NeoGrid OpenSCAD Code Generation

Generates OpenSCAD code for 3D-printed connectors that join store-bought divider materials (MDF, plywood, acrylic) into custom drawer organization layouts.

Required Reading Before Generating Code

CRITICAL: NeoGrid is a HYBRID system:

• 3D-print: Connectors only (~50g filament per piece)
• Buy/cut: Divider material (MDF, plywood, acrylic, uPVC) from hardware store

Official NeoGrid 2.0 implementation:

• QuackWorks GitHub: https://github.com/AndyLevesque/QuackWorks/tree/main/NeoGrid
• Local clone: /Users/aaron/workspace/infra/neat-little-package/.tmp/QuackWorks/NeoGrid/
• Main files: Neogrid.scad (connectors), DrawerLabelsAndHandles.scad (labels)
• License: CC BY-NC-SA 4.0

System references:

• home-organization/neogrid-reference.md - System overview and material selection
• Fetch QuackWorks repo for current parameter syntax

Core Understanding (Critical Architecture)

What Makes NeoGrid Different: Hybrid Economics

NOT a fully 3D-printed system. NeoGrid separates components by manufacturing efficiency:

3D-print the connectors:

• Junctions (X, T, L, I, End pieces)
• ~50g filament per connector
• Print time: 1-3 hours depending on connector type
• Functional geometry (channels, retention, base mounting)

Buy the dividers:

• 8.5mm uPVC utility board (UK standard)
• 6.35mm (1/4") plywood (US standard)
• 3mm-9mm+ MDF, acrylic, foam board
• Cost: ~$10-20 for entire drawer system vs hundreds in filament
• Faster: Cut to length vs 50+ hours printing sheets

Why this works:

• Connectors require precision geometry (print it)
• Dividers are simple rectangles (buy it cheap)
• Material cost: 90% savings vs fully printed
• Assembly time: Cut dividers once, reuse connectors anywhere

Critical Parameter: Material Thickness

Most important parameter in entire system:

Material_Thickness = 8.5;  // MEASURE YOUR ACTUAL MATERIAL!

Why it's critical:

• Even 0.2mm variation affects friction fit
• Tolerance: ±0.15mm for proper grip
• Too loose: Dividers wobble, layout collapses
• Too tight: Dividers won't insert, connectors crack

Process:

1. Buy material from hardware store
2. Measure with calipers (NOT ruler)
3. If painted: Measure AFTER painting (adds thickness)
4. Print ONE test connector
5. Verify fit before batch printing
6. Adjust parameter by 0.1-0.2mm if needed

Common materials and actual measurements:

Material	Nominal	Actual (measure!)	Setting
UK utility board	8.5mm	8.3-8.7mm	Measure
US 1/4" plywood	6.35mm	6.0-6.5mm	Measure
6mm MDF	6mm	5.8-6.2mm	Measure
3mm acrylic	3mm	2.9-3.1mm	Measure

Base System Integration

Connectors attach to drawer bottom via one of four base types:

Gridfinity (42mm grid):

• Snaps onto Gridfinity baseplate
• Allows repositioning without re-taping
• Grid alignment ensures straight layouts
• Use for drawers with existing Gridfinity setup

OpenGrid (25mm grid):

• Vertical wall mounting option
• Less common for drawer use
• Two variants: Full (6.8mm) or Lite (3.4mm)
• Optional directional snaps for vertical strength

Flat (30mm grid or custom):

• No snap features, just flat base
• Use adhesive/tape to secure
• Flexible grid sizing
• Simple, universal option

None (no base):

• For non-drawer applications
• Dividers rest on surface directly
• Minimal filament usage

Connector Type Navigation

NeoGrid has 6 connector types (plus drawer label holders). Each has dedicated subpage:

Connector	Use case	Read
X Intersection	4-way junctions (interior grid points)	./connector-types/x-intersection.md
T Intersection	3-way junctions (edges, perpendicular joins)	./connector-types/t-intersection.md
L Intersection	Corner junctions (90° turns)	./connector-types/l-intersection.md
I Junction	Straight-through connections (in-line)	./connector-types/straight-through.md
Straight End	Terminators (open ends with buffer)	./connector-types/straight-end.md
Vertical Trim	Edge trim for drawer openings	./connector-types/vertical-trim.md

