Double Pendulum

Every physics department needs a double pendulum, so here's how I built ours. The big improvement is that the bottom pendulum can be locked in place. This turns the chaotic double pendulum into a non-chaotic physical pendulum.

This project was originally published 31.Aug.2007 on as part of their Science Fair contest.


I'm going to be lazy and skip writing a big long introduction or explanation for this and just focus on how mine is put together. The links below are good starting points for background info. (Simulation) (a neat version made from two square plates).

Top Pendulum Assembly

Top_Pendulum_Assembly_1.jpg Top_Pendulum_Assembly_2.jpg Top_Pendulum_Assembly_3.jpg Top_Pendulum_Assembly_4.jpg

Top_Pendulum_Assembly_5.jpg Top_Pendulum_Assembly_6.jpg Top_Pendulum_Assembly_7.jpg Top_Pendulum_Assembly_8.jpg Top_Pendulum_Assembly_9.jpg

Bottom Pendulum Assembly

Bottom_Pendulum_Assembly_1.jpg Bottom_Pendulum_Assembly_2.jpg Bottom_Pendulum_Assembly_3.jpg Bottom_Pendulum_Assembly_4.jpg

Bottom_Pendulum_Assembly_5.jpg Bottom_Pendulum_Assembly_6.jpg Bottom_Pendulum_Assembly_7.jpg Bottom_Pendulum_Assembly_8.jpg Bottom_Pendulum_Assembly_9.jpg

Complete Double Pendulum Assembly

Complete_Double_Pendulum_1.jpg Complete_Double_Pendulum_2.jpg Complete_Double_Pendulum_3.jpg

Complete_Double_Pendulum_4.jpg Complete_Double_Pendulum_5.jpg Complete_Double_Pendulum_6.jpg Complete_Double_Pendulum_7.jpg

CAD Files

Download an AutoCAD .DWG or a .ZIP file of parts from Alibre Design Xpress.


Please send any questions or comments to me at

Go back to my home page.

Go to the Lecture Demonstration webpage.

This page was first uploaded on 31.August.2007 and last updated on 24.August.2010.