How it works is that the Universal print head prints each layer at a rate that allows it to cool to the proper temperature for adhesion before the next layer is applied. If the layer is too hot, print speed is reduced to allow it to cool before the next layer of material is deposited. If the layer becomes too cool, print speed is increased. A built-in thermographic imaging system displays a real time image on the CNC control screen, allowing the operator to maintain the ideal temperature throughout the 3D printing process.
The LSAM Universal Print Head can achieve temperatures of up to 450ºC, and uses a Siemens temperature control module integrated within the print gantry CNC control. Each print head can be equipped with one of three interchangeable “melt cores,” which consists of a feed housing, extruder and polymer melt pump. Each melt core has a different maximum print rate, which determines the longest bead that can be printed during the cooling time between layers.
The LSAM 3D printer is equipped with a 40mm melt core, which includes a patented 40mm high speed extrusion screw with a corresponding melt pump and print head. This melt core is capable of 3D printing 150 pounds of material per hour, and can create parts with a print layer lap length of up to 175 feet while printing a bead that is .200 inches thick and .830 inches wide. If longer bead layer lengths are required, a 60mm melt core can process 50% more material, and a 70mm melt core can 3D print over 500 pounds of material per hour. The higher output melt cores do, however, have a minimum operating speed so may not be suitable for smaller parts.
In operational tests, the 40mm melt core was able to print 20% carbon fiber reinforced ABS as well as 40% and 50% carbon fiber reinforced PPS. This was using the 10′ x 10′ LSAM machine; the Universal print head will also be installed on a 10′ x 20′ demonstration machine, which is currently under construction. Discuss in the Thermwood forum at 3DPB.com.