Day 5: (Wed Sep 10, Week 3) Motion Transmission, Gears and Linkages

Notes for 2025-09-10.

Assignments

Due Mon Sep 15: Exercise: Music Box. Please have the device in hand for class on Sep 15. Please submit documentation to Assignment 2 Shared Folder.

Administrative

The first FriDeATe (social free food) event will be Friday, Sep 12 5-6PM in the basement open area.

Agenda

1. Mechanical transmission discussion

   • shafts

   • clevis structures

   • linkages

   • gears

   • belts

   • limit stops

2. Design examples

   • four-bar linkage

   • mechanical-puppet (linkages)

   • gears (Design Example: Gears)

   • piano action

   • laptop stand (joinery)

   • knee (thin-section bearings)

3. Sound production

   • wood on wood percussion

   • metal on metal percussion

   • strings

   • membranes

   • resonance

   • tuning forks (music box comb, https://en.wikipedia.org/wiki/Tuning_fork)

   • wind instruments (harp, whirly tube)

   • for very general inspiration: Hornbostel-Sachs musical instrument classification

4. Quick design review for the music box assignment.

Video

Cristofori action - Escapement action for earliest fortepiano by Bartolomeo Cristofori, 1726

Aeolian Harp With Three-Gallon Bottle Resonator

What Do Whirly Tubes Sound Like?

Sounds of a Glass Armonica