For the Take Your Child To Work Day this year myself and a friend decided that we would do a marble run for the children. Rather than ordering tracks and pieces to assemble the marble run with, we decided to create/print our own tracks. We created them in a way that the children could use Legos to hold the tracks up. We also created a slanted Lego piece to assist in angling the tracks.
http://3ddash.blogspot.com/2017/04/marble-run.html
Great idea! 
