Spindle is a relationship focused 3d data visualization model, consisting of 3 parts: a common axis, several classes and the number axis of each class. This project visualize the relationship between the publish years and check out counts of all loaner items related to the seven deadly sins in Seattle Public Library by presenting each item as a straight line. Each line is connected to the common axis (time axis),
by their publish years, and to the number axis by the item's class and the check out count. Different colors are used to distinguish the classes. Also, the thickness and the location of the endpoint of the line are decided the item’s check out count. User can interact with the model by changing which year to be shown on central panel, picking a specific item to stand it out or applying filters of classes to clarify the visual presentation.