Knobs that feel honest

A control is a contract with the hand. The knob promises a range, a center, a click, or a smooth sweep. When the hardware and the software disagree, people stop trusting the panel and start poking randomly.

Match travel to meaning

Fine adjustments need more degrees of rotation than coarse ones. Mapping a 270° pot to a binary mode switch is theatrical. Mapping a tiny trimmer to volume is cruel.

Detents are grammar

Use detents for discrete states. Use smooth travel for continuous ones. Mixing them because the part was in the drawer creates a dialect nobody asked to learn.

Enclosure is interface

If the knob wobbles in the panel, the user feels cheapness before they feel the feature. Support the shaft, align the bushing, and leave finger clearance that does not require a jeweler's posture.