Add folding operator platform with parametric design

Replaces the fixed standing deck with a 5-component folding platform system, including new parametric OpenSCAD modules for the deck plate, pivot brackets, and angle iron arms. Updates the BOM, CNC layout, and all relevant assemblies to support the folding platform, adds export files for CNC cutting, and integrates pivot and lock pin holes into the frame and side panels. Legacy standing deck files are deprecated and redirected for backward compatibility.

Author: dorkmo

LifeTrac-v25/mechanical_design/documentation/BILL_OF_MATERIALS.md

@@ -15,11 +15,17 @@
 
 **Total Square Tubing:** ~10 meters (33 feet)
 
-### Angle Iron (Optional - for reinforcement)
+### Angle Iron
 
 | Size | Thickness | Length | Quantity | Purpose |
 |------|-----------|--------|----------|---------|
-| 3" × 3" | 1/4" | As needed | Variable | Frame gussets and reinforcement |
+| 2" × 2" | 1/4" (6.35mm) | 350mm (14") | 2 | Folding platform arms | F2 |
+| 3" × 3" | 1/4" | As needed | Variable | Frame gussets and reinforcement (optional) |
+
+**Note:** Platform angle iron arms require drilling per template in `platform_angle_arm.scad`:
+- 3× bolt holes (1/2" + 2mm clearance) at each end
+- Hole spacing: 30mm apart, centered on leg
+- See [PLATFORM_ANGLE_ARM](../openscad/parts/platform_angle_arm.scad) for drilling template
 
 ---
 
@@ -33,7 +39,8 @@
 | Bucket back | 1100mm × 400mm | 1 | Bucket | E1 |
 | Bucket sides | 600mm × 400mm | 2 | Bucket | E1 |
 | Loader arm reinforcement | 150mm × 1200mm | 2 | Arm structure | C1 |
-| Standing deck | 1000mm × 400mm | 1 | Operator platform | F1 |
+| Platform deck | 850mm × 400mm | 1 | Folding operator platform | F1 |
+| Platform pivot brackets | 150mm × 100mm | 2 | Platform hinge mount | F3 |
 | Control housing base | 300mm × 200mm | 1 | Electronics mount | G1 |
 
 **Total 1/4" Plate:** Approximately 8-9 m² (86-97 sq ft)
@@ -129,6 +136,15 @@
 | 1/2" diameter | 2"-6" | 100 | Plate mounting, general assembly |
 | 1/4" diameter | 1"-3" | 50 | Light-duty mounting |
 
+### Pivot Pins and Lock Pins
+
+| Size | Length | Quantity | Purpose | Part Ref |
+|------|--------|----------|---------|----------|
+| 1" (25.4mm) round bar | 50mm (2") | 2 | Folding platform pivot pins | F4 |
+| 3/8" (9.5mm) cotter pins | Standard | 4 | Platform lock pins (deployed + stowed) | F5 |
+
+**Note:** Pivot pins should be machined with a groove or hole for cotter pin retention.
+
 ### Hex Nuts (Grade 8)
 
 | Size | Approximate Qty |

LifeTrac-v25/mechanical_design/openscad/cnclayout.scad

@@ -13,7 +13,8 @@ use <parts/side_panel.scad>
 use <parts/rear_crossmember.scad>
 use <parts/wheel_mount.scad>
 use <parts/cylinder_lug.scad>
-use <parts/standing_deck.scad>
+use <parts/platform_deck.scad>
+use <parts/platform_pivot_bracket.scad>
 use <parts/bucket_bottom.scad>
 use <parts/bucket_side.scad>
 
@@ -58,9 +59,13 @@ cylinder_lug_height = 150;
 bucket_bottom_width = BUCKET_WIDTH;   // 1100mm
 bucket_bottom_height = BUCKET_DEPTH;  // 600mm
 
-// Standing deck dimensions
-standing_deck_width = DECK_WIDTH;   // 700mm
-standing_deck_height = DECK_DEPTH;  // 400mm
+// Platform deck dimensions (replaces standing_deck)
+platform_deck_width = PLATFORM_WIDTH;     // ~850mm (parametric from inner wall spacing)
+platform_deck_height = PLATFORM_DEPTH;    // 400mm
+
+// Platform pivot bracket dimensions (2 required)
+pivot_bracket_width = PLATFORM_BRACKET_LENGTH;   // 150mm
+pivot_bracket_height = PLATFORM_BRACKET_WIDTH;   // 100mm
 
 // Bucket side dimensions (rotated 90 degrees in layout)
 bucket_side_width_rotated = BUCKET_HEIGHT; // 450mm (becomes width when rotated)
@@ -79,9 +84,11 @@ x_pos_2 = x_pos_1 + side_panel_width_rotated + SPACING;
 x_pos_3 = x_pos_2 + side_panel_width_rotated + SPACING;
 x_pos_4 = x_pos_3 + side_panel_width_rotated + SPACING;
 x_pos_5 = x_pos_4 + crossmember_width + SPACING;
-x_pos_6 = x_pos_5 + bucket_bottom_width + SPACING;
-x_pos_7 = x_pos_6 + standing_deck_width + SPACING;
-x_pos_8 = x_pos_7 + bucket_side_width_rotated + SPACING;
+x_pos_6 = x_pos_5 + bucket_bottom_width + SPACING;        // Platform deck
+x_pos_7 = x_pos_6 + platform_deck_width + SPACING;         // Pivot bracket 1
+x_pos_7b = x_pos_7 + pivot_bracket_width + SPACING;        // Pivot bracket 2
+x_pos_8_base = x_pos_7b + pivot_bracket_width + SPACING;   // Bucket sides start
+x_pos_8 = x_pos_8_base + bucket_side_width_rotated + SPACING;
 x_pos_9 = x_pos_8 + bucket_side_width_rotated + SPACING;
 x_pos_10 = x_pos_9 + wheel_mount_size + SPACING;
 x_pos_11 = x_pos_10 + wheel_mount_size + SPACING;
@@ -125,12 +132,20 @@ rear_crossmember();
 layout_part(x_pos_5, START_Y, 0)
 bucket_bottom();
 
-// Part 6: Standing deck
+// Part 6: Platform deck (replaces standing_deck)
 layout_part(x_pos_6, START_Y, 0)
-standing_deck();
+platform_deck();
+
+// Part 7: Platform pivot bracket - Left
+layout_part(x_pos_7, START_Y, 0)
+platform_pivot_bracket();
+
+// Part 7b: Platform pivot bracket - Right
+layout_part(x_pos_7b, START_Y, 0)
+platform_pivot_bracket();
 
-// Part 7: Bucket side - Left (rotated 90°)
-layout_part(x_pos_7, START_Y, 90)
+// Part 8: Bucket side - Left (rotated 90°)
+layout_part(x_pos_8_base, START_Y, 90)
 bucket_side();
 
 // Part 8: Bucket side - Right (rotated 90°)