Apparatus, systems and methods for use in three-dimensional printing

A three-dimensional printing machine comprising:

• rails mounted to the three-dimensional printing machine;
• bearing assemblies which ride on the rails, the bearing assemblies on at least one of the rails being configured to deform laterally in response to expansion or contraction of components of the three-dimensional printing machine;
• a carriage movably mounted on the bearing assemblies to controllably move in the direction of a slow axis with respect to the three-dimensional printing machine;
• and
• a printhead coupled to the carriage to controllably move in the direction of the fast axis with respect to the carriage and the three-dimensional printer.

A three-dimensional printing machine comprising:

• a carriage mounted on the three-dimensional printing machine to controllably move in the direction of a slow axis with respect to the three-dimensional printing machine;
• and
• a printhead coupled to the carriage to controllably move in the direction of a fast axis with respect to the carriage and the three-dimensional printer;
• and
• an air bearing coupled to the printhead wherein the air bearing is slidably mounted to the carriage to move along the carriage with low friction.