## Getting the Calculations Correct 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. In this post, I'll show you how to run the calculations for the mobile so that its equilibrium is assured. Example mobile with highlighted free-body diagram levels Tutorial Steps 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 nicely. 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 four sketched outlines...

## Placing Wind Turbines with my Random Tools Extension

In this tutorial I use the example of a large wind turbine array to show how useful my Random Tools extension for SketchUp can be in making things look more realistic - by rotating turbine blades in this case. Tutorial Video https://www.youtube.com/watch?v=aHuqTEaOtI0 Tutorial Steps Time needed: 10 minutes. The three main steps to prepare a component for use with SketchUp's Random Tools extension are also illustrated below. For this example it is best to use a component, not a group. As I show in the video, grouping the rotor blades will not allow the extension to properly place its center at the rotation axis. Therefore, start by selecting the rotor blades and the axle and using the "Make Component" tool. In the Make Component tool, we then need to place its axis at the center of rotation. Click the "Set Component Axis" button and then place the axis as shown below. Now you can use the "Randomize Objects" tool from the Random Tools...