Updated version of our experimental syringe extruder, it is designed for a 60ml syringe which is the perfect dimension for our printing need. 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.
-For the main body we had to design a very big part, around 30cm in lenght. In the next future the main part splitted in 2 smaller parts will be provided in order to be printable with all most common FDM machines.
you will need:
-3Drag printer (https://www.futurashop.it/3d-e-cnc/stampanti-3d/stampanti-3d-1/3drag-stampante-3d-versione-1.2-in-kit-7350-3dragk)
-6x 30mm M3 bolts and nut
-2x 20mm M3 bolts and nuts
-1x M8x170mm rod
-1x M8 nut
-1x 608zz bearing
-2x C profile 133mm (6x6x1 thichness)
-4x diam 3mm x 15mm long self tapping screw
-a lot of Inj/Light 60ml Luer Lock (http://www.doctorshop.it/Prodotti/Siringa-INJ-LIGHT-latex-free-a-3-pezzi-da-60-ml-cono-luer-lock-senza-ago-6400048)
-For setting up the printer you have to determine the right E-step for your extrusion stepper (our value is 12500 steps for 1 mm of filament).
Slow down your extrusion speed around 0,5mm/s, and try to extrude 10mm of material. Measure the movement on the syringe, and solve this formula:
NewEstep = OldEstep x NominalDistance (extruded from software) / MeasuredDistance (real movement)
Set the new E-step and repeat the procedure. Once you are near to right value try with bigger extrusion distance like 50mm or 100mm to make a more precise calibration.
-In the slicer software you just have to set:
Filament diameter to 29mm (inner diameter of the syringe)
Nozzle size around to 2mm (you can change it a little on the real value)
-Check if you have enough material for the print, in Cura you can see how many meters you are using for the print. The syringe is long around 100mm, so you can use 0,1m maximum