A hot end associated with an extruder for a Fused Filament Fabrication (FFF) three dimensional (3D) printer includes, in at least one aspect of the subject matter described in this specification: a heater; a temperature sensor coupled with the heater; an FFF material delivery channel; a heat sink coupled with the FFF material delivery channel; a nozzle coupled with the FFF material delivery channel and with the heater, the nozzle having a total included angle of less than or equal to sixty degrees and greater than or equal to ten degrees, with respect to a nozzle target point; and a cooling delivery system for at least the heat sink; where the heat sink, the heater, the temperature sensor, the FFF material delivery channel, the nozzle, and the cooling delivery system are all contained within a volume defined by the total included angle with respect to the nozzle target point.