Projects / Stepper Clock Escapement
Stepper Clock Escapement
Build a keepable desk clock trainer from laser-cut 3mm birch plywood: clock face, minute hand, and a 28BYJ-48 stepper on a ULN2003 driver. Learn step angles, gearing, and open-loop timing.
$12 Mechatronics
Digital guide + cut files + BOM + code · Parts sourced separately · Ages 8–14 with adult help
Actuation28BYJ-48 + ULN2003
Structure3mm birch clock face
ControllerArduino Uno/Nano
Build time4–6 hours
Skill levelIntermediate
Ages8+
Pack contents
- Build guide: face, hands, stepper mount, ULN2003 wiring
- SVG cut files for face (motor mounts directly), hands, stand with tab-and-slot base
- First principles: step angle, gear ratio, open-loop timing error
- Arduino sketch: 1 RPM-class minute-hand drive + catch-up test
- Verified BOM (~$22–77 hardware)
Typical hardware cost
Default structure is laser-cut birch plywood with real fasteners and hobby electronics—honest BOM, not mystery modules.
- ~$22–77 in typical parts
- Digital pack price ≠ hardware
The $12 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 $12
- Classroom license $45 — 1 teacher, up to 30 studentsOne $45 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
- Drive a 28BYJ-48 through ULN2003 without overloading Arduino pins
- Map steps-per-revolution to a one-minute hand sweep
- Explain open-loop timing drift and how gearing multiplies error
- The real 28BYJ-48 gear ratio (63.684:1) and why "2048" runs 7 min/day fast; hour hand is manual set