Downloadable three-dimensional models

A system comprising:

• a database storing a plurality of different machine-ready models of an object, each one of the plurality of different machine-ready models based on a three-dimensional model of the object and adapted for fabricating the object on one of a number of different types of three-dimensional printers each having a predetermined configuration resulting in different slicing rules for converting the three-dimensional model into a corresponding one of the machine-ready models;
• and
• a server coupled to the database and coupled in a communicating relationship with a data network, the server configured to respond to a request from a client for the object through the data network by identifying a type of three-dimensional printer locally associated with the client making the request,
• selecting one of the machine-ready models from among the plurality of different machine-ready models of the object,
• wherein the one of the machine-ready models is selected as corresponding to the type of three-dimensional printer locally associated with the client, and
• transmitting the one of the machine-ready models to the client through the data network,
• wherein the server is further configured to manage a print queue for the three-dimensional printer locally associated with the client and at least one additional three-dimensional printer, and
• to automatically determine when a request to fabricate a selected one of the machine-ready models should be redirected to the at least one additional three-dimensional printer.