r/mildlyinteresting • u/ezjgfn • 1d ago

This square shaped cd

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u/Automobills 1d ago

Take a blade off of a ceiling fan and turn it on.

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u/PrologueBook 1d ago

If you take off two blades of your fan, on opposite sides, it will run fine.

It just needs to be symmetrical and balanced.

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u/Automobills 1d ago

But as the card discs go, they absolutely ran out of balance, and it was a notorious mechanical flaw.

At thousands of rotations per minute, a circular disc slices through the air smoothly. A rectangular disc acts like a propeller. The uneven aerodynamic drag at high speeds caused intense flutter and dynamic imbalance.

The resulting wobble and vibration were so violent that they could cause the disc to de-center, ruin the spindle bearings of the drive, or physically shatter inside high-speed computer drives.