References and files
Literature
| Reference | Used for | Notes |
|---|---|---|
| NASA LaRC Strain Gage Balance Design Concepts (NTRS 19990072772) - link | design rules: one piece, ~1-1.5 mV/V, measuring sections, gauging, calibration | notes |
| Ulbrich & Bader, Analysis of Sting Balance Calibration Data Using Optimized Regression Models (NTRS 20100024136) - link | two-moment calibration, term selection (PRESS, VIF) | notes |
| Moore, Recommended Strain Gage Application Procedures for LaRC Balances (NTRS 19970020057) - link | gauge installation, checks, adhesives | notes 1, notes 2 |
| Loving & Luoma, NASA TN D-4021 Sting-Support Interference (1967) - link | sting/pod ratio, straight sting length, base pressure, tare method | notes |
| External Six-Component Strain Gauge Balance for Low Speed Wind Tunnels (Scientific Technical Review, 2014) | alternative architecture, accuracy benchmark | notes |
| Design and Fabrication of a 3-Component Internal Strain Gauge Balance (student report) | cross-check of neck sizing; mistakes to avoid | notes |
| Barlow, Rae & Pope, Low-Speed Wind Tunnel Testing | wall corrections, balance practice | book |
| Covert (ed.), Thrust and Drag: Its Prediction and Verification (AIAA) | drag accounting, calibration and uncertainty background | book |
Combined findings: 00_SYNTHESIS.md.
Files in this package
CAD (STEP, millimetres; coordinates x aft of the BMC)
"envelope" files are simplified shapes of purchased parts for clearance checks only. Groups marked "superseded" belong to earlier designs and are kept for reference only.
Drawings
WT_drawing_set.pdf (36 sheets) and individual sheets on the Drawings page.
Analysis and CAD scripts (Python)
| File | Purpose |
|---|---|
| six_component_balance_sizing.py | neck and flexure sizing, outputs, stresses, deflections |
| motion_envelope.py | kinematics (α, β from machine angles and inverse), wall-clearance envelope, interlock |
| motion_system_sizing.py | drive torques, bearing and wheel loads, motor speeds, steps per degree (updated 2026-10-03 to the as-designed drives) |
| balance_calibration_fit.py | 3-component calibration fit (superseded by the 6-component version; its regression helpers are reused) |
| calibration_schedule_aluminum.csv | bench load schedule (3-component) |
| balance_calibration_fit_6c.py, calibration_schedule_6c.csv | 6-component calibration: schedule (233 rows), fit, inversion, synthetic demo |
| build_6c_balance_cad.py, build_roll_spindle_cad.py, pod_instrumentation.py, build_calibration_stand_cad.py | parametric CadQuery models (reference copies; they import sibling modules from the original project layout) |
| build_pitch_sector_cad.py, build_yaw_carriage_cad.py, build_calibration_6c_cad.py | pitch sector, yaw carriage and 6-component calibration CAD with interference sweeps |
| calibration_6c_mass_properties.json | weights and CGs of the calibration hardware (input to the fit) |
| machining_cost_estimate.py, .csv, jlccnc_quote_2026-10-03.json | machining cost model (calibrated to the JLCCNC quote) and the quote itself |
| collect_quote_step_files.py | builds the quote package (STEP files + parts manifest) for machining suppliers |
| make_electronics_diagrams.py | generates the electronics wiring diagrams |
| gdt_sheet.py | drawing engine used for the GD&T sheets |
The analysis scripts need Python 3 with numpy; the CAD scripts need CadQuery.