Skip to content
storagebits
← Projects

Spindl

A 3.5-inch, 7,200 rpm hard drive taken apart in the browser: spin-up, head load, a seek drawn live, the rotational wait, the 3 nm flying height, the emergency park. Every gauge reads the model that moves the parts.

CI passing · public
Inside a hard drive seen from above: the arm holds its head over an inner track lit in orange, and the target sector, a short orange mark, comes round toward it.

A desktop hard drive, the kind with two platters and four heads, rebuilt from code and set in motion. One input drives everything, the drive’s own time: the platters turn at 120 revolutions a second, the arm swings on its voice coil, and the panels read the same numbers that pose the parts.

  • Seven subsystems to open: the spindle motor in section, the platter stack exploded with its four heads on one cylinder, the voice coil with its top magnet lifted, a camera down to the slider and its air bearing, the parking ramp, the servo wedges, the electronics.
  • Real figures, checked: 15 m/s under the head at the inner edge and 35 m/s at the outer one, 0.9 ms track to track, 8.5 ms over a third of the stroke, 250 MB/s outside and 120 MB/s inside across 16 recording zones. A script recomputes each one.
  • Slow motion down to 1/8000: a seek lasts 14 ms and a revolution 8.33 ms; slowed down, the speed profile is drawn live and the target sector comes round under the head.
  • Pull the plug: cut the power and watch the heads return to the ramp on the energy of the slowing spindle.

Left alone, the page plays a guided tour. In English, French and Spanish. Built with Claude Code and the teardown skill.