
Getting the Calculations Right for a Perfectly-Balanced Mobile
As I discuss in Chapter 6, you can create a mobile in SketchUp and design it in the software so that - when 3D printed or otherwise fabricated - this mobile hangs perfectly in the balance. This process works for all planar designs, independent of how many levels such a mobile may have.
Example mobile with highlighted free-body diagram levels
Step 1: Break the mobile down into individual Free-Body Diagrams (FBDs)
The previous image shows one of my recent students' mobiles. It has a great theme and while it doesn't push this method enough (it is very symmetrical), it helps me explain this step.
From a structural perspective, you need to break down the entire mobile into its sub-structures and their respective free-body diagrams (FBDs). You basically need to separate each of its individual levels in this step. The image shows how this looks for my student's mobile.
Once broken down this way, you would analyze this mobile from the bottom to the top, following...