Don't let software impede your creativity. Adopt TopSolid for your design and pre-sizing activities
The integrated CAD solution: 3D/PDM design, kinetic, static, dynamic (link to MATLAB), strength of materials, rheology (Cadmould), drawings and parts lists, technical manuals and assembly/dismantling videos.
TopSolid guides and helps you by taking the design intention into consideration, while leaving you enough freedom to make decisions in view of the design rules and standards.
Example: each component brings its own environment, a shim piece makes its own groove, a screw makes its own hole in the first part and, therefore, a threaded hole in the second part. The length is determined automatically according to the diameter and the thickness of the parts to be assembled.