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Cleaning the Extruder

Cleaning the Extruder

You will need...

  • 2mm hex driver
  • 2.5mm hex driver
  • 4mm hex driver
  • 5mm hex driver
  • small bristle brush

Lower the bed by 200mm to facilitate ease of access. Unload the filament from the extruder. If the filament has jammed and is stuck, cut the filament off just above the extruder and leave the extruder lever open.

Ensure printer has cooled to room temperature before continuing. Turn the printer off to perform maintenance.

Drop hot end assembly

Disconnect the heater and RTD electrical connectors from the hot end. Loosen the set screw in the bottom probe plate and drop the hot end assembly.

Note

Be careful not to lose the small piece of PTFE tubing seated in the hot end assembly. It is a crucial piece of the filament feed path.

drop hot end

Move the probe limit switch

Remove the two M5 screws holding the probe switch bracket. Carefully move the switch assembly to the side.

remove M5 from limit switch bracket

Remove the probe assembly

Remove the bottom plate (1 M4 bolt) and the top plate (2 M4 bolts)

Note

The springs are loose - take care not to lose them!

remove probe plates

Detach the extruder assembly

To detach the extruder assembly from the toolhead plate, remove the bolts in the top and bottom of the extruder (1 each)

Note

The cooling loop and electrical cable will hold the extruder assembly in place - leave these connected!

detach extruder

Open the extruder

Note

Take care when opening the assembly – there are a few small, loose components.

Rotate the extruder assembly 45 degrees, resting on top of the tool plate. Remove the 2 bolts on the front of the extruder assembly.

open extruder

Separate the front two sections (the extruder) from the back section (the motor). Remove the gear assembly shown in the photo below.

separate extruder

Carefully remove the lever assembly by unhooking the spring (circled in green) and removing the bolt.

remove lever

Cleaning the gears or clearing a jam

Clean out any visible filament debris. Use a small bristle brush to clean out the teeth on the filament drive gears.

clean extruder

Reassembly

Reassemble the extruder sections, replacing the bolt and spring on the lever assembly. Fit the extruder sections back onto the motor. You may need to fiddle a little to get the gear teeth to mesh. Replace the 2 front bolts.

Reinstall the extruder assembly onto the tool head plate, replacing the bolt on top and on bottom.

Reinstall the probe plates. The top plate has 2 bolts and must be square with the tool head plate. Place the springs on the posts and bolt in the bottom plate (1 bolt)

Tip

To get the springs and bottom plate in place, hold two springs with one hand and hold the plate and third spring with the other.

Reinstall the probe limit switch assembly using the two M5 bolts. Be careful with the cables as they can be delicate.

Ensure the small piece of PTFE tubing is seated in the hot end assembly. Line up the hot end assembly so the PTFE tube is inserted into the hole in the probe plate, and the top of the cooling block is flush with the bottom probe plate. Tighten the set screw. Be sure that the hose clamps on the heat sink do not interfere with the movement of the probe assembly. Reconnect the heater and RTD electrical connections on the hot end assembly.

Checkpoint - Visual Inspection

  • No parts left over
  • All connectors are attached
  • Hot end is securely mounted
    • You should not be able to wiggle the hot end assembly in its mount in the probe plate
    • The top of the heat sink should not pass the top of the lower plate of the probe assembly
  • Probe assembly triggers smoothly
    • Push up on the bottom of the hot end assembly to ensure the probe switch triggers smoothly

Checkpoint - Test Procedure

  1. Power on printer.
  2. Power on hot end to 50 C
  3. Ensure temperature holds
  4. Increase to operating temperature
  5. Install filament and engage extruder
  6. Extrude material

last updated 27/9/2018