BB-dan is Japanese brand name of ball bullets for toy guns. The bullets are plastic spheres with a diameter of 6mm, and are very cheap, for example 4, 000 bullets costs you about 1, 000 yen (equivalent to approximately 8 US dollars). Ball crystal models called some times “marble ball models” are constructed by using these tiny ball bullets. Here I give the name BB-dan model, because the bullet is called BB-dan. The constructing methods are detailed. The pictures of models for a hexagonal compact structure, a body centered cubic structure, a zinc-blende type structure and a Si(111) 7×7 reconstructed structure are given.