Puzzle Conversion
grabcad
Example of a conversion from STL to STEP/DXF. See the original author and files here: https://www.reddit.com/r/AutodeskInventor/comments/r14cg1/help_converting_stl_mesh_to_solid_for_use_in/The application used for converting these was InStep Studio 3D (https://instepstudio3d.com/)
Download Model from grabcad
With this file you will be able to print Puzzle Conversion with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Puzzle Conversion.