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
Item | Amount | Description | Source of supply | Comment |
---|---|---|---|---|
Extruder Screw | 1 | extruder screw | custom part, steel, drawing/parameters | |
Extruder Barrel | 1 | includes mount and water cooling channels | custom part, steel, see step file | |
Nozzle | 1 | standard 3D printer nozzle, type E3D V6 1.75mm; optionally hardened | e.g. https://e3d-online.com/products/v6-nozzles?variant=40924117598267 | Typical nozzle diameters are 0.4 or 0.6mm |
NEMA 23 Stepper Motor with gear box | 1 | see notes below | ||
Shaft Coupler | 1 | rigid shaft coupler 10mm to 12mm, D=max30, L=40 | e.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 cartridge | 2 | 40W, 24V, 6mm x 30mm | ||
Metal Cage | 1 | several laser cut aluminum parts | custom parts, aluminum 3mm, laser-cutting folder on github | |
Pellet Inlet | 1 | custom part, PLA/resin, 3d printed, see github | ||
Pellet Tank | 1 | custom part, PLA/resin, 3d printed, see github | ||
Temperature Sensor | 1 | standard thermistor for use with 3d printer controller board (e.g. 100K NTC) | ||
M5x110 | 4 | steel screw | ||
M3x8 | 4 | |||
M3x20 | 2 | |||
M3 brass insert | 6 | e.g. https://cnckitchen.store/products/gewindeeinsatz-threaded-insert-m3-standard-100-stk-pcs | ||
Pneumatic fitting G1/8" | 2 | Fitting G1/8" for 4 or 6mm tubing | e.g. Festo QSML-1/8-4-100 | for water cooling |
Closing plug G1/8" | 1 | Closing plug G1/8" hex socket | e.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:
- https://de.aliexpress.com/item/1005003850399817.html
- https://www.omc-stepperonline.com/nema-23-stepper-motor-bipolar-l-56mm-w-gear-ratio-15-1-planetary-gearbox-23hs22-2804s-pg15
- https://www.omc-stepperonline.com/nema-23-stepper-motor-bipolar-l-56mm-w-gear-ratio-47-1-planetary-gearbox-23hs22-2804s-pg47
Size/Mounting Holes
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