Chapter 3: Exploded Views & Notation Systems

Created by Sarah Choi (prompt writer using ChatGPT)

Exploded Views & Notation Systems for Prop Concept Artists: Dimensions, Standards, and Practical Reference

Exploded views are the Rosetta Stone of a prop. They show what the object is, what it is made of, and how it goes together—at a glance. A strong exploded drawing bridges concept intent and production reality by revealing part relationships, assembly order, and service logic without drowning the viewer in leader spaghetti. This article lays out a practical, principle‑driven approach to exploded views and notation systems so both concept and production artists can communicate dimensions, standards, and reference with confidence.

Exploded views are not merely pulled‑apart renders. They are structured compositions with hierarchy and rhythm. Begin by writing the “assembly story” in one sentence: what is the main path of construction or disassembly and why? This choice determines your explode axis and staging. A cartridge‑style battery bay explodes along a linear axis; a radial valve stack uses a starburst; a clamshell case uses a book‑open path. Keep your explode distances proportional to part size and importance; small hardware travels farther so it clears visually, major housings travel less so the silhouette remains recognizable.

View strategy and lens discipline come first. Orthographic three‑quarter is the workhorse because it preserves dimensions while showing depth. For camera settings, emulate a 35–50 mm full‑frame equivalent perspective if orthographic is not available; anything wider increases foreshortening and spoils measurement intuition. Lock one master view and reuse it for BOM, detail callouts, and torque sequences so reviewers build a stable mental model. If you must include a secondary view (section or underside), anchor it with common datums and a mini triad glyph that shows shared axes.

Explode axis and spacing require consistency. Choose one primary axis per assembly (X for longitudinal, Z for vertical) and secondary offsets only to avoid overprints. Space parts by a small multiple of their local feature size (e.g., 1.5–2.5× the largest fastener head in that neighborhood). Align separated parts on ghost rails that follow mating features—bosses to holes, pins to sockets—so the path of travel is obvious. Where parts rotate into place, arc them on phantom curves with tick marks for detents.

Trails and ghost geometry teach fit. Use thin, low‑contrast connector trails from each part to its installed position. Where tolerances matter, draw a faint phantom silhouette of the assembled state behind the exploded stack; this prevents the composition from becoming a floating parts poster. Show keys and anti‑rotation flats as they would align; show gasket compression direction and the order of o‑rings on shafts with tiny numbers printed along the shaft.

Balloons, item numbers, and the BOM convert art to inventory. Number parts clockwise and outside‑in, starting at the top left of the page or the first step in your assembly story. Keep numbers consecutive and never reuse an ID within a sheet. Balloons should be uniform: 7–9 mm circle for A3 sheets, 4–6 mm for A4; leader lines enter the part perpendicular to the silhouette for clarity. The BOM (Bill of Materials) should list Item, Qty, Part Name, Material/Finish, Spec (e.g., M4×10 BHCS), and Notes (e.g., torque 2.0 N·m, Loctite 243). Match capitalization and abbreviations across sheets.

Notation grammar avoids chaos. Adopt a limited symbol set and use it consistently: hex for specifications, circle for quantities, square for safety/lockout, triangle for alignment. Leader lines should prefer 45° and 0/90° segments; avoid curves unless they encode motion. Use two text sizes only: headers and body; keep body text ≥2.5 mm cap height for print legibility at A3. Define four line weights: outer silhouette (thick), part edges (medium), trails/leaders (thin), hatching/section (hairline). This simple palette keeps the sheet readable when printed or compressed.

Dimensions and datums belong to features, not edges. In an exploded view, dimension only what the assembly logic needs: clearance distances, fastener lengths, pitch circles, gasket cross‑sections, and wire harness lengths. Put full dimensional stacks on orthos and detail boxes; use the exploded sheet to direct attention to relationships and sequences. Establish datums (A, B, C) on mating faces and use centerlines for cylindrical stacks; this prepares the drawing for tolerance talk without drowning it in GD&T. If a dimension implies a standard (e.g., DIN rail 35 mm, 19″ rack width, 25 mm port pitch), state the standard explicitly once in the notes and echo it visually with a tiny gauge graphic.

Sections and details are clarity multipliers. Add local section cuts—half‑sections through bearings, seals, dovetails—to show hidden features. Keep section hatching at a consistent angle and weight; alternate angles for adjacent parts. Detail bubbles (A, B, C) should scale 2–3× and live near the main view with leader tails that do not cross other leaders. Use phantom cuts rather than global halves when only one area needs exposition; this preserves the overall silhouette.

