There oughta be a Lego marble run

My son loves marble runs, but as he became more interested in Lego than the bigger Duplo bricks, I needed a marble run for Lego. So I printed one. This is a rather simple project, but I stumbled onto an interesting physics detail that I wanted to discuss. Click the image to see the video on youtube.com. Most of you probably just want to watch the video, but if you want to dive into the physics…