Openscad is a neat tool, I have used it plenty because I prefer code over a GUI. It tends to slow down for large complicated scenes. Depending on what exactly

Openscad is a neat tool, I have used it plenty because I prefer code over a GUI. It tends to slow down for large complicated scenes. Depending on what exactly you have in mind, you might want the ability to show both "assembled" and "printing" layouts of your pieces. I have done something like this in openscad, it was manual and clunky, but it worked. If you want to do start with some smallish, blocky puzzles, openscad is not a bad tool to start with.