Assembly order and torque patterns deserve choreography. Number steps big and bold near the region where they apply. For ring fasteners, draw a torque sequence diagram: numbers arranged around the circle with a faint arrow indicating alternation (1‑3‑5 / 2‑4‑6). For multi‑stage assemblies, break the sheet into horizontal bands (Stage 1: chassis, Stage 2: drivetrain, Stage 3: covers) with thin separators and persistent item numbers. Where adhesives or thread lockers are used, place a droplet icon at the joint and itemize the spec in notes.

Materials, finishes, and processes inform both look and wear. In the BOM, include material shorthand (AL 6061‑T6, PC‑ABS, 304 SS) and finish (anodize Type II black matte, powder coat RAL 7016, zinc‑nickel). On the view, cue finishes with subtle rendering: satin for anodize, slight orange peel for powder, sharper specular for machined metal. Add a tiny swatch strip on the sheet showing the palette so downstream painters and shader artists can match.

Color and contrast should carry hierarchy, not rainbow noise. Reserve accent color for alignment arrows, motion arcs, safety notes, and step headers. Keep parts in neutral materials so callouts pop. If the world uses faction livery, reflect it only on outer shells; internal parts should remain neutral so clarity wins. For dark‑mode sheets, invert lines accordingly and test print once; many studios still annotate on paper.

Localization and language‑free design protect you downstream. Use icons and letter codes; keep sentences terse and stack multilingual lines if required. Avoid long strings in balloons. Provide a glossary for abbreviations: BHCS (button head cap screw), SHCS (socket head cap screw), NPT, BSPP, ID/OD. If right‑to‑left readers are expected, keep the numbering scheme independent of reading order (radial numbering rather than left‑to‑right).

Exploded animations and rigs help sell function. If deliverable includes motion, rig parts with constraints that mirror real fasteners and joints: screws translate/rotate, pins follow rails, hinges arc with limits, springs lengthen with guides. Time the explode so small fasteners move first, majors last; reassemble in reverse. Keep one camera; let parts do the dancing. Export a poster frame as the static exploded view to unify still and motion deliverables.

Digital pipeline and file hygiene make reuse painless. Name layers by Item number + Part name. Group hardware separately (FASTENERS), rubber/seals (SEALS), electronics (PCB, CABLES). Keep vectors for balloons and leaders on their own layer so translators can swap text without touching art. Provide both a layered source (AI/PSD/FIG) and flattened export (PDF/PNG) at 300 dpi for A3. Include a CSV BOM with matching Item numbers so producers can ingest quickly.

Common mistakes undermine trust: exploded distances too large (parts feel unrelated), inconsistent axes (chaos), leaders crossing leaders (spaghetti), missing quantities in BOM, item numbers that skip, over‑rendered materials that hide edges, dimensions to paint rather than to the part, and unlabeled standards that the audience must guess. Avoid perspective that exaggerates small parts; your fastener heads will look unusably tiny.

Reference anchors belong on every sheet: a 100 mm scale bar, an AA cell silhouette, and a human hand outline at 100% for grip‑relevant assemblies. Include camera/FOV settings for 3D exports and a note on units (“All dimensions in millimeters unless noted”). If you used a known standard (e.g., 25 mm port spacing), draw a tiny gauge graphic once to make the reference visual, not just textual.

Checklists that downstream teams love:

— Story: one‑line assembly intent; explode axis defined. — View: locked lens/FOV; orthographic preferred. — Hierarchy: silhouette preserved; small parts travel farther. — Trails: rails align pins/holes; phantom assembled ghost. — Balloons: consecutive numbers; leaders clean; quantities in BOM. — Dimensions: only relationships here; full stacks in orthos/details. — Sections: local cuts for hidden features; consistent hatching. — Steps: torque/sequence diagrams; adhesives and specs marked. — Materials: BOM lists material/finish; palette swatch strip present. — Reference: scale bar; units; camera note; hand/AA anchors as needed. — Files: layered source + PDF; CSV BOM; font and icon set included.

Exploded views and notation systems are empathy made visible. They respect the assembler, the modeler, the rigger, the shader artist, and the fabricator by telling a clear story with just enough numbers. When your sheet preserves silhouette, stages parts along believable rails, labels with discipline, and anchors to real‑world standards, your prop leaps from compelling image to buildable machine—no translator required.