Sparkleball friend Carl Boro has astonished me again. He built this full blue sparkleball — blue cups and blue lights– with blue bobby pins! Carl discovered that long bobby pins are perfect for connecting the 9 oz hard plastic cups. (Not Solo-style soft cups. They have a raised lip.) I did a quick google search and found Durahome, EDI, and Party Essential hard cups on Amazon. My local grocery sometimes has them, and so does Party City. If you build one, make sure you check out the Hard Cup instruction page. The Hard Cup formula is different than the Original Sparkleball.
Carl says you’ll need about 126 bobby pins. Not a big investment. He also said that the clips slipped a little when he put the lights in, but once that was done, he just straightened the ball out.