Blockscad

BlocksCAD is a cloud-based, block-based 3D modeling software that is built on OpenSCAD. Users not only learn programming skills but learn about the underlying geometry of the 3D space, and about basic CAD fundamentals without having to create work arounds. The software is easy enough to be used by third graders, but powerful enough to be used productively by adults. while providing rich learning outcomes by developing strong math and computer programming skills. With a simple block-based programming interface, students will write programs to design their models.
Tutorials:
BlocksCAD YouTube playlist
BlocksCAD Documentation
Design Your Own Fidget Toy Using BlocksCAD
BlocksCAD 101 - Making 3D Models with Code Blocks
BlocksCAD 102: Coding a 3D Box That Grows
BlocksCAD 103: Making the fitted Box Top
BlocksCAD 104: 3D Modeling a Multi-compartment Box with Code
Chris Wallace's Beginning 3D design


Challenge:
Design a fidget spinner where:
Your bearings have an exterior diameter of 22mm
Your bearings have an interial diameter of 4mm
Your marbles have a diameter of 14.95mm