.