This is a smaller - and faster - version of http://www.thingiverse.com/thing:1618843 and http://www.thingiverse.com/thing:1653916
The earlier version 'ticked' once a second, this version ticks twice a second.
This version is designed to be made on machines with a build volume of at least130x130x120 (WxDxH)
I plan one more version designed for a build volume of at least120x120x100.
Designed in Moment of Inspiraton (Moi).
Made in PLA mostly on an Ultimaker Original plus some parts made on a CEL Robox and on a Flux3DP.
A video of the finished article is here: https://youtu.be/A4zOAPIbeP0
Generally speaking 1.2mm walls.
Also generally I used a brim.
Also used CEL Robox and Flux3DP
Holes sized with hand reamers.
It is absolutely critical that all moving parts move very freely.
The pendulum bob and the hanging weight contain lead fishing sinkers.
The weight of the bob and the hanging weight that work for me are (including the bottles) 43gm for the bob and 417gm for the hanging weight.
By the way the frame extensions can be stacked so you can print more and make a taller tower which will tick for longer.
Based on photos of a metal model of the Galileo pendulum. Designed in Moment of Inspiration and simulated in SimLab Composer.