Projects / Strain-Gauge Beam Lab
Strain-Gauge Beam Lab
Build a keepable cantilever beam lab from laser-cut 3mm birch plywood: clamp a birch beam at its root, hang known masses at the tip, measure the deflection, and get Young’s modulus of birch from the slope (E = F·L³/3Iδ). An optional bar load cell + HX711 checks the force side.
$9 Physics
Digital guide + cut files + BOM + code · Parts sourced separately · Ages 8–14 with adult help
ActuationHX711 + bar cell
Structure3mm birch cantilever
ControllerArduino Uno/Nano
Build time3–5 hours
Skill levelIntermediate
Ages8+
Pack contents
- Build guide: root clamp, deflection gauge, E from the slope; optional HX711 force check
- SVG cut files for beam, root clamp, base, mass hanger
- First principles: stress, strain, σ = Eε, cantilever deflection
- Optional HX711 Arduino sketch with tare + known-mass calibration
- Verified BOM (~$11–38 hardware for the deflection lab; $29–82 with the optional load-cell check)
Typical hardware cost
Default structure is laser-cut birch plywood with real fasteners and hobby electronics—honest BOM, not mystery modules.
- ~$11–38 for the deflection lab ($29–82 with the optional load-cell check) in typical parts
- Digital pack price ≠ hardware
The $9 pack is the digital guide + cut files + BOM + lessons + code, plus printable Builder's Corner build journal pages. Hardware sourced separately — see Where to get kit materials.
Questions? Email us at lance.haney@gmail.com.
Pricing
- Home / Personal license $9
- Classroom license $35 — 1 teacher, up to 30 studentsOne $35 Classroom license covers one group of up to 30 students. Each additional group needs another license.
- Build materials available at cost + 10% — email for a quote
Learning outcomes
- Clamp a birch cantilever and measure tip deflection under known loads
- Compute I = bh³/12 and E = FL³/(3Iδ) from the force–deflection slope
- Explain Young’s modulus as the slope of the stress–strain line
- Report uncertainty from off-axis loading and creep