Add clarifying comments about duplicate parts and calculation method

Co-authored-by: dorkmo <[email protected]>

Author: Copilot

LifeTrac-v25/mechanical_design/openscad/CNCLAYOUT_CHANGES.md

@@ -0,0 +1,123 @@
+# CNC Layout Changes
+
+## Overview
+The `cnclayout.scad` file has been refactored to arrange parts in a left-to-right layout optimized for direct CNC machine use.
+
+## Changes Made
+
+### 1. Layout Arrangement: Left-to-Right
+**Previous**: Parts were arranged in multiple rows (top to bottom)
+**New**: All parts are arranged in a single horizontal line from left to right
+
+This makes it easier for CNC operators to:
+- Follow the cutting sequence
+- Understand the material flow
+- Optimize sheet placement
+
+### 2. Text Labels Removed
+**Previous**: Each part had text labels for identification
+**New**: All text elements have been removed
+
+Benefits:
+- Output is ready for direct import into CNC software
+- No manual cleanup needed
+- Prevents text from interfering with cutting paths
+- Cleaner DXF/SVG exports
+
+### 3. Parametric Spacing
+**Previous**: Some spacing was hard-coded
+**New**: All spacing is calculated parametrically based on part dimensions
+
+The layout now:
+- Defines dimensions for each part type
+- Calculates X positions based on actual part widths
+- Uses the `SPACING` parameter (20mm) consistently between all parts
+- Automatically adjusts if part dimensions change in the future
+
+### 4. No Overlapping Parts
+Each part's position is calculated by adding:
+- Previous part's X position
+- Previous part's width
+- Spacing constant (20mm)
+
+This ensures no parts overlap, even if dimensions are changed in the parameter file.
+
+## Part Order (Left to Right)
+
+1. Side Panels (4x) - Largest parts, rotated 90°
+2. Rear Crossmember
+3. Bucket Bottom
+4. Standing Deck
+5. Bucket Sides (2x) - Rotated 90°
+6. Wheel Mounts (4x)
+7. Cylinder Lugs (6x)
+
+Total: 19 parts in a single horizontal line
+
+## Layout Dimensions
+
+- **Total Width**: ~9.9 meters
+- **Total Height**: ~1.4 meters
+- **Spacing**: 20mm between all parts
+- **Start Position**: (10, 10)
+
+## Usage
+
+### Generate SVG for CNC
+```bash
+cd LifeTrac-v25/mechanical_design/openscad
+openscad --export-format=svg -o output/cnclayout.svg cnclayout.scad
+```
+
+### Generate DXF for CNC
+```bash
+openscad --export-format=dxf -o output/cnclayout.dxf cnclayout.scad
+```
+
+### Adjust Spacing
+To change the spacing between parts, edit the `SPACING` parameter in `cnclayout.scad`:
+```openscad
+SPACING = 20; // mm between parts - change this value as needed
+```
+
+## Technical Details
+
+### Parametric Dimensions
+All part dimensions are derived from the main parameter file (`lifetrac_v25_params.scad`):
+- `MACHINE_HEIGHT` - Used for side panel dimensions
+- `WHEEL_BASE` - Used for side panel dimensions
+- `BUCKET_WIDTH`, `BUCKET_DEPTH` - Used for bucket parts
+- `DECK_WIDTH`, `DECK_DEPTH` - Used for standing deck
+- etc.
+
+### Position Calculation
+Positions are calculated sequentially:
+```openscad
+x_pos_0 = START_X;
+x_pos_1 = x_pos_0 + side_panel_width_rotated + SPACING;
+x_pos_2 = x_pos_1 + side_panel_width_rotated + SPACING;
+// ... and so on
+```
+
+This approach ensures:
+- No variable reassignment (OpenSCAD compatible)
+- Clear dependency chain
+- Easy to understand and modify
+- Automatic adjustment when dimensions change
+
+## Compatibility
+
+The layout is compatible with:
+- OpenSCAD 2019.05 and later
+- CNC plasma cutters
+- Laser cutters
+- Waterjet cutters
+- Any CNC software that accepts SVG or DXF input
+
+## Future Enhancements
+
+Possible future improvements:
+- Add optional material optimization (nesting)
+- Support for multiple sheet layouts
+- Automatic part labeling layer (toggle-able)
+- Kerf compensation parameters

LifeTrac-v25/mechanical_design/openscad/cnclayout.scad

@@ -69,6 +69,8 @@ bucket_side_height_rotated = BUCKET_DEPTH;  // 600mm (becomes height when rotate
 // =============================================================================
 // CALCULATE X POSITIONS (parametric, left-to-right)
 // =============================================================================
+// Note: OpenSCAD requires all variables to be defined at once (no reassignment)
+// This sequential calculation ensures proper spacing and no overlaps
 
 // X positions calculated sequentially
 x_pos_0 = START_X;
@@ -95,19 +97,20 @@ x_pos_18 = x_pos_17 + cylinder_lug_width + SPACING;
 // LAYOUT ALL PARTS (LEFT TO RIGHT)
 // =============================================================================
 
-// Part 0: Side panel outer (rotated 90°)
+// Part 0: Side panel outer - Left side (rotated 90°)
 layout_part(x_pos_0, START_Y, 90)
 side_panel(is_inner=false);
 
-// Part 1: Side panel inner (rotated 90°)
+// Part 1: Side panel inner - Left side (rotated 90°)
 layout_part(x_pos_1, START_Y, 90)
 side_panel(is_inner=true);
 
-// Part 2: Side panel inner (duplicate) (rotated 90°)
+// Part 2: Side panel inner - Right side (rotated 90°)
+// Note: Four panels total create a sandwich design with arms between inner pair
 layout_part(x_pos_2, START_Y, 90)
 side_panel(is_inner=true);
 
-// Part 3: Side panel outer (duplicate) (rotated 90°)
+// Part 3: Side panel outer - Right side (rotated 90°)
 layout_part(x_pos_3, START_Y, 90)
 side_panel(is_inner=false);
 
@@ -123,11 +126,11 @@ bucket_bottom();
 layout_part(x_pos_6, START_Y, 0)
 standing_deck();
 
-// Part 7: Bucket side (rotated 90°)
+// Part 7: Bucket side - Left (rotated 90°)
 layout_part(x_pos_7, START_Y, 90)
 bucket_side();
 
-// Part 8: Bucket side (duplicate, rotated 90°)
+// Part 8: Bucket side - Right (rotated 90°)
 layout_part(x_pos_8, START_Y, 90)
 bucket_side();