Drawer labels (bonus accessory):

• Label holders that mount to drawer fronts
• Hook mount (standard) or adhesive tape
• Not part of divider system, but commonly paired
• Read: ./drawer-labels.md

Material Selection Guide

Choose divider material based on budget, availability, and drawer use:

Detailed material comparison: ./hybrid-approach.md

Quick reference:

Material	Thickness	Cost	Pros	Cons
uPVC utility board	8.5mm	Low	Minimal paint, long lengths	UK-specific
Plywood	6mm, 8mm	Low	Strong, natural look	Needs finish
MDF	3mm, 6mm, 8mm	Very low	Cheap, smooth	Heavy, needs retention spikes
Acrylic	3mm, 6mm	Medium	Transparent, clean	Brittle, expensive
Foam board	5mm	Very low	Lightweight	Low strength

Critical reminder: Measure actual material thickness before printing. Nominal ≠ actual.

Base Selection Guide

Choose base system based on drawer setup:

Detailed base options: ./base-options.md

Quick decision framework:

Do you have Gridfinity baseplate in drawer?
├─ Yes → Use Gridfinity base (42mm)
└─ No
   ├─ Want to add Gridfinity later? → Use Gridfinity base (future-proof)
   └─ No Gridfinity needed
      ├─ Want easy repositioning? → Use Flat base + adhesive (30mm)
      └─ Permanent install → Use None (minimal filament)

Multi-tile support (Gridfinity only):

grid_x = 2;  // 2 tiles wide (84mm)
grid_y = 3;  // 3 tiles deep (126mm)

Only X Intersection connectors support multi-tile bases currently.

Connector Selection Framework (Decision Layer)

When User Describes Drawer Layout

Use this decision tree to select connector types:

Ask these questions:

1. How many dividers meet at junction?

   • Four (cross pattern) → X Intersection
   • Three (T pattern) → T Intersection
   • Two (corner) → L Intersection
   • Two (straight line) → I Junction
   • One (end of divider) → Straight End

2. Where is junction located?

   • Interior grid point → X Intersection (most versatile)
   • Edge with perpendicular divider → T Intersection
   • Corner → L Intersection
   • Drawer opening edge → Vertical Trim

3. What's the layout pattern?

   • Regular grid → Mostly X Intersections + edges (T, L, End)
   • Asymmetric compartments → Mix of all types as needed

Example layout analysis:

User: "3×3 grid in my drawer"

Analysis:
- Interior: 4 X Intersections (where grid lines cross)
- Edges: 8 T Intersections (where dividers meet drawer edge)
- Corners: 4 L Intersections (drawer corners)
- Total: 4 X + 8 T + 4 L = 16 connectors + 16 top pieces

Start with X Intersections: Most versatile, works for testing material fit.

Code Generation Best Practices

Parameter Organization

Always declare these parameters at top of file:

// CRITICAL: Material measurement
Material_Thickness = 8.5;      // MEASURE actual material with calipers!
Channel_Depth = 20;            // How deep material sits in connector
Wall_Thickness = 4;            // Connector wall thickness

// Base system selection
Selected_Base = "Gridfinity";  // Gridfinity | openGrid | Flat | None
grid_size = 42;                // Auto-set based on Selected_Base
grid_x = 1;                    // Tiles horizontally (Gridfinity only)
grid_y = 1;                    // Tiles vertically (Gridfinity only)

// Gridfinity-specific
Added_Base_Thickness = 1;      // Extra base height beyond profile

// OpenGrid-specific
openGrid_Full_or_Lite = "Lite";                     // Full | Lite
openGrid_Directional_Snap = false;                   // Vertical mounting
openGrid_Directional_Snap_Orientation = 1;           // 1-4 rotation

// Flat base
Flat_Base_Thickness = 1.4;     // Base thickness in mm

// Material retention
Retention_Spike = false;       // Add spikes for MDF (soft materials)
Spike_Scale = 1;               // Scale spike size

// Part selection
Select_Part = "X Intersection"; // See connector type options
Top_or_Bottom = "Both";        // Top | Bottom | Both

// Top chamfers
Top_Chamfers = true;           // Ease material insertion

Why this order: Critical material parameter first, base system second, optional features last.

