Camera Gantry

I needed a way of holding a camera in a stable position for desktop photographing of various small items. A desktop tripod was not really working for me, so I designed this gantry (a bit derived from a traveling crane!)
The camera can be held at a wide variety of orientations and heights, and then easily locked in place by tightening the knobs at either end. The whole thing collapses down flat to go in a cupboard.
The non-plastic parts are four 12mm by 400mmm aluminium tubes, with caps on to a