I gave FreeCAD a test drive, and built this model in the process.
FreeCAD seems to be in the midst of a major overhaul. In their forums, the developers discuss this excellent presentation from the makers of Solid Edge, and have taken it to heart. Once they digest the very sound advice on making robust CAD models, and roll out the new release, FreeCAD will be worth another look. They are an active and enthusiastic community, and could use more manpower to achieve their goals. However, since my current goal is to create models, I'm going to look elsewhere for now, and give FreeCAD some time to mature.
Update: Go try Onshape!