Extrusion Catcher
thingiverse
This extrusion catcher version features a tab for attaching it to the bottom left corner bolt of the build platform. Watch it in action here: http://www.youtube.com/watch?v=8P1vekuYYgo. For assembly, drill a larger hole in the tab's pilot hole and trim the wedge support part to ensure the bolt head sits flat against it. As for the gcode script, try experimenting with it in ReplicatorG before executing on your bot to guarantee its success during printing. Start by moving the head over the extrusion catcher then back to the platform's origin.
With this file you will be able to print Extrusion Catcher with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Extrusion Catcher.