Comment by zokier

FreeCAD is the big name, but I'd check out SolveSpace too. Then there is of course OpenSCAD which works well for the things it happens to work well for, but I wouldn't call it full replacement for a CAD. To wrap up there is the oldie and honestly bit intimidating BRL-CAD, which I'm kinda trying to learn whenever I feel like I need to do mechanical design.