as with most kits on shapeways the tolerances vary from print to print, you'll need to tighten the joints with floor polish or superglue to get the tightness just right. (even then with all ball joints they do get loose over time or extended play). Have you painted it yet? The paint will give it a slight increase in thickness as well. As for your request, unfortunately I've stopped doing 3D print designs until I have more free time to spare.