Over-the-Top Marble Machine

This little marble machine uses 6mm Airsoft BB's for the balls. When they get to the bottom, just tap the little thwacker and send them back over the top to the start. It's actually a little more challenging than it looks! See how many balls you can keep going at the same time.Plus, it prints in one piece (except for the feet) and with no supports!Watch it go: Print SettingsPrinter:UDIORafts: NoSupports:NoResolution: 0.2mmInfill:15% Notes: Print OTTMM.STL plus four of the OTMM_foot.STL. The feet should press into the divots in the bottom of the marble machine, but if they are loose, secure them with a drop of superglue.After printing, you need to run some fine sandpaper or steel wool through the track to make it very smooth - the slighted bump will cause the balls to hang up. Keep at it until the balls run the entire length of the track without hesitation.Post-PrintingPlaying with this is a little trickier than is seems, due to the lively action of the thwacker.Operating the thwacker t