OHAI: Open Hardware Assembly Instructions

1 Gather materials

Aerostruder Tool Head that needs a new hot end
Replacement hotend assembly [KT-HE0008]
2.5mm hex key
Some sort of tool with a small point (Pin removal tool works well: https://www.molex.com/pdm_docs/ats/ATS-011030043.pdf)

Materials

2 Remove the heatsink fan

Using the 2.5mm hex key, loosen and remove the four M3 screws that hold the fan onto the heatsink.

Location of fasteners in green

Removing

Heatsink fan removed

3 Remove the blower fan and duct

Loosen and remove the four heatsink mounting screws and remove the fan duct by sliding down off the bottom of the toolhead.

Location of mounting screws in green

Removing

Removed

4 De-pin the heater

Using the pin removal tool, carefully remove the pins for the heater.

Note: this step is only required if the hot end assembly needs to be replaced.

Latch side up, two heater pins