COGWRIGHT

Field Instrument FI-104 · v2.3.1

COGWRIGHT is a local-first mechanical transmission design, geometry, and fabrication-preparation instrument. Version 2.3.1 adds a simple-first workflow: the application opens directly in a clean Gear Generator, while system design, optimization, fabrication, inspection, and integration tools remain available in grouped navigation. COGWRIGHT generates physical-dimension SVG profiles, shaft plates, fabrication packages, process assessments, dimensional inspection plans, and first-article qualification records. The application is delivered as one self-contained HTML file with no server, build system, external library, or network requirement.

COGWRIGHT is intended to feed fabrication geometry and project metadata into Cutline, CutPlanner, and Cooper through the shared Field Instrument transfer contract.

v2.3.1 Simple-First Workflow

COGWRIGHT now opens in the Gear Generator rather than the Design Optimizer or Transmission Workbench. The default part is a clean 24-tooth module 2 spur gear with an 8 mm round bore, no mating gear, no lightening holes, and construction geometry hidden.

The Gear Generator has two interface levels:

• Basic: module or diametral pitch, tooth count, pressure angle, bore, optional mating gear, validation, export, and Parts Tray actions
• Advanced: profile shift, backlash, resolution, root fillet, tip relief, keyways, hub features, set-screw marks, mounting holes, and counterbore guides

The left navigation is organized into three workflow groups:

1. Create a Part
2. Build a System
3. Make & Verify

Only one navigation group remains expanded at a time. Quick actions connect the Gear Generator directly to Fabrication Setup, the Parts Tray, and Gear Train design. See WORKFLOW_REVIEW.md for the design rationale.

v2.3 Material and Process Intelligence

Version 2.3 evaluates generated geometry against indicative workshop material and process profiles.

Assessment sources

• Complete Transmission Workbench assembly
• Current generator or system profile
• Every active Parts Tray record
• Optional manual force input
• Propagated Workbench torque and service-factor load estimates

Material profiles

• Birch plywood
• Cast acrylic
• Acetal or POM
• 6061 aluminum
• Mild steel
• PLA
• PETG
• Nylon
• HDPE

Process profiles

• CO2 laser
• Diode laser
• CNC router
• CNC mill
• Waterjet
• FDM printing
• Resin printing

Screening checks

• Material/process compatibility
• Tool, kerf, or nozzle resolution
• Minimum hole and web
• Minimum tooth pitch
• Inside-corner radius
• Thickness envelope
• Duty cycle and design cycles
• Humidity, outdoor, and warm-environment cautions
• Preliminary force utilization
• Hub and shaft-attachment strategy

Each component receives a risk score, findings, and recommendations. The complete assessment receives a 0–100 fabrication-risk score, where lower is better.

Workflow integration

• Apply recommended starting values to Fabrication Setup
• Export a Markdown assessment report
• Save up to 30 project-local assessments
• Include the report in fabrication-package ZIP files
• Include assessment data in Cooper transfers
• Export a compact SVG assessment dashboard

See MATERIAL_PROCESS_INTELLIGENCE_NOTES.md for calculation logic, assumptions, process boundaries, and safety limitations.

v2.2 Design Optimization

Version 2.2 searches ranked one- through four-stage gear, timing-belt, chain, and mixed-family transmissions. Alternatives can be ranked for ratio accuracy, package size, engagement, unique profiles, and standard components, then reconstructed as complete editable Workbench assemblies.

v2.1 Parametric Assemblies

Version 2.1 adds named variables, restricted mathematical formulas, dependency-driven Workbench regeneration, design configurations, broken-reference detection, and revision snapshots.

v2.0 Transmission Workbench

Version 2.0 turns COGWRIGHT from a collection of related generators into a connected mechanical transmission system designer.

Visual assembly canvas

The Transmission Workbench supports:

• Draggable, grid-snapped shaft centers
• Locked and movable shafts
• Bearing and shaft-diameter definitions
• Gears, timing pulleys, smooth pulleys, sprockets, and bearings
• External gear, internal gear, timing-belt, smooth-belt, and chain connections
• Compound shafts carrying components in separate axial planes
• Automatic layout and fit-to-workbench controls
• Optional component envelopes, bearing geometry, and load indicators

The default project demonstrates a coherent three-stage transmission with an 18:1 overall reduction.

