AI Skill Report Card
Generating Prototype Technical Drawings
Quick Start14 / 15
Before producing any drawing, confirm four parameters with the user. Do not assume defaults silently — ask, but propose a sensible recommendation so the user can just say "yes" or correct it.
Clarification template to send first:
To generate this drawing correctly, please confirm:
1. DISCIPLINE — which of the four?
[ ] Detail Drawing (single part, fully dimensioned/toleranced)
[ ] Assembly Drawing (multiple parts, BOM, relationships)
[ ] Schematic Drawing (functional/logical, not to scale)
[ ] Layout / General Arrangement (overall spatial arrangement, siting)
2. PROJECTION / VIEW STYLE — recommend based on discipline (see table below),
but confirm:
[ ] Orthographic (multiview: front/top/side)
[ ] Isometric / Pictorial (3D-style single view)
[ ] Section View needed? (full / half / offset / revolved)
3. STANDARD — ISO 128 / ISO 8015 (default/preferred) or ANSI/ASME Y14.5,
or another regional standard?
4. AUDIENCE — who reads this drawing? (changes notation, tolerance callouts,
notes verbosity, title block content)
[ ] Machinists / fabricators / CNC operators
[ ] Technicians / assembly teams / quality inspectors
[ ] Architects / project planners / site contractors
[ ] Multi-disciplinary / mixed audience
Only proceed to drafting once these are confirmed (explicit answers, or user says "use your best judgement" — in which case state the assumptions made at the top of the output).
Recommendation▾
Add a third example showing a Schematic drawing discipline (currently only Detail and Layout are covered, leaving Assembly and Schematic underrepresented in concrete examples)
Discipline → Recommended Projection Defaults
| Discipline | Primary Projection | Typical Sections | Scale Note |
|---|---|---|---|
| Detail Drawing | Orthographic multiview (3rd angle ISO / 1st angle if ISO region) | Full/half section common for internal features | To scale, exact dims required |
| Assembly Drawing | Isometric/pictorial overview + orthographic sub-views | Exploded view often substituted for section | May be NTS with callout |
| Schematic Drawing | Neither strictly — symbolic/topological | Rarely sectioned; flow/connectivity matters | Not to scale (NTS) |
| Layout / GA Drawing | Orthographic plan + elevation views | Building/site section for architecture | To scale, often reduced (e.g., 1:50, 1:100) |
State the recommended default, then explicitly ask: "Shall I proceed with [X] projection, or would you prefer [Y]?"
Workflow15 / 15
Progress:
- [ ] 1. Gather intent: what object/system, what it's for, what stage (prototype/pre-production)
- [ ] 2. Confirm discipline (Detail / Assembly / Schematic / Layout)
- [ ] 3. Confirm projection style + section view need
- [ ] 4. Confirm standard (ISO default, or ANSI/other)
- [ ] 5. Confirm audience
- [ ] 6. Draft title block + sheet metadata
- [ ] 7. Produce drawing (as ASCII/SVG/description + structured spec) with proper views
- [ ] 8. Apply dimensioning, tolerancing, annotations per audience/standard
- [ ] 9. Add BOM/parts list if Assembly; add legend if Schematic; add key plan if Layout
- [ ] 10. Review pass: check completeness against discipline checklist below
Step 1 — Gather Intent
Ask: What is being drawn? Is this a mechanical part, a built assembly, an electrical/fluid/process system, or a site/building arrangement? What manufacturing or construction process will consume this drawing (CNC milling, welding, PCB assembly, sheet-metal, site construction, etc.)?
Step 2–5 — Confirmation
Use the Quick Start template. Never skip silently — if the user gave partial info, ask only for the missing pieces.
Step 6 — Title Block (always include)
Minimum fields regardless of standard:
- Drawing title / part or assembly name
- Drawing number / revision
- Scale (or "NTS")
- Projection symbol (ISO: truncated cone symbol indicating 1st- or 3rd-angle)
- Date, author/drafter, approved-by (leave blank fields for prototype stage)
- Units (mm default under ISO; confirm if imperial needed)
- Material (Detail drawings only)
- Sheet size (A4/A3 for ISO; ANSI A/B/etc. if requested)
Step 7 — Produce the Drawing
Output as a structured text/SVG/diagram description including:
- View layout (which views, their arrangement per 1st/3rd angle convention)
- Labeled view names (FRONT, TOP, RIGHT / or PLAN, ELEVATION for architectural)
- Centerlines, hidden lines (dashed), visible outlines (solid/bold), section cutting planes (phantom line + arrows + letters, e.g., "A-A")
- Hatching convention for sections (ISO: 45° hatch lines, alternating direction per adjacent part)
Step 8 — Dimensioning & Annotation (audience-driven)
| Audience | Emphasis |
|---|---|
| Machinists/CNC | Full GD&T, datums, tight tolerances, surface finish symbols, material callouts, stock size |
| Assembly/QA/Technicians | Fit/clearance call-outs, torque specs, fastener callouts, inspection points, step-by-step sequence numbers on exploded views |
| Architects/Contractors | Overall dimensions, grid lines, elevation markers, room/zone labels, code/compliance notes, material finish schedules |
| Multi-disciplinary | Layered/tiered notes — critical dims prominent, secondary technical detail in call-out boxes or separate sheets |
Step 9 — Discipline-Specific Additions
- Assembly: numbered balloons tied to BOM table (item no., qty, description, material/part no.)
