About this 3D model

Little hearts chained, place, back, in all the senses, like the links of a chain. https://www.youtube.com/watch?v=KmZPL5JP47o&feature=youtu.be I preferred to make three pieces apart. therefore, print two cores and a link nut. Mount the three pieces for a little. There are small notches to immobilize the hearts. A + NOP21