System calculations

The workbench propagates calculations from a selected input shaft to a selected output shaft:

• Stage and overall ratio
• Shaft speed
• Estimated torque
• Stage and overall efficiency
• Relative rotation direction
• Output power
• Preliminary radial-force indicators
• Center-distance and transmission-path checks

The system graph supports multiple stages and compound shafts. Disconnected branches remain editable but are excluded from the selected input-to-output result.

Compatibility and packaging checks

COGWRIGHT now reports system-level conditions including:

• Gear module and pressure-angle mismatches
• Timing-profile incompatibility
• Chain-standard incompatibility
• Incorrect shaft center distances
• Axial-plane misalignment
• Unintended component-envelope collisions
• Low timing-pulley or sprocket engagement
• Missing input-to-output paths

These checks are preliminary geometric checks. They do not replace tooth stress, shaft, bearing, belt, chain, guarding, or machine-safety analysis.

Assembly and fabrication outputs

Version 2.0 adds:

• System assembly SVG
• Fabrication-ready shaft-plate SVG
• System calculation report
• Conversion of all workbench components into Parts Tray records
• Workbench geometry as a Cutline source
• Workbench parts and quantities in CutPlanner packages
• System calculations and assembly context in Cooper documentation transfers

The shaft-plate output includes bearing or shaft openings, center marks, labels, and persistent manufacturing-operation layers.

See TRANSMISSION_WORKBENCH_NOTES.md for formulas, assumptions, compatibility logic, and engineering boundaries.

v1.9 Inspection and Qualification

Version 1.9 adds an inspection workspace that connects generated geometry to measurable workshop evidence.

Qualification sources

An inspection plan can be generated from:

• The current generator workspace
• Any active stored part in the Parts Tray
• The original parametric and fabrication metadata retained with a stored part

The inspection source, project identity, part revision, material, and geometry type are preserved in saved records and exported packages.

Feature-specific measurement plans

COGWRIGHT builds an inspection worksheet from the selected geometry. Common checks include:

• Overall width and height
• Material or assembled stack thickness
• Bore or shaft-opening size
• Keyway width and depth
• Outside diameter
• Radial runout

Generator-specific checks are added where the source geometry supports them:

• Involute gear outside and root diameters
• Chordal tooth thickness
• Base-tangent span across a calculated number of teeth
• Measurement over pins using an ideal or user-selected measuring-pin diameter
• Sprocket roller-pocket fit gauge and pitch-diameter reference
• Timing-pulley outside and pitch-diameter references
• Geneva slot width, rack length, and other mechanism-specific dimensions

Reference dimensions that cannot be accepted directly with an ordinary caliper are explicitly labeled as reference calculations.

Tolerances and disposition

Four tolerance modes are available:

• Prototype
• Standard
• Precision
• Custom

General linear, bore/internal, tooth/profile, and material-thickness tolerances remain independently adjustable. Each recorded actual value is evaluated as pass, fail, or pending. The resulting record receives a PASS, FAIL, or INCOMPLETE disposition.

These configurable values are workshop acceptance bands. They do not claim an AGMA, ISO, ASME, customer, or accredited laboratory quality grade.

First-article traceability

Inspection records include:

• Inspection type
• Inspector
• Date
• Lot or batch
• Serial or article identifier
• Measurement instrument
• Calibration-due date
• Inspection notes and disposition

Up to 50 inspection records are retained in the project. A saved record can be reloaded into the worksheet or deleted from the inspection history.

Inspection outputs

Version 1.9 exports:

• Measurement worksheet CSV
• First-article inspection report in Markdown
• Machine-readable inspection record JSON
• 1:1 inspection-template SVG
• Source-part SVG
• Complete qualification-package ZIP

The SVG template includes a 50 mm calibration bar, source profile, optional construction geometry, and bore low/nominal/high reference circles. Templates must be printed or plotted at 100 percent and checked against the calibration bar before use.

