Shape binder is highly versatile tool that helps in multibody modeling. This tutorial explain the shape binder usage. This is a key concept in modeling where you maintain relationship between bodies.... You need to master this if you are to build complex models See my prior Videos where I use Shapebinder in Freecad Cell Phone Case Modeling in FreeCad. https://youtu.be/oDrMME9-iS4 How to Model Twisted Spiral Vase https://youtu.be/LIJWXFBEQbY