Great Ball Contraption(GBC) and Japan Brickfest(JBF) 2017 Fan Weekend.June 10-11, 2017 Rokko Island Kobe

23 GBC modules are built by four persons. 250 balls are used.
Akiyuki (13 modules)
Takanori Hashimoto (the yattara) (3 modules)
Katsumata (5 modules)
Y. Kuramata (2 modules)