I saw a picture of marble machine years ago and I finally got around to trying to make my own. As expected, it was a challenge to get mechanism worked out. I had to remake the cup and adjust the pivot point but I eventually got it working as shown in video. I made mine from wood but I've included all the STL files in case you are up to trying to print your own. You will need to supply your own 9/16" Marbles. You can purchase similar versions from Amazon: http://amzn.to/2ClyTrw Build Instructions for this one:https://www.instructables.com/id/Wooden-Marble-Roller-Machine/