Project developed at the +LAB, a 3D printing research lab focused on low-cost 3D printing, and material development for 3D printing technologies, of the Politecnico di Milano.
The files needed to assemble the extruder are on our thingiverse, and can be downloaded and printed on any lowcost FDM 3D printer.
The extruder is designed for a 60ml syringe which is the perfect dimension for the lab experimental printing needs. The syringe model is a luer lock type, which means you can use a lot of different nozzles from the luer lock system.
The extruder is designed for a 3Drag printer (K8200), but you can easily adapt it to other system by designing a customized mount for your machine. 3Drag is a moving bed machine, so the extruder is still during the print without any issue of moving weight. If you use this on other printer models remember to slow down all head movements like print speed, travel speed etc.
The gear reduction ratio is 5:1, which is enough for printing in clay, but not enough for more viscous materials. This ratio has been decided for dimensional constraints of 3Drag printer, but for other machines a 6:1 or 7:1 ratio it is recommended.