saltylab-firmware/BOM_GOPRO_MOUNT.md

# GoPro Mount Adapter - Bill of Materials
## Issue #195

### 3D Printed Components

| Part | Qty | Material | Weight | Notes |
|------|-----|----------|--------|-------|
| GoPro Mount Base | 1 | PLA/PETG | ~8g | Top interface, receives GoPro 3-prong connector |
| Tilt Arm Assembly | 1 | PLA/PETG | ~12g | Connects GoPro mount to T-slot clamp, rotates on pivot |
| Pivot Housing | 1 | PLA/PETG | ~10g | Mounts to T-slot clamp, houses pivot pin |
| T-Slot Clamp Base | 1 | PLA/PETG | ~6g | Fixed base mounting to sensor rail |

**Subtotal Printed:** ~36g

### Hardware Components

| Part | Qty | Size | Material | Source | Notes |
|------|-----|------|----------|--------|-------|
| Pivot Pin (Bolt) | 1 | M8 x 40mm | Steel | Hardware Store | Central pivot for tilt mechanism |
| Pivot Pin (Nut) | 1 | M8 | Steel | Hardware Store | Secures pivot pin |
| Thumbscrew | 1 | M5 x 8mm | Steel with Knob | Hardware Store | Locks tilt position (standard M5 thumb knob) |
| Detent Spring Ball | 1 | 4mm stainless | Stainless Steel | Ball bearing supplier | Springs into detent pockets (0°, 15°, 30°, 45°, 60°, 75°, 90°) |
| Compression Spring | 1 | M4 x 15mm | Steel | Hardware Store | Pushes detent ball into pockets (spring constant ~3-4 N/mm) |
| T-Nut | 1 | M4 x 20mm | Aluminum | T-slot Supplier | For T-slot rail mounting |
| M4 Bolt | 4 | 8-10mm length | Steel | Hardware Store | Mounting bolts for T-nut (4-point pattern) |
| Washer | 4 | M4 | Stainless Steel | Hardware Store | Under bolt heads to distribute load |
| Hex Nut | 1 | M8 | Steel | Hardware Store | Secures pivot pin (if needed for adjustment) |

### Assembly Materials

| Item | Qty | Type | Purpose | Notes |
|------|-----|------|---------|-------|
| Thread-lock (Loctite) | 1 small tube | Medium strength (blue) | Lock thumbscrew position | Prevents vibration loosening |
| Grease (PTFE-based) | 1 small tube | Silicone or PTFE | Lubricate pivot joint | For smooth tilt operation |
| Sandpaper | 1 set | P400/P600 grit | Post-print finishing | Sand all moving surfaces smooth |

### Print Settings

| Parameter | Recommended |
|-----------|-------------|
| Material | PLA or PETG |
| Nozzle Temperature | 200-210°C (PLA) / 230-245°C (PETG) |
| Bed Temperature | 60°C (PLA) / 80-90°C (PETG) |
| Layer Height | 0.2mm (standard) or 0.1mm (fine) |
| Infill | 20-25% (higher for pivot areas due to stress) |
| Supports | Yes - required for GoPro mount underside and pivot pockets |
| Print Time | ~4-5 hours |
| Estimated Weight | 36g printed (matches sub-50g target if optimized) |

### Assembly Checklist

- [ ] Print all 4 components with supports
- [ ] Remove supports and sand surfaces
- [ ] Sand pivot surfaces smooth (P600) for frictionless rotation
- [ ] Clean all parts with compressed air
- [ ] Install M8 pivot pin through housing and arm
- [ ] Install M8 nut and washer on pivot pin (hand-tight + 1/2 turn)
- [ ] Apply PTFE grease to pivot joint
- [ ] Install 4mm detent ball in spring
- [ ] Insert spring + ball assembly into detent housing
- [ ] Install compression spring and M4 bolt for spring retention
- [ ] Test tilt mechanism: should click into 7 detent positions
- [ ] Install T-nut and M4 mounting bolts to T-slot rail
- [ ] Install M5 thumbscrew for tilt locking
- [ ] Apply thread-lock to thumbscrew (if needed)
- [ ] Test GoPro mount: insert standard GoPro 3-prong connector
- [ ] Verify all tilt detents hold firmly
- [ ] Test thumbscrew locking at various angles

### Sourcing Notes

#### Where to Buy

**3D Printing Service (if not printing yourself):**
- Prusa Printing (prusa3d.com)
- Shapeways (shapeways.com)
- OnShape + local printer
- ~$15-25 for all parts in PLA

**Hardware (Local Options):**
- Home Depot / Lowes: T-nuts, bolts, washers, springs
- Ace Hardware: Thumbscrew knobs, grease
- Amazon: Bulk hardware kits, ball bearings
- McMaster-Carr: Premium hardware, precision springs

**Specialty (Online):**
- SDP/SI (sdp-si.com): Precision balls, springs
- VXB Bearings: Ball bearings and precision components
- Misumi: Aluminum hardware

### Cost Breakdown

| Category | Cost | Notes |
|----------|------|-------|
| 3D Printing | $2-5 | If self-printing; $15-25 if outsourced |
| Hardware | $8-12 | Pivot pin, bolts, springs, thumbscrew |
| Assembly Materials | $3-5 | Grease, sandpaper, thread-lock |
| **Total** | **$13-22** | Budget-friendly sensor integration |

### Weight Analysis

| Component | Weight |
|-----------|--------|
| Printed parts | 36g |
| M8 bolt + nut | 8g |
| M5 thumbscrew | 3g |
| Springs + ball | 2g |
| T-nut + M4 bolts | 6g |
| **Total** | **~55g** |

**Note:** Can optimize to <50g by:
- Reducing infill to 15% in non-stress areas
- Using aluminum M8 bolt instead of steel
- Using nylon M4 bolts instead of steel

### Quality Assurance

#### Testing Points

1. **Pivot Smoothness:** No grinding or binding, smooth rotation
2. **Detent Engagement:** Audible/tactile click at each 15° position
3. **Tilt Lock:** Thumbscrew holds position against moderate force (~5 kg applied force)
4. **GoPro Interface:** Standard GoPro mount seats fully and securely
5. **T-slot Mounting:** Rock-solid attachment, no wobble
6. **Repeated Use:** 100+ tilt cycles without wear

### Maintenance

- **Monthly:** Check thumbscrew tightness, verify detents still click
- **As Needed:** Reapply PTFE grease to pivot if rotation becomes rough
- **If Detents Wear:** Replace 4mm ball or detent pocket (reprint arm if needed)
- **If Pivot Loosens:** Retighten M8 nut with 2mm clearance (should not be too tight)

### Compatibility Notes

**GoPro Models Supported:**
- GoPro Hero 11/12 (with standard 3-prong mount)
- GoPro Hero 9/10 (with standard 3-prong mount)
- GoPro Hero 8 (with standard 3-prong mount)
- Any device with standard GoPro 3-prong interface

**Not Compatible:**
- GoPro Hero 7 or older (different mounting system)
- Devices without GoPro 3-prong connector

**Adapter Options:**
- Can add GoPro-to-other-mount adapters on top for non-GoPro cameras
- Design allows stacking of standard GoPro accessories

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**Bill of Materials Version:** 1.0
**Design Status:** Complete
**Last Updated:** 2026-03-02
**Issue:** #195