OrlaMechCAD-Nano

A multimodal mechanical CAD dataset connecting dimensioned drawings with 3D solids.

14 paired components · 370 dimension entities · 349 BRep faces · 98 rendered part views

Data representations · Structured records · Quick start · Schema

What is OrlaMechCAD-Nano?

OrlaMechCAD-Nano brings together the drawing, solid geometry, and structured records for each mechanical component. A single example can be inspected as a dimensioned engineering sheet, opened as native CAD, viewed from seven camera directions, or queried through JSON and Parquet.

Nano is the compact, 14-component edition of the OrlaMechCAD family. It gives users a complete set of paired assets for exploring the format and developing drawing-to-geometry workflows. The collection includes brackets, plates, shafts, sleeves, a hinge block, a hub, and a sprocket.

Each component links one DWG drawing, one distinct single-solid STEP part, and one drawing PDF. The package also contains decoded DXF, drawing entities and dimensions, geometric measurements, per-face surface records, and image previews.

Key features

• Paired 2D and 3D assets. Explicit relationships connect each drawing to its STEP solid and each PDF to its source drawing.
• Dimensions as structured data. Definition points, raw measurements, displayed text, scale factors, styles, and text overrides are available alongside the drawing.
• Native solid geometry. Each STEP contains one validated boundary-representation (BRep) solid, with volume, surface area, topology counts, and oriented bounds.
• Face-level geometry. All 349 faces have surface types, areas, orientations, and type-specific geometric parameters.
• Multiple views with camera metadata. Every part has an isometric view and six orthographic axis views, with stored camera and projection matrices.
• Ready to query. Five typed Parquet catalogs support selection, joins, and file loading. Drawing and part previews support visual inspection.

One component, connected representations

The slotted rib bracket, ORL-8ff18328a, pairs a dimensioned drawing with a 28-face STEP solid.

Drawing sheet	STEP solid preview

The catalogs retain the shared component identifier and explicit asset relationships. Pairing is at the component level. Drawing entities retain their drawing or block coordinate frames; solid measurements and camera metadata use the exported body's coordinate frame.

Data representations

Representation	Included in Nano	Contents
CAD drawings	14 DWG + 14 DXF	Drawing geometry, dimensions, text, layers, blocks, and layouts
Solid CAD	14 STEP	One distinct BRep solid per component; 11 to 85 faces per solid
Drawing documents	14 PDF	Rendered engineering drawing sheets
Image previews	112 PNG	14 drawing previews and 98 part views
Structured records	JSON	Drawing entities, dimensions, text, title fields, surface geometry, measurements, and view metadata
Catalogs	5 Parquet tables	Drawings, parts, documents, part measurements, and relationships

The drawing catalogs account for 8,596 CAD entities, including 370 dimension entities and 860 text entities. Counts cover the extracted drawing contents, including their blocks and layouts.

Structured records

Drawings and dimensions

Drawing records preserve entity identities, source handles, geometric attributes, layer and block references, display properties, and coordinate-frame information. Separate files expose text, dimensions, title fields, layers, and blocks.

Dimension records include:

Field	Meaning
entity_id	Stable reference to the drawing entity
dimension_type	CAD dimension type
definition_points	Points defining the dimension in its stored frame
raw_measurement	Measurement before display formatting
raw_measurement_unit	Unit associated with the raw value
display_text	Displayed dimension text
length_scale_factor	Stored linear dimension scale factor
text_override	Explicit replacement text, when present
dimstyle_id	Reference to the dimension style

Raw measurements, dimension graphics, and visible labels remain separately addressable. Interpret scale factors with the CAD dimension style and drawing units; explicit text overrides can replace calculated values.

Solids and faces

Part measurements include solid, shell, face, edge, and vertex counts; BRep validity; volume; surface area; oriented bounding-box dimensions; and surface inventories.

Surface type	Faces in Nano
Plane	170
Cylinder	146
Cone	27
Torus	6
Total	349

Each face record carries a face identifier, the geometry hash, surface type, area, orientation, and applicable surface parameters such as origin, axis, or radius. These are geometric surface classifications derived from the STEP body. Component names are stored in the catalogs as titles.

Views

Each part provides seven 1,000 × 1,000 pixel PNG views: isometric, positive and negative X, positive and negative Y, and positive and negative Z. Its view index stores camera position, target, up direction, view and projection matrices, clipping range, pixel convention, and the source geometry hash.

Potential applications

Nano provides paired inputs for prototyping and inspecting workflows such as:

Workflow	Relevant data
Drawing-to-solid retrieval	Drawing sheets, part views, STEP files, and component relationships
Engineering drawing understanding	Vector entities, text, dimensions, and rendered sheets
2D-to-3D reconstruction experiments	Paired drawings and supplied STEP reference solids
Geometry-based search and filtering	Face counts, surface inventories, bounds, volume, and area
Multi-view shape analysis	Seven views per part with camera metadata

Nano's 14 components make it suitable for format evaluation, pipeline development, and qualitative experiments. Evaluation results should identify the selected components and task setup.

