Extend AeroAlign with mixed CoG planning and telemetry base

hardware/cad/README.md

@@ -1,14 +1,19 @@
 # SkyLogic AeroAlign - 3D Printable Parts
 
-**Status**: Placeholder documentation for Phase 1 design
-**Design Tool**: FreeCAD 0.20+ (open-source parametric CAD)
-**Export Format**: STL for 3D printing
+**Status**: active documentation for AeroAlign plus planned CoG fixtures  
+**Design Tool**: FreeCAD 0.20+  
+**Export Format**: STL
 
 ---
 
 ## Overview
 
-This directory will contain all 3D printable parts for the SkyLogic AeroAlign wireless RC telemetry system. Parts are designed to fit within 200mm × 200mm × 200mm build volume (compatible with Ender 3, Prusa Mini, Bambu Lab P1P).
+This directory covers both halves of the project:
+
+- AeroAlign IMU housings and clips
+- future CoG scale fixtures and support cradles
+
+All parts should stay printable on common 200mm-class FDM printers.
 
 ---
 
@@ -47,7 +52,7 @@ This directory will contain all 3D printable parts for the SkyLogic AeroAlign wi
    - For 8mm thick control surfaces (large rudders, thicker wings)
    - Reinforced jaw design
 
-### Multi-Sensor Expansion (Phase 8)
+### Multi-Sensor Expansion / Future AeroAlign
 
 6. **wing_surface_mount_adjustable.stl**
    - 3-point contact clip for wing root attachment
@@ -76,6 +81,24 @@ This directory will contain all 3D printable parts for the SkyLogic AeroAlign wi
     - Variant of sensor_housing_top.stl with magnet pockets
     - 2× N52 neodymium magnets (10mm diameter × 2mm thick)
 
+### CoG Scale Fixtures (Planned)
+
+12. **cog_baseplate.stl**
+    - Flat base aligning front and rear supports
+    - Carries the support spacing reference
+
+13. **cog_support_front.stl**
+    - Front cradle above load cell #1
+    - Should include anti-slip contact pad area
+
+14. **cog_support_rear.stl**
+    - Rear cradle above load cell #2
+    - Matching geometry for repeatable support spacing
+
+15. **cog_hx711_mount.stl**
+    - Protected electronics bracket for HX711 boards
+    - Cable strain relief recommended
+
 ---
 
 ## Print Settings
@@ -155,13 +178,15 @@ This directory will contain all 3D printable parts for the SkyLogic AeroAlign wi
 
 ## Testing and Validation
 
-### Phase 2 Validation Tasks
+### Validation Tasks
 
 - [ ] T058: Print sensor housing on Ender 3 (verify fit and tolerance)
 - [ ] T059: Test print on Prusa Mini and Bambu Lab P1P (cross-printer compatibility)
 - [ ] T060: Create assembly guide with photos
 - [ ] T061: Document print settings for all STL files
 - [ ] T062: Weigh assembled nodes (verify <25g per node)
+- [ ] Validate CoG support rigidity under expected aircraft weights
+- [ ] Validate repeatable support spacing for CoG calculation
 
 ### Durability Testing
 
@@ -219,9 +244,9 @@ Under the following terms:
 
 ## Roadmap
 
-**Phase 1 (Current)**: Design sensor housing and basic clips
-**Phase 2**: Validate print quality on 3 printer brands
-**Phase 8**: Design specialized mounts for 8-sensor expansion
+**Current**: IMU housing and clips  
+**Next**: CoG baseplate and load-cell support fixtures  
+**Later**: integrated mixed-tool workshop kit
 
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