I wanted to have a look at OpenSCAD so I redsigned http://www.thingiverse.com/thing:8198 to be parametric.You can choose the width of the belt, the number of open sides, the width of the bars, the size of the middle piece and the size of the openings as parameters.See http://miniaturegiantspacehamster.blogspot.com/ for details on the original design.enter the dimensions of the buckle you need, export as 2D graphic (e.g. DXF) or 3D file (e.g. STL)