Status: version 3.1, beta testing

View 3D CAD file: https://wikifactory.com/+fabmxteam/fabmx/file/PelletExtruder/Version3.1/PelletExtruderv3.1.step

Github repository: https://github.com/ProjectFabMX/FabMX_Extruder


BOM

ItemAmountDescriptionSource of supplyComment
Extruder Screw1extruder screwcustom part, steel, drawing/parameters
Extruder Barrel1includes mount and water cooling channelscustom part, steel, see step file
Nozzle1standard 3D printer nozzle, type E3D V6 1.75mm; optionally hardenede.g. https://e3d-online.com/products/v6-nozzles?variant=40924117598267Typical nozzle diameters are 0.4 or 0.6mm
NEMA 23 Stepper Motor with gear box1see notes below

Shaft Coupler1rigid shaft coupler 10mm to 12mm, D=max30, L=40e.g. https://www.dold-mechatronik.de/Wellenkupplung-starr-D30L40-1000-1200mm
https://www.aliexpress.com/item/32845730754.html
do not use flexible couplers, they cannot take axial load
Heating cartridge240W, 24V, 6mm x 30mm

Metal Cage1several laser cut aluminum partscustom parts, aluminum 3mm, laser-cutting folder on github
Pellet Inlet1
custom part, PLA/resin, 3d printed, see github
Pellet Tank1
custom part, PLA/resin, 3d printed, see github
Temperature Sensor1standard thermistor for use with 3d printer controller board (e.g. 100K NTC)




M5x1104steel screw

M3x84


M3x202


M3 brass insert6
e.g. https://cnckitchen.store/products/gewindeeinsatz-threaded-insert-m3-standard-100-stk-pcs
Pneumatic fitting G1/8"2Fitting G1/8" for 4 or 6mm tubinge.g. Festo QSML-1/8-4-100for water cooling
Closing plug G1/8"1Closing plug G1/8" hex sockete.g. https://www.landefeld.de/artikel/en/closing-plug-hexagon-socket-g-18-brass/VS%2018%20MS%20OB

To run the extruder you will also need a water chiller for cooling. Alternatively, just use a water pump and a water reservoir (>3 liters)

We are currently mainly using PolyMIM materials, as these feedstocks can be debindered easily in a water bath.


Motor/Gearbox

The extruder uses a NEMA23 stepper motor with gear box. It needs to have the following specs:

  • The gear box needs to have 4 M5 threaded holes for mounting, lying on a circle d=45mm
  • The gearbox shaft should have a diameter of d=12mm. Use a different coupler if the shaft has a different diameter
  • The gearbox diameter should be D=56mm or smaller
  • The length of the motor and gearbox are noncritical for the design. Typical sizes are L1=60mm and L2=56mm
  • The gear ratio should be in the range of 1:15 to 1:47. A gear ratio of 1:28 seems to be a good compromise, but is hard to get

Sources of supply:


Size/Mounting Holes




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Licensed under the CERN-OHL-P v2
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