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Item | Amount | Description | Source of supply | Comment | |
---|---|---|---|---|---|
Extruder Screw | 1 | extruder screw | custom part, steel, drawing/parameters | ||
Extruder Block / Kühlblock | 1 | holds barrel; integrated water cooling | custom part, steel, drawing | ||
Extruder Barrel / Schneckenzylinder | 1 | screws into extruder block | custom part, steel, drawing | ||
Nozzle | 1 | standard 3D printer nozzle, type E3D V6 1.75mm; optionally hardened | e.g. https://www.aliexpress.com/item/4000463888666.html | ||
NEMA 23 Stepper Motor with gear box | 1 | use a gear ratio of 1:20 to 1:45 | e.g. https://de.aliexpress.com/item/4000341116560.html longer NEMA23 optionalsee notes below | ||
Shaft Coupler | 1 | shaft coupler 10mm to 12mm | e.g. https://www.aliexpress.com/item/4000002010204.html | ||
Heating Element | 1 | 230V heater spiral, ID=15mm, h=40mm | e.g. https://www.aliexpress.com/item/32629957364.html | wraps around barrel | |
Metal Cage | 1 | several laser cut aluminum parts | custom parts, aluminums 3mm, see laser-cutting folder on github | ||
Pellet Inlet | 1 | custom part, PLA, 3d printed, see 3d-printing folder on github | |||
Pellet Tank | 1 | custom part, PLA, 3d printed, see 3d-printing folder on github | |||
Temperature Sensor | 1 | standard thermistor for use with 3d printer controller board (e.g. 100K NTC) | e.g. https://www.ebay.de/itm/321913407822 or thermocouple integrated in above heater element, then use this temperature controller (not compatible with typical 3d printer hardware): https://de.aliexpress.com/item/32954616330.html?spm=a2g0o.cart.0.0.23af3c00hLDu73&mp=1 | ||
M5 x 120 | 4 | steel screw | |||
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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 gear 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
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