# Bill of Materials

## Hardware Required for One HandUMI (Single Unit)

Hardware needed to build one HandUMI unit. Prices use the unit cost from the
linked listing, multiplied by the quantity needed.

### Mechanical & Structural

| Part | Qty Needed | Unit Price | Link | Total (USD)* |
|---|---|---|---|---:|
| PLA Filament (only ~200 g needed per unit) | 0.2 kg | $12.59 / kg | [Amazon](https://www.amazon.com/ELEGOO-Filament-Dimensional-Accuracy-Cardboard/dp/B0BM739JRF) | $2.52 |
| Rolling Bearing | 4 | $13.29 / 20 pcs | [Amazon](https://www.amazon.com/uxcell-3mmx6mmx2-5mm-Shielded-Miniature-Bearing/dp/B075CMRGY6) | $2.66 |
| Linear Bearing | 4 | $7.49 / 4 pcs | [Amazon](https://www.amazon.com/uxcell-LM6UU-Linear-Bearings-Length/dp/B07H95CWTX) | $7.49 |
| Axle (135 mm) | 1 rod | $11.99 / 10 pcs | [Amazon](https://www.amazon.com/dp/B08Z8JGZZC) | $1.20 |
| M3 Hardware Kit (750 pcs) | 5 total (1 @ M3x20mm + 2 @ M3x12mm + 2 @ M3x15mm*) | $9.99 / 750 pcs | [Amazon](https://www.amazon.com/Fgruh-750PCS-Assortment-Washers-Assorted/dp/B0RJV3FCBN) | $0.07 |
| Velcro Tape | 50 cm | $15.78 / 500 cm | [Amazon](https://www.amazon.sg/Self-Adhesive-Velcro-Metres-Black-Fleece/dp/B08FBC7H5K) | $1.58 |
| M2 Hardware Kit (660 pcs) | 16 total (8 screws + 8 nuts) | $7.99 / 660 pcs | [Amazon](https://www.amazon.com/WZHUIDA-Screws-Assortment-M2x4mm-Washers/dp/B0F93XL3WK) | $0.19 |
| **Subtotal** | | | | **$15.70** |

### Electronics

| Part | Qty Needed | Unit Price | Link | Total (USD)* |
|---|---|---|---|---:|
| Fisheye USB Camera | 1 | $56.99 | [Amazon](https://www.amazon.com/Arducam-Computer-Fisheye-Microphone-Windows/dp/B07ZS75KZR) | $56.99 |
| Feetech Servomotor | 1 | $13.89 | [Alibaba](https://www.alibaba.com/product-detail/Top-Seller-Low-Cost-Feetech-STS3215_1600999461525.html) | $13.89 |
| Power Supply | 1 | $10.00 | [Amazon](https://www.amazon.com/Facmogu-Switching-Transformer-Compatible-5-5x2-1mm/dp/B087LY41PV) | $10.00 |
| Feetech Servo Controller | 1 | $10.60 | [Amazon](https://www.amazon.com/Waveshare-Integrates-Control-Circuit-Supports/dp/B0CTMM4LWK) | $10.60 |
| USB-C Cable | 1 | $7.00 / 2 pcs | [Amazon](https://www.amazon.com/Charging-etguuds-Charger-Braided-Compatible/dp/B0B8NWLLW2) | $3.50 |
| **Subtotal** | | | | **$94.98** |

### Total

| | |
|---|---:|
| **GRAND TOTAL (approx.)** | **$110.68** |
| If building a pair (2 units) | $221.37 |

\*Unit Price reflects the real per-unit cost from the linked listing (e.g. pack
price ÷ pack quantity); Total = Unit Price × Qty Needed. Prices are early
reference estimates and may vary with shipping, region, and availability.

**Note:** this BOM does not include the VR headset (e.g. PICO 4 Ultra /
Meta Quest) used for the shared tracking layer. That is a separate, one-time
purchase, not duplicated per HandUMI unit.