Interesting paper, but the structure they refer to in there, if I understood it correctly, is actually a support column not the moving gantry itself. While the paper starts off talking about the gantry all the study work is on the column design. So the jury is still out on whether a lightweight CF gantry beam is better. However, the information is useful as regards the gantry supports. The issue however, is for the small sizes we generally build, i.e. a gantry side 300 - 500mm high or so, does the complexity of forming such a structure give any benefit over a slab of 20mm ali?