A planning BOM for the low-cost prototype. Every price below is an estimate from approximate small-quantity online prices; none is a purchase record. The table is generated from materials/bom.csv, so a changed line changes every cost figure in the documentation at once.
| Item | Qty | Unit | Unit price | Price basis | Purchased price | Source date | Reused | Notes | |—|—|—|—|—|—|—|—|—| | ESP32 DevKit V1 | 2 | each | $6 | estimate | not recorded | not recorded | unknown | Rocket flight computer and launcher | | MPU6050 IMU module | 1 | each | $4 | estimate | not recorded | not recorded | unknown | Rocket roll sensing | | SG90-class micro servo | 5 | each | $3 | estimate | not recorded | not recorded | unknown | Four canards plus ignition servo; firmware drives six servos in total (D-021) | | QMC5883L compass | 1 | each | $4 | estimate | not recorded | not recorded | unknown | Launcher heading estimate | | BMP180 barometer | 1 | each | $3 | estimate | not recorded | not recorded | unknown | Launcher altitude/environment estimate | | GPS receiver module | 1 | each | $10 | estimate | not recorded | not recorded | unknown | Launcher location/status | | Switches, button, LED, buzzer | 1 | set | $5 | estimate | not recorded | not recorded | unknown | Physical launch interlock and indicators | | Battery/regulator/wiring | 1 | set | $12 | estimate | not recorded | not recorded | unknown | Depends on available lab stock | | FDM filament | 1 | spool share | $8 | estimate | not recorded | not recorded | unknown | Airframe/launcher printed parts | | Fasteners, inserts, adhesives | 1 | set | $8 | estimate | not recorded | not recorded | unknown | Mechanical assembly |
Subtotal of estimates: $81 across 10 lines. 10 lines are estimates; 0 purchased prices are recorded. Shipping, spares, and tax are excluded. Source: materials/bom.csv.
| Field | Meaning |
|---|---|
price_basis |
estimate, purchased, reused, or unknown |
purchased_price_usd |
Blank means not recorded, not free |
source_date |
Blank means not recorded; estimates age |
reused |
yes, no, or unknown; reused parts have no purchase cost but are not free to replace |
Shipping, spares, tax, and tools are excluded. Known mismatch: the firmware drives six servos (five on the rocket, one on the launcher) and the folding-rocket CAD references an MG996R, while the BOM lists five SG90-class servos (D-021). Reconcile against an as-built inventory before citing a cost.
| Upgrade | Why it matters | Trade-off |
|---|---|---|
| Higher-torque servos | More control authority under aerodynamic load | Higher current draw and mass |
| Dedicated power regulation | Reduces brownout risk during servo motion | More wiring and cost |
| Better IMU | Lower drift and better vibration tolerance | More expensive and new driver work |
| Logging storage on rocket | Captures data if RF link drops | Adds mass and failure modes |
| Custom PCB | Cleaner wiring and repeatability | Higher design and fabrication effort |