Patent ID: 9656427
Date: 2017-05-23
CPC Classifications: B29C,B33Y

Claim:
1. A system comprising: a three-dimensional printer including an extruder, a build chamber including a build region where a build is to be initiated, an x-y-z positioning assembly operable to move the extruder within the build chamber, and a controller configured to cooperate with the extruder and the x-y-z positioning assembly to fabricate a three-dimensional object on a build platform within the build chamber; a heater configured to heat the build chamber, the heater including at least two separate and independently controllable heating elements; a blower positionable to move air over the heater and toward the build region at a first flow rate before fabrication of the three-dimensional object is initiated for preheating the build region to a predetermined build region temperature and, after preheating the build region to the predetermined build region temperature, to increase a flow rate of air over the heater to a second flow rate for maintaining a target temperature for the build chamber after fabrication of the three-dimensional object is initiated, wherein the second flow rate more vigorously mixes air throughout the build chamber relative to the first flow rate; a power source configured to supply power to the heater; and a controller configured to provide pulse-width modulation (PWM) control of the heating elements in a manner that staggers an on-cycle among the heating elements to reduce a peak load demand on the power source.