Two-Piece System (Base + Top)

All connectors use two-piece design (except Vertical Trim):

// Bottom piece (has base attachment - Gridfinity/openGrid/Flat)
NeoGrid_X_Intersection_Base(
    Material_Thickness,
    Channel_Depth = Channel_Depth,
    Wall_Thickness = Wall_Thickness,
    grid_size = grid_size
);

// Top piece (caps the junction, no base)
NeoGrid_X_Intersection_Top(
    Material_Thickness,
    Channel_Depth = Channel_Depth,
    Wall_Thickness = Wall_Thickness,
    grid_size = grid_size
);

Why two pieces:

• Base provides stability and positioning
• Top locks dividers in place vertically
• Allows swapping divider materials without reprinting bases
• Separate prints = less support material

Assembly: Insert dividers into base channels → Place top piece over junction.

Material Thickness Workflow

When user says "I need connectors for X dividers":

1. Ask about material type and measurement:

   • "What material? (MDF, plywood, acrylic, uPVC)"
   • "Have you measured thickness with calipers?"
   • "If painted, measure after painting"

2. Set Material_Thickness parameter:

   Material_Thickness = 8.5;  // User's measured value
   

3. Recommend test print:

   • "Print ONE X Intersection (base + top) to verify fit"
   • "Divider should friction-fit securely without forcing"
   • "Adjust parameter by ±0.1-0.2mm if needed"

4. Batch printing guidance:

   • "After fit verified, print remaining connectors"
   • "All connectors use same Material_Thickness"
   • "Orientation: Parts print upright as displayed in QuackWorks"

Connector Module Integration

Read the QuackWorks source, don't reinvent:

// DON'T write connector geometry from scratch
// DO fetch current modules from QuackWorks repo

// Option 1: Direct include (if user has BOSL2)
include <BOSL2/std.scad>
include <BOSL2/rounding.scad>
include <path/to/Neogrid.scad>

NeoGrid_X_Intersection_Base(...);

// Option 2: Paste relevant module from QuackWorks
// (if user wants standalone file)
module NeoGrid_X_Intersection_Base(...) {
    // [copied from Neogrid.scad]
}

When to use each connector type: See connector-types/*.md for detailed geometry and use cases.

Common Pitfalls

Pitfall #1: Hardcoding Material Thickness Instead of Measuring

Problem: User says "I have 1/4 inch plywood", code uses Material_Thickness = 6.35, connectors don't fit.

Why it fails: Nominal thickness ≠ actual thickness. 1/4" plywood can be 6.0-6.5mm depending on manufacturer.

Better approach:

// DON'T assume nominal:
Material_Thickness = 6.35;  // "It's 1/4 inch"

// DO ask user to measure:
echo("CRITICAL: Measure actual material with calipers!");
echo("Even 0.2mm variation affects fit.");
Material_Thickness = 6.4;  // User's measured value

Pitfall #2: Skipping Test Print

Problem: User prints 20 connectors, discovers material doesn't fit, wastes filament.

Why it fails: Material variation, printer tolerance, measurement errors compound.

Better approach:

// Workflow guidance:
// 1. Print ONE X Intersection (base + top)
// 2. Test material fit
// 3. Adjust Material_Thickness ±0.1-0.2mm if needed
// 4. THEN batch print remaining connectors

Include in code comments: Remind user to test before batch printing.

Pitfall #3: Wrong Base System for User's Drawer

Problem: User has no Gridfinity baseplate, code generates Gridfinity base, connectors don't sit flat.

Why it fails: Didn't ask about existing drawer setup.

