10. Extruder

Assemble the extruder

Please search with the keywords "BMG extruder assembly" in YouTube.

• Example video 1

• Example video 2

For the heatsink fan, insert the terminals into XH2.54 2-pin male connector as the polarity shown in the picture. Drop the Dupont connector and the extension wires included in the BMG extruder box.

For the thermistor wires, insert the terminals into XH2.54 2-pin male connector. Drop the Dupont connector and the extension wires included in the BMG extruder box.

Note that a PTFE-lined (for PLA filament) and an all-metal heatbreak are included in the hotend box (or bag) in full kits after mid-October 2021.

Printed Fan Duct

Please download and print a fan duct for a E3D v6 hotend or a Volcano hotend. (STL here)

In the slicer use supports only under the duct nozzles but not in the ducts, as shown in the pictures.

Extruder Carriage

You should have attached the extruder carriage to the X linear block at this moment. If not, please go back to Chapter 8. XY Plane.

Pancake E Stepper & BMG Adaptor

Loosely attach the inductive sensor to the printed sensor mount, and fasten the inductive sensor mount to BMG adaptor

• Inductive sensor

• Printed inductive sensor mount (STL here)

• Bolt m3 x 10 (2) (Two in the diagonal holes are enough)

• Nylon nut m3 (2)

• Washer m3 x 8 x 0.8 (2)

Attach NEMA17 pancake stepper temporarily to BMG adaptor

• Bolt M3 x 6

BMG adaptor ⇔ Extruder carriage

• Bolt M3 x 10

• Washer m3 x 8 x 0.8

BMG Extruder

BMG extruder ⇔ NEMA17 pancake stepper

• Bolt m3 x 35

Caution! Stripped threads

(2022 Aug) In this version, the thickness of BMG adaptor is higher than needed, so only a few threads in the pancake stepper are meshed with the M3 x 35 bolts. Be careful not to fasten the bolts too hard.

Since the lower 2 bolts are more important which are used to clamp the heat sink, try to fasten the upper bolt and get a feel first.

Alternatively, please drill the bolt holes of BMG extruder about 2~3mm deeper using a 6mm bit so more threads can be meshed.

In the next version a thinner BMG adaptor will be used. 😅

Fan Duct

Follow the steps to assemble the extruder carriage

4020 blower ⇔ fan duct

• 4020 blower (1)

• Bolt m3 x 20 (2)

• Nylon nut m3 (2)

Fan duct ⇔ BMG CF adaptor

• Bolt m3 x 15 (2)

• Nylon nut m3 (2)

• Washer m3 x 8 x 0.8 (4, as spacers)

Place 2 washers between the fan duct arms and the CF adaptor in case the arms are a little shorter in some earlier versions.

Here is another remote fan duct Breezer which allow you to use different air source like a CPAP blower.

Secure Wires Safely

Any movement on connectors will eventually cause failure. Ensure all wires attached to moving components are securely held/fixed in position to relieve pressure on connectors and help prevent damage to connectors and/or wires.

Also avoid sharp bending which might break shielding or wire, and cause short-circuit.