- Schematic: legend/key for symbols, signal/flow direction arrows, no physical scale implied
- Layout/GA: north arrow (if site), key plan/locator, grid/axis reference, revision cloud for prototype iterations
Step 10 — Review Checklist (discipline-specific)
Detail: ✅ fully dimensioned, no redundant dims, tolerances stated, material/finish noted, all views necessary (no superfluous views) Assembly: ✅ all parts balloon-tagged, BOM matches balloons, exploded/assembled state clear, fasteners specified Schematic: ✅ all symbols in legend, flow direction unambiguous, no conflicting symbol standards mixed Layout/GA: ✅ scale stated, north arrow if applicable, overall envelope dimensions, reference to detail/assembly sheets
Recommendation▾
Show a 'bad outcome' example (e.g., mismatched angle-of-projection symbol) to reinforce the pitfalls section with a concrete before/after
Examples16 / 20
Example 1: Input: "I need a drawing of a machined aluminum bracket for CNC milling, ISO standard." Output:
Confirmed: Discipline = Detail Drawing. Projection = Orthographic (3rd angle
recommended for ISO? Note: ISO defaults to 1st angle — confirm). Section =
likely not needed unless bracket has internal bore — asked user, confirmed
half-section for counterbore holes. Audience = Machinists/CNC operators.
Output: 3-view orthographic (FRONT, TOP, RIGHT) + one half-section view "A-A"
revealing counterbore depth. Title block: ISO 1st-angle symbol, Material:
Al 6061-T6, Scale 1:1, Units mm. Full GD&T: flatness on base face,
positional tolerance ±0.1mm on bolt holes, surface finish Ra 1.6 on mating
face. Dimensions: overall envelope, hole pattern PCD, counterbore dia/depth.
Example 2: Input: "Site layout for a small warehouse extension, for contractors." Output:
Confirmed: Discipline = Layout/General Arrangement. Projection = Orthographic
(Plan view + two Elevations). Section = building cross-section requested by
user for roof pitch. Standard = ISO (metric). Audience = Architects/contractors.
Output: Plan view at 1:100 with grid lines (A-D, 1-6), north arrow, overall
building envelope dims, door/window openings labeled. Two elevations (North,
East) at 1:100. One building section B-B at 1:50 showing roof pitch and
floor-to-ceiling heights. Title block includes revision cloud marking
"PROTOTYPE - FOR REVIEW, NOT FOR CONSTRUCTION."
Recommendation▾
Trim some redundancy between the Quick Start checklist and Step 2-5 workflow section, which largely restates the same confirmation process
Best Practices
- Always mark prototype/pre-production drawings clearly: "NOT FOR PRODUCTION" / "PRELIMINARY" watermark or title-block note — this is pre-production standard, not final release.
- Default to ISO conventions (1st-angle projection, mm units, ISO hatching) unless user specifies otherwise, but always state the assumption.
- Match line weight/line type conventions to the standard: continuous thick = visible edges, dashed thin = hidden edges, chain thin = centerlines, chain thick at ends = cutting plane.
- Keep one discipline per drawing. If a request blends disciplines (e.g., "assembly with full part tolerances"), recommend splitting into an Assembly sheet + separate Detail sheets, and say so.
- For exploded isometric assembly views, order parts along a logical assembly axis and number balloons sequentially in assembly order, not spatial position.
- Tailor note density to audience — CNC machinists want precision, architects want context; don't over/under-annotate.
Common Pitfalls
- Don't default to ANSI/3rd-angle without asking — ISO is the stated preference and uses 1st-angle by convention; mismatched angle-of-projection symbol vs. actual view arrangement is a common, serious error.
- Don't mix schematic and physical-scale conventions — schematics are NOT to scale and should never carry precise dimensions.
- Don't omit the projection symbol — ambiguity between 1st/3rd angle is a leading cause of manufacturing error.
- Don't add GD&T/tolerance depth meant for machinists onto an architectural GA drawing, or vice versa — match annotation style to confirmed audience.
- Don't proceed past Quick Start confirmation on assumptions alone without flagging them explicitly in the output.
- Don't forget the BOM-to-balloon consistency check on assembly drawings — mismatches are a frequent QA failure point.