A three dimensional printer which prints at using at least one composite material having an inherently abrasive filler or fiber material has a Mohs hardness greater than substantially 1, or a Knoop/Vickers hardness greater than substantially 300 kg/mm2, or a Rockwell C hardness at least C30, and where a nozzle tip may contact a top surface of a previously deposited line of material may have a nozzle body includes a material having a thermal conductivity at least 35 w/M-K to conduct heat to the nozzle, and a nozzle throat and/or nozzle tip each include a material having a Rockwell C hardness at least C40, to resist wear from sliding contact of the nozzle tip with the previously deposited lines of the material being printed or another previously deposited material, or from the material being printed as it is printed through the nozzle throat.