neogrid-openscad

What this skill does

# 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
- **Main files**: `Neogrid.scad` (connectors), `DrawerLabelsAndHandles.scad` (labels)
- **License**: CC BY-NC-SA 4.0

**System references:**

- For system overview and material selection, see the home-organization skill
- 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:

```openscad
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):**

```openscad
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:

```openscad
// 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 = "Gr