Another to check out is Solvespace. It's a much smaller simpler CAD modeling program than FreeCAD; doesn't do nearly as much, but I find it much easier to use,

Another to check out is Solvespace. It's a much smaller simpler CAD modeling program than FreeCAD; doesn't do nearly as much, but I find it much easier to use, more intuitive, and more stable than FreeCAD.