Inspection records are also added to the complete fabrication package and Cooper documentation payload.

See INSPECTION_QUALIFICATION_NOTES.md for formulas, measurement assumptions, and qualification boundaries.

v1.8 Chain Drives

Version 1.8 rebuilds the sprocket generator as a complete chain-drive design and fabrication workspace.

Chain libraries

The built-in reference library includes:

• ANSI #25, #35, #40, #41, #50, #60, #80, #100, and #120
• ISO 06B, 08B, 10B, 12B, and 16B
• Bicycle 1/2 × 1/8 and 1/2 × 3/32 envelopes
• Fully custom pitch, roller diameter, and inner width

Selecting a preset applies pitch, roller diameter, nominal inner width, descriptive metadata, and a preliminary chain-speed guidance value. Manufacturer dimensions and current standards remain authoritative for final component selection.

Drive calculations

The two-sprocket drive workspace calculates:

• Transmission ratio
• Pitch and outside diameters
• Geometric chain length in pitches
• Slack-adjusted design length
• Permitted even-link count
• Optional odd pitch count using an offset or half link
• Center distance from a selected link count
• Driver and driven wrap angles
• Estimated engaged teeth
• Driver chain speed
• Maximum driver RPM at the configured speed limit
• Articulation angle
• Chordal or polygonal speed variation

The link solver supports a configurable slack allowance. Without an offset-link allowance, selected chain length is constrained to an even pitch count.

Idlers and tensioners

An optional upper-span tensioner can be added as:

• A smooth roller
• A toothed sprocket layout

COGWRIGHT solves common tangents, revised path length, wrap, and idler contact. The toothed-idler option is explicitly treated as a fabrication and packaging approximation. Final designs must verify chain side, tooth entry, adjustment travel, bearing loads, and tensioner direction.

Single, duplex, and triplex construction

The same profile can be configured for one, two, or three strands. Layered kit output can generate:

• One full sprocket plate per strand
• Spacer discs between strand plates
• Optional hub-insert discs
• Nominal stack-width reporting
• Separate driver or driven kits

Axial chain spacing is not established solely by a two-dimensional SVG. Verify plate thickness, spacer stack, hub hardware, chain inner width, and strand center spacing against the selected chain.

Split service sprockets

Version 1.8 adds two distinct service features:

• A radial split-hub clamp slot
• A complete two-piece body split with clamp-hole locations

These are fabrication aids, not a structural certification. Verify balance, fastener preload, remaining hub section, tooth indexing, and reassembly accuracy.

See CHAIN_DRIVE_NOTES.md for formulas, assumptions, and engineering boundaries.

v1.6 Gear Pairs and Gear Trains

Version 1.6 adds a complete gear-train workspace for building and analyzing up to four compound stages.

Supported stage arrangements

• External gear pairs
• External pairs with an idler gear
• Pinion and internal-ring pairs
• Compound shafts, where one stage's driven gear shares a shaft with the next stage's driver
• Automatic or manually overridden stage orientation

Train calculations

• Stage ratio and overall reduction
• Pitch diameters and pitch-center distances
• Input and output speed
• Estimated output torque using a user-defined per-mesh efficiency
• Direction of rotation through the complete train
• Number of active gear meshes
• External contact ratio
• Estimated internal-mesh contact ratio
• Hunting-tooth and common-factor checks
• Difference between the requested and actual overall ratio

The ratio engine treats idlers correctly: an idler changes direction and packaging but not the magnitude of the stage ratio. Internal meshes preserve direction, while external meshes reverse direction.

Ratio Finder

The Ratio Finder searches practical two-stage tooth combinations around the requested reduction and ranks the closest solutions. Recommendations can be applied directly to the current train. The result cards report:

• Overall ratio
• Percentage error from the target
• Tooth counts by stage
• Approximate packaging span
• Common-factor cautions

Assembly and fabrication outputs

Two distinct views are provided:

• Meshed assembly places gears on calculated shaft centers and shows rotational direction, shaft labels, pitch circles, and stage relationships.
• Parts strip separates every generated gear into a nonoverlapping fabrication layout suitable for export and downstream nesting.

