Stable, adjustable support
I compared direct and belt drives, single- and dual-roller drive, and fixed versus symmetric adjustment. The selected layout drives both rollers and keeps the workpiece centered laterally as the spacing changes.
MECHANICAL ENGINEERING · UC DAVIS ’28
Sakura
Chiwata.
I design mechanisms and bring them to life.
Mechanical design, mechatronics, and hands-on testing—from the first CAD model to a working machine.
B.S. Mechanical Engineering
University of California, Davis · June 2028
Watch the working prototype ↗
01 / FEATURED PROJECT
One machine.
A full surface view.
A dual-roller inspection system that rotates cylindrical products beneath a line-scan camera, turning their outer surface into a continuous image.
As a mechatronics engineering intern, I developed the mechanical design, selected components, assembled the system, and integrated the PLC, servo, camera, and bilingual web interface with guidance from my supervisor.
11 → 1Belt sizes required
30+Captures with no dropped frames
15.6–107.5 mmTested workpiece diameters
Original design requirements: Ø10–100 mm · up to 300 mm long · up to 7 kg. Tested diameter range shown above.
SEE IT WORK
From command
to capture.
Under 4 seconds from start command to image capture.
In this tested setup, capture completed less than 4 seconds after pressing Start. The 21-second demonstration was intentionally paced more slowly to show the workflow; rotation time is adjustable for faster operation.
- 01
Configure the capture
The web interface calculates motion and imaging parameters and sends them to the PLC.
- 02
Rotate the workpiece
A servo and belt transmission drive both support rollers beneath the line-scan camera.
- 03
View the surface image
The captured lines form an unwrapped view of the cylindrical surface.
THE MECHANICAL CHALLENGE
Eleven belts.
One better mechanism.
Changing the roller spacing also changes the belt path. The initial design called for 11 size-specific timing belts, requiring a belt change between workpiece ranges.
I developed the tensioner geometry, travel, spring load, and component layout. An adjustable, spring-loaded idler takes up the changing belt path, allowing one belt to serve the full operating range.
- Spring
- Pulls the idler carriage to maintain belt tension.
- Sliding idler
- Moves along the guide as the required belt path changes.
- Shared belt
- Drives both rollers while accommodating adjustable spacing.
DESIGN → MANUFACTURE → INTEGRATE
Engineering behind
the hardware.
I compared drive architectures, checked the components against the operating requirements, and prepared the system for fabrication and assembly.
Calculations before parts
I used torque and inertia calculations for servo selection, shaft-deflection and fit calculations for the roller supports, and belt-tension calculations for the transmission.
From CAD to assembly
I modeled the assembly in Fusion 360, checked interference, and produced manufacturing drawings, BOMs, and supplier-ready specifications.
Explore the CAD and control interface
CONTROLS & VALIDATION
Making motion and
imaging work together.
A working mechanism was only part of the problem. The camera and workpiece motion also had to agree.
I tuned the servo response and adjusted the camera start timing to avoid startup distortion. The bilingual interface calculates parameters from diameter, resolution, and rotation time, enabling one-click acquisition.
Time to reach commanded speed
Reduced through servo auto-tuning.
Required camera start delay
Intentional delay before acquisition to avoid startup distortion.
THE OUTPUT
A curved surface,
unwrapped.
The larger test workpiece and its captured surface image.
This is the actual line-scan output, including the packaging texture, printed labels, and reflections. The system completed 30+ captures with no dropped frames.
02 / OTHER WORK
Full résumé ↗More ways to build.
Rear Cargo Integration
Redesigned cargo-floor brackets and mounting arrangements for packaging, support, and enclosure accessibility. Used bending-stress calculations and Siemens NX static FEA for a 180 lb distributed load.
Enclosure access: 90 → 64 seconds in team testing.
Motion-Tracking Cooling Fan
Built a servo-driven platform for a camera-based tracking fan and refined printed components for alignment, fit, wiring, and airflow. My focus was the mechanical hardware and testing.
Cooling pads: 15°F lower test-surface temperature versus no pads. Noise: 56 → 32 dB after shroud and vibration modifications.
Snack Vending Machine
Designed a servo-driven helical-coil dispenser with an ESP32. Iterated on servo angles, coil placement, and product clearances.
45+ jam-free test cycles.
LET’S CONNECT
Sakura Chiwata
Mechanical engineering student at UC Davis.
Interested in mechanical design, mechatronics, and product development.