Apple AirPort Time Capsule - Tolerances

I spent a better part of my day replacing the hard drive on my AirPort Time Capsule (model A1470).

This thing is a wonderous piece of technology. Where the design of every cubic inch (or cubic millimeter) has tight tolerances.

So tight that I learned that hard drive makers have slight variances in their models.

Seagate makes the original hard drive in the Time Capsule. I built my own computers and only consider:

• dimensions, in this case: 3.5”
• interface, in this case: SATA
• capacity, in this case: 2TB

Each drive manufacturer must conform to these and more. Even the position of the mounting holes must exist in the same spot on any drive.

After going through the iFixIt article - I learned the original hard drive is smaller than a standard one.. To make another drive fit. one would have to trim the rubber segments.

Wow - who would have thought there would be such differences? At the same time, every single AirPort Time Capsule uses the same rubber segments.

This tight tolerance in the AirPort Time Capsule places a strict requirement on the hard drive manufacturer. Changing hard drive dimensions in any aspect would require changing rubber segments.

If such tight tolerances are not observed:

• the product would be less beautiful to accommodate for supplier variances
• OR manufacturing would accommodate for variances by having exponential number of designs

Companies can accommodate one or the other or both!

In this case, it seems Apple does not accommodate to either - which increases tolerance.