Quick start

Download the complete package with the Hugging Face CLI:

hf download OrlaLabs/OrlaMechCAD-Nano --repo-type dataset --local-dir OrlaMechCAD-Nano
cd OrlaMechCAD-Nano

The Hub exposes each Parquet catalog as a separate configuration (parts, drawings, documents, part_measurements, and relationships). Each has one all split containing the complete table.

For programmatic access, install pyarrow and run the following from the dataset root. It loads the bracket's linked assets and their structured records:

from pathlib import Path
import json
import pyarrow.parquet as pq

root = Path(".")
parts = pq.read_table(root / "data/parts.parquet").to_pylist()
drawings = {
    row["asset_id"]: row
    for row in pq.read_table(root / "data/drawings.parquet").to_pylist()
}
documents = {
    row["asset_id"]: row
    for row in pq.read_table(root / "data/documents.parquet").to_pylist()
}

part = next(row for row in parts if row["external_id"] == "ORL-8ff18328a")
drawing = drawings[part["drawing_ids"][0]]
document = documents[drawing["document_ids"][0]]

step_path = root / part["step_path"]
dwg_path = root / drawing["source_path"]
pdf_path = root / document["pdf_path"]
faces = json.loads((root / part["faces_path"]).read_text())["records"]
dimensions = [
    record
    for record in json.loads((root / drawing["dimensions_path"]).read_text())["records"]
    if record["record_type"] == "dimension"
]
selected = [row for row in parts if row["face_count"] > 20]

print(part["title"], len(faces), len(dimensions))
# SLOTTED RIB BRACKET 28 28

Package structure

OrlaMechCAD-Nano/
├── README.md
├── LICENSE
├── schema.json
├── banner/                         Dataset banner image
├── data/
│   ├── drawings.parquet
│   ├── parts.parquet
│   ├── documents.parquet
│   ├── part_measurements.parquet
│   └── relationships.parquet
├── drawings/<drawing_id>/
│   ├── source.dwg
│   ├── drawing.dxf
│   ├── drawing.json
│   ├── dimensions.json
│   ├── texts.json
│   ├── title_block.json
│   ├── layers.json
│   ├── blocks.json
│   ├── geometry_summary.json
│   └── views/                      Sheet preview and view index
├── parts/<part_id>/
│   ├── geometry.step
│   ├── geometry_summary.json
│   ├── faces.json
│   ├── source_context.json
│   └── views/                      Seven part previews and view index
└── documents/<document_id>.pdf

The root folder name can vary by delivery. Catalog paths are relative to that root. View PNG paths inside per-asset view indexes are relative to the owning drawing or part directory.

Catalog	Rows	Purpose
drawings.parquet	14	Drawing identities, content summaries, artifact paths, and paired assets
parts.parquet	14	Solid identities, geometry measurements, artifact paths, and paired drawings
documents.parquet	14	Drawing PDF identities, page counts, and source relationships
part_measurements.parquet	14	Detailed geometry measurements and surface inventories
relationships.parquet	28	depicts_part and rendered_from links

Source identity and measurement conventions

The original ORL identifier is retained as external_id in the drawing, part, and document catalogs. Asset IDs use a type prefix and the first 24 hexadecimal characters of the source SHA256. Catalog artifact entries include relative paths, byte sizes, and full SHA256 hashes.

STEP geometry is supplied with each pair and recorded as origin: provided_step. The drawing-to-part links retain the sample pairing and principal dimension comparison. DWGs contain 2D mechanical drawing views; STEPs contain the corresponding 3D BRep solids.

STEP lengths, areas, and volumes are reported in mm, mm², and mm³ using source-declared units. Drawing coordinates follow the DWG unit declaration. CAD geometry inside a block retains that block's frame, with instance transforms recorded separately. Additional CAD entity types retain their native DXF attributes. The paired scale comparison covers principal sizes and representative features.

Verification and release

The packaged DWG, STEP, and PDF source assets preserve the supplied sample bytes. STEP solids have been reopened and checked for topology, validity, volume, area, and oriented bounds. All 91 part pairs have distinct measured volumes beyond the rigid-geometry comparison tolerance. Catalog references, JSON schemas, artifact hashes, PDF pages, and preview images have been checked locally.

Private build logs and verification receipts are kept outside the dataset package.

Release field	Value
Dataset family	OrlaMechCAD
Edition	OrlaMechCAD-Nano
Dataset version	1.0.0
Schema	orla-mech-cad 1.0.0
Build date	2026-10-18

License and attribution

OrlaMechCAD-Nano is licensed under Creative Commons Attribution-NonCommercial 4.0 International. See LICENSE for the full terms.

For attribution, use OrlaLabs, OrlaMechCAD-Nano, version 1.0.0, link to the dataset and the license, and indicate any changes as required by the license.

For commercial licensing and access to the larger OrlaMechCAD collection, contact Orla.