Better approach:

// Ask before generating:
// "Do you have Gridfinity baseplate in this drawer?"
// ├─ Yes → Selected_Base = "Gridfinity"
// └─ No → Selected_Base = "Flat"  // Use adhesive to secure

Pitfall #4: Forgetting Retention Spikes for Soft Materials

Problem: User has MDF dividers, connectors don't grip firmly, layout sags.

Why it fails: MDF is soft, benefits from retention spikes for friction.

Better approach:

// Check material type:
// "What divider material?"
// ├─ MDF → Retention_Spike = true;
// ├─ Plywood → Retention_Spike = false; (optional)
// └─ Acrylic → Retention_Spike = false; (never)

Pitfall #5: Multi-Tile Grid Without Gridfinity Base

Problem: User wants 2×3 connector grid, code sets grid_x=2, grid_y=3 with Selected_Base="Flat", parameters ignored.

Why it fails: Multi-tile support is Gridfinity-only (currently).

Better approach:

// Warn user:
if (grid_x > 1 || grid_y > 1) {
    echo("WARNING: Multi-tile (grid_x/grid_y) only supported with Gridfinity base");
    echo("For Flat/None base, use grid_x=1, grid_y=1");
}

Quality Checklist

Before delivering OpenSCAD code:

Required elements:

• ✓ Material_Thickness parameter clearly documented with measurement reminder
• ✓ Base system selected based on user's drawer setup
• ✓ Appropriate connector type(s) for layout described
• ✓ Top_or_Bottom set correctly (usually "Both")
• ✓ Retention_Spike evaluated based on material type
• ✓ Test print workflow mentioned in comments

Parameter validation:

• ✓ Material_Thickness: User measured actual material (not assumed nominal)
• ✓ Channel_Depth: Default 20mm (adequate for most drawers)
• ✓ Wall_Thickness: Default 4mm (adequate strength)
• ✓ grid_size: Auto-set based on Selected_Base (don't override unless custom)

Base system compliance:

• ✓ Selected_Base matches user's drawer setup
• ✓ If Gridfinity: grid_x/grid_y set for multi-tile (if needed)
• ✓ If openGrid: Full/Lite and directional snap configured
• ✓ If Flat: Flat_Base_Thickness set
• ✓ If None: User understands no base attachment

Code quality:

• ✓ Parameterized (uses Material_Thickness variable, not hardcoded values)
• ✓ Clear variable names
• ✓ Comments explain hybrid system approach
• ✓ Module calls use QuackWorks functions (don't reinvent)
• ✓ BOSL2 library referenced (required dependency)

User communication:

• ✓ Explained hybrid approach (print connectors, buy dividers)
• ✓ Material measurement workflow emphasized
• ✓ Test print recommended before batch
• ✓ Assembly instructions (base → dividers → top)
• ✓ Connector count calculated if layout specified

Assembly Workflow

Standard NeoGrid assembly process:

1. Design layout: Measure drawer, plan divider pattern
2. Measure material: Use calipers on actual divider material
3. Test print: ONE connector type (X Intersection recommended)
4. Verify fit: Material should friction-fit with slight resistance
5. Adjust if needed: ±0.1-0.2mm on Material_Thickness parameter
6. Cut dividers: Standard length 160mm (or 42mm × N - Material_Thickness)
7. Batch print: All connectors for layout
8. Assemble: Place bases → insert dividers → add tops
9. Install: Place in drawer (on baseplate or with adhesive)

Documentation References

NeoGrid Ecosystem:

• NeoGrid 2.0: Hybrid drawer organization system
• Created by Hands on Katie (Katie)
• Licensed CC BY-NC-SA 4.0
• This skill focuses on CODE GENERATION for connectors

Related skills:

• home-organization/neogrid-reference.md - System overview, material selection, use cases
• For system selection guidance, defer to that skill
• This skill is only for "generate OpenSCAD code for NeoGrid connectors"

Official resources:

• https://handsonkatie.com/neogrid-organise-your-big-items-with-this-free-and-open-source-system/
• https://github.com/AndyLevesque/QuackWorks/tree/main/NeoGrid (authoritative code)
• https://makerworld.com/en/models/1501061-neogrid-2-0-drawer-management-system