Based on Reprap Pen Holder: http://www.thingiverse.com/thing:31983 i updated the OpenSCAD (attached) to fit the penholder on my battery holder: http://www.thingiverse.com/thing:109807 In this way the Micro-Hexapod: http://www.thingiverse.com/thing:5156 (by ljon) http://www.thingiverse.com/thing:34796 (remixed by carlosgs) becomes a drawbot :) PenHolder_hexapoduino_front is for the front support of the battery holder; PenHolder_hexapoduino_back is for the back support of the battery holder. In this way you can use 2 pens at the same time! The OpenSCAD file, available for download, is parametric. You can find here a full description of the project: http://www.instructables.com/id/Hexapoduino-tiny-hexapod-3D-printed-Arduino-cont/