Every train component can be added to the parts inventory as its own revision-aware part. Compound gears that share a shaft remain separate physical components so they can be fabricated at the correct axial layer.

Internal-ring geometry

Internal gears are generated as fabrication-oriented radial inversions of the corresponding involute pinion-space construction. The profile is closed, finite, and checked for self-intersection, but it is not a certified hob, shaper, or proprietary cutter form. Critical load-bearing ring gears should be verified against a recognized gear standard and the intended manufacturing process.

v1.7 Advanced Mechanisms

Version 1.7 adds a dedicated workspace for flat mechanisms that can be meaningfully represented as physical-dimension SVG geometry.

Included generators

• Standalone internal gears using the involute-derived ring profile introduced with the gear-train workspace
• Straight gear racks with module, pressure-angle, body-depth, mounting-hole, and matching-pinion controls
• Ratchet wheels and pawls with directional sawtooth geometry and separate pawl profiles
• Geneva indexers with calculated driven slots, crank radius, index angle, drive-pin clearance, and separate driver disk
• Cycloidal-style gears for low-load visual and clockwork prototypes
• Lantern pinion plates with two plate profiles, shaft bores, pin-circle holes, and dowel counts
• Escapement wheels with adjustable pointed-tooth lean and root depth
• Noncircular gears based on an elliptical pitch curve with teeth distributed by arc length and offset along local normals

Rack and pinion outputs

The rack generator offers three views:

• Rack only
• Rack and matching pinion as separated fabrication parts
• A meshed assembly view with the pinion placed on the rack pitch line

The assembly view is for packaging and motion review. The separated-parts view is the appropriate choice for cutting.

Geneva calculations

For a center distance C and N driven slots, COGWRIGHT uses:

crank radius = C × sin(π / N)
locking reference radius = C × cos(π / N)
index angle = 360° / N
slot width = drive-pin diameter + 2 × clearance

The driven-wheel slot profile and drive-pin location are generated as cut geometry. The locking-cam circle is construction guidance, not a completed production cam design.

Explicit profile boundaries

Not every historic mechanism has one universal production tooth form. COGWRIGHT identifies these boundaries directly in the interface and SVG metadata:

• Internal gears are involute-derived fabrication profiles rather than cutter-certified ring gears.
• Cycloidal-style gears are smooth workshop profiles, not certified clock-wheel cutter geometry.
• Escapement wheels require pallet, lock, drop, impulse, and material-specific design beyond the wheel outline.
• Noncircular gears do not yet generate a mathematically conjugate mating gear.
• Geneva locking cams require duty-cycle, impact, dwell, and clearance engineering.

See ADVANCED_MECHANISM_NOTES.md for the detailed assumptions.

Involute Gear Workspace

• Module or diametral-pitch input
• 14.5°, 20°, and 25° pressure angles
• Profile shift, backlash, root fillet, and tip relief
• Draft through ultra contour resolution
• Bore, keyway, bolt-circle, lightening-hole, and hub features
• Optional mating gear
• Pitch, base, outside, root, and center-distance calculations
• Circular and chordal tooth-thickness measurements
• Undercut, pointed-tooth, root-overlap, and bore-envelope warnings

Timing and Smooth Pulley Drives

Timing families

• 2GT
• 3GT
• HTD 3M
• HTD 5M
• HTD 8M
• MXL
• XL
• T2.5
• T5
• AT5

Timing mode calculates pulley pitch diameters, ratio, stock or custom belt length, center distance, wrap, engaged teeth, and optional backside-idler routing. It supports nominal/CNC, laser-cut stack, and 3D-print fabrication intents, plus flange plates, toothed core layers, and hub inserts.

Curvilinear timing profiles are workshop-oriented approximations rather than manufacturer-certified proprietary tooth forms. See TIMING_PROFILE_NOTES.md.

Smooth mode supports open and crossed drives, take-up allowance, flange clearance, wrap, straight spans, and reverse center-distance solving.

