The best free CAD alternative to Autodesk Maya is K-3D, which is also Open Source. If that doesn't work for you, our users have ranked more than 50 alternatives to Autodesk Maya, but unfortunately only two of them are free CAD Software. If you can't find an alternative you can try to remove all filters.
K-3D is free-as-in-freedom 3D modeling and animation software. It features a plugin-oriented procedural engine for all of its content, making K-3D a very versatile and powerful package.
Gmsh is a 3D finite element grid generator with a build-in CAD engine and post-processor. Its design goal is to provide a fast, light and user-friendly meshing tool with parametric input and advanced visualization capabilities.
Gmsh is for modeling, not animation.