Lego Great Ball Contraption (GBC) - 17 modulestracking the blue and red balls.running at 1.0 balls/sec500 ballssize : 1.5m×6.5mpath length : 31mconstruction time : 600 hoursmy blog http://legokarakuri.blog91.fc2.com/1. ball factory (inspired by superbird28)2. zigzag stair3. zigzag lift4. pneumatic (sometimes spilling balls)5. cup6. screw T17. basket shooter8. mechanical train (lack of reliability)9. screw T210. screw T311. spiral lift T212. elevator & coaster (coaster inspired by Hidaka's ball rolling)13. fork14. spiral lift T1 & step15. catch & release16. belt conveyor & pinball17. 5-axis robot S750