Roller-Chain Sprockets

• ANSI, ISO B-series, bicycle, and custom chain envelopes
• Single, duplex, and triplex strand construction
• Driver and driven sprocket profiles
• Link-count and center-distance solving
• Slack and offset-link handling
• Wrap and engaged-tooth estimates
• Chain-speed and chordal-action guidance
• Smooth or toothed idler layouts
• Split-hub and complete two-piece service splits
• Layered sprocket, spacer, and hub-insert kits
• Roller-pocket, root-web, and tooth-land checks

The sprocket contour is a practical fabrication profile. It is not a certified ANSI, ISO, bicycle, hob, or proprietary cutter form.

Fabrication Controls

• Kerf or cutter-width compensation
• Independent external and internal allowances
• Press, transition, nominal, slip, loose, and custom fit presets
• Process presets for laser cutting, CNC work, and FDM printing
• Round, D, double-D, hexagonal, and square bores
• Keyways, set-screw pilots, split-hub score lines, and radial split slots
• Bolt circles, counterbore guides, center marks, axes, labels, grain marks, and registration holes
• Material and thickness metadata
• Separate cut and marking stroke widths

SVG files use persistent manufacturing groups:

CUT_OUTSIDE
CUT_INSIDE
DRILL_MARKS
SCORE
ENGRAVE
CONSTRUCTION

Parts and Project Workflow

• Project name, code, revision, owner, and notes
• Named parts, families, variants, revisions, and categories
• Quantities, material, thickness, and fabrication notes
• Locking, archiving, duplication, deletion, search, filtering, and reordering
• Parametric reload of stored parts into their originating generator
• Quantity-aware material sheets
• Individual part SVG export
• BOM CSV and cut-list CSV
• Project summary Markdown
• Complete local fabrication-package ZIP
• Editable .cogwright project import and export

Field Instrument Transfers

COGWRIGHT uses:

field-instrument-transfer/v1.0

Cutline

Receives the current geometry or selected material sheet as manufacturing-layer SVG with part, project, material, tolerance, and operation metadata.

CutPlanner

Receives all active parts, quantities, materials, thicknesses, rotation and grain restrictions, individual SVGs, arranged material sheets, BOM, and cut list.

Cooper

Receives the project summary, BOM, cut list, manifest, validation results, fabrication metadata, and optional part geometry for documentation generation.

Delivery is attempted through same-origin storage, route query parameters, BroadcastChannel, and postMessage. SVG or JSON download remains the guaranteed fallback. Receiver implementation details are in FIELD_INSTRUMENT_TRANSFER.md.

Local Operation

Open index.html in a modern desktop browser. All calculations, SVG generation, project storage, ZIP creation, and exports occur locally. Browser local storage provides autosave; exporting a .cogwright file provides a portable editable backup.

Validation

Version 2.3 includes 82 built-in diagnostics, covering the complete existing geometry and transmission suite plus:

• Workbench-wide material/process assessment
• Tool-diameter and inside-radius rules
• Material/process incompatibility blocking
• Component-level load-utilization calculations
• Material/process report generation
• v2.3 assessment SVG metadata
• Parametric, optimizer, Workbench, inspection, transfer, and package regression checks

The release also passes JavaScript syntax validation, duplicate DOM-ID inspection, single-file dependency inspection, SVG parsing, ZIP integrity validation, and automated browser interaction testing for compatible and deliberately incompatible material/process combinations without runtime exceptions.

Engineering Boundary

COGWRIGHT prepares geometry and performs preliminary mechanism calculations. It does not certify load capacity, fatigue life, tooth bending stress, contact stress, shaft strength, bearing life, belt tension, chain pull, guarding, or machine safety. Estimated torque assumes ideal ratio multiplication reduced only by the selected per-mesh efficiency. Verify critical mechanisms using applicable standards, manufacturer data, engineering analysis, and physical inspection.

Turkey

Turkey remains a whimsical cog-and-spring oracle. It may comment on the project, but it cannot generate geometry, alter dimensions, approve a design, or replace engineering judgment.