Miniature Ten Pin Bowling

My nephew wanted to make a miniature ten pin bowling game and found a suitable piece of wooden skirting board and a ball bearing to use as the ball. We grabbed a bowling pin from the Google 3D Warehouse (http://sketchup.google.com/3dwarehouse/details?mid=d6b915030d74878f4fa86d12e3299e2d) and converted it from SketchUp to STL online using babel3d.com before sending it to cloud.netfabb.com to clean up the model. We designed a ramp for the ball in OpenSCAD to make the game more challenging than j