Autocad Mechanical Drawing Reconstruction

AutoCAD Mechanical Drawing Reconstruction

Core Rule

Treat successful file generation as the start of verification, not completion. Do not claim a drawing matches the reference until it has been reopened or rendered and checked against the source.

Required Workflow

1. Read all supplied requirements and inspect every reference image at full resolution.
2. Build a feature inventory for each drawing:
   • views and section conventions
   • explicit dimensions and tolerances
   • diameters, radii, chamfers, grooves, holes, and threads
   • roughness symbols, technical notes, material, title block, and BOM
3. Separate information into:
   • confirmed: explicitly visible or dimensioned
   • inferred: supported by projection relationships or another drawing
   • unknown: blurred, hidden, or not dimensioned
4. Draw confirmed geometry first. Use inferred geometry only when necessary and record the assumption.
5. Generate or edit the CAD file using native entity types.
6. Render or reopen every output and compare it side by side with the reference.
7. Correct all confirmed errors, regenerate, and repeat verification.
8. Deliver DWG/DXF files only after the final validation pass.

Entity Requirements

• Use LINE for straight edges. Do not approximate straight edges with curves or segmented polylines.
• Use ARC or CIRCLE for radii and circular features. Do not approximate round corners with straight segments.
• Use native HATCH entities for section lining. Keep hatching inside section boundaries.
• Use centerline linetypes for axes and centers.
• Use proper arrowheads and leaders. Every note must point to its corresponding feature.
• Prefer associative AutoCAD dimensions and leaders when the environment supports them.
• Keep outline, thin, center, dimension, hatch, text, and border entities on appropriate layers with suitable lineweights.

Annotation Rules

• Match the reference annotation text exactly when legible.
• Do not invent dimensions, notes, labels, dates, or manufacturing requirements.
• Place diameter notes on cylindrical features, radius notes on arcs, chamfer notes on chamfers, and roughness symbols on the specified surfaces.
• Check the arrowhead landing point, not only the text.
• Prevent text, extension lines, leaders, and dimensions from overlapping.
• Preserve the reference's annotation hierarchy and approximate placement where practical.

Geometry Interpretation

• Identify full views, half views, half sections, local sections, and broken views from centerlines, hatch boundaries, projection position, and visible/hidden edges.
• Never decide that a feature is a full circle or semicircle from appearance alone. Confirm it using the source image and projection conventions.
• Use explicit dimensions as ground truth.
• Use related part and assembly drawings to resolve ambiguous features, but keep repeated part geometry consistent across all drawings.
• When a feature cannot be confirmed, state that limitation instead of presenting an estimate as exact.

Cross-Drawing Consistency

After changing any shared part:

1. Check its part drawing.
2. Check every assembly view containing it.
3. Check mating dimensions and interfaces.
4. Check BOM item number, name, and quantity.

Do not accept a locally correct part that conflicts with the assembly.

Validation Checklist

Read references/validation-checklist.md and complete every applicable item before delivery.

At minimum, verify:

• every required view exists and uses the correct view/section convention
• every legible source annotation exists and points to the correct feature
• arcs, circles, straight lines, hatches, centerlines, and leaders use correct native entities
• section lines do not cross holes or non-sectioned regions incorrectly
• no duplicate, disconnected, or unintended lines exist
• no annotation overlaps or obvious layout collisions remain
• part and assembly geometry agree
• text renders correctly without missing-font or encoding issues
• final DWG/DXF files reopen successfully

Reporting

Report confirmed corrections and remaining uncertainty separately. Never say "fully identical" or "complete match" when the source is blurred, perspective-distorted, incomplete, or lacks dimensions.