Initial infrastructure documentation - comprehensive homelab reference

Printing/Key caps/CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is an OpenSCAD project for scaling 3D-printed mechanical keyboard keycaps while preserving the Cherry MX stem dimensions. The project contains scripts to reduce keycap body dimensions for better socket fit while maintaining the exact 4mm × 4mm stem cross dimensions required for Cherry MX switches.
+
+## Key Commands
+
+### Rendering STL Files
+
+On Windows, OpenSCAD is typically installed at `C:\Program Files\OpenSCAD\openscad.exe`. Use Git Bash path format:
+
+```bash
+# Render a SCAD file to STL
+"/c/Program Files/OpenSCAD/openscad.exe" -o "output.stl" "input.scad"
+
+# Clear cache and render (recommended when changing imports)
+"/c/Program Files/OpenSCAD/openscad.exe" --clear-cache -o "output.stl" "input.scad"
+```
+
+### Verify OpenSCAD Installation
+
+```bash
+# Check if OpenSCAD is installed
+if exist "C:\Program Files\OpenSCAD\openscad.exe" echo Found at C:\Program Files\OpenSCAD\openscad.exe
+```
+
+## Project Architecture
+
+### Main Scripts
+
+- **`Body5_scaled_FIXED.scad`**: The primary working script that uses a centered-import approach. This is the recommended version for scaling keycaps.
+- **`Body5_scaled.scad`**: Earlier version that manually positions the stem preservation cylinder using explicit X/Y coordinates.
+- **`Body5_test_circle.scad`**: Test script with exaggerated parameters (larger cylinder) to verify the circular stem preservation is working.
+- **`test_cylinder.scad`**: Simple cylinder rendering test for OpenSCAD verification.
+
+### STL Files
+
+- **`Body5.stl`**: The original keycap model that gets imported and processed by the SCAD scripts.
+- **`Body2.stl`**: Alternative keycap model.
+- **Generated STL files**: Output from rendering the SCAD scripts (e.g., `Body5_scaled_98percent.stl`).
+
+### Scaling Algorithm
+
+The scripts use a two-part union approach:
+
+1. **Scaled Body with Cutout**: The entire keycap is scaled down by `body_scale_xy`, then a cylinder is subtracted where the stem should be
+2. **Unscaled Stem Region**: A cylinder intersection preserves the original stem region at 100% scale
+3. **Union**: Both parts are merged, creating a keycap with scaled body but original stem dimensions
+
+The `_FIXED` version centers the model at the origin before operations, making cylinder placement simpler. The non-FIXED version requires manual positioning of the preservation cylinder using `stem_x` and `stem_y` coordinates.
+
+### Critical Parameters
+
+- **`body_scale_xy`**: X/Y scaling factor (typically 0.97-0.99 for 1-3% reduction)
+- **`body_scale_z`**: Z scaling factor (keep at 1.00 to maintain keycap height)
+- **`stem_diameter`**: Diameter of circular preservation region (default: 5.5mm)
+- **`stem_height`**: Height of stem region (default: 8.0mm)
+- **`$fn`**: OpenSCAD circle resolution (64-128, higher = smoother but slower)
+
+### Centering Approach (FIXED version)
+
+The `centered_import()` module translates the imported STL by `[-209, -223.5, -4.9]` to center it at the origin. These values were determined by analyzing the original STL's bounding box. This allows stem operations to use simple `cylinder()` calls at the origin rather than calculating offsets.
+
+## Development Workflow
+
+1. Modify SCAD script parameters (typically just `body_scale_xy`)
+2. Render to STL using OpenSCAD command line or GUI (F5 preview, F6 full render in GUI)
+3. Import STL into slicer and print test keycap
+4. Measure fit and iterate on scaling factor
+5. Typical iteration: start at 0.98, adjust by 0.01 increments based on fit testing
+
+## Important Notes
+
+- The Cherry MX stem cross is exactly 4mm × 4mm by specification and must not be scaled
+- The circular preservation region accommodates off-brand switches that may have slightly different tolerances
+- All SCAD scripts expect `Body5.stl` (or specified STL file) to be in the same directory
+- Rendering is computationally intensive due to importing the STL twice (once for scaling, once for stem preservation)