About this 3D model

Did you already have fun with the duplo marble run (http://www.thingiverse.com/thing:159219)? Then you are ready for much more fun and challenge! Extend your marble run with a marble pump inspired by the great work of Matthias Wandel (http://woodgears.ca/marbles/lifter.html). Push up marbles using the lever. (No motor.) The drop-block mechanism prevents the marbles from falling back. Please read the instructions. OpenSCAD files are included. See marble pump in action: http://youtu.be/2z1Rwl-ASx4 http://youtu.be/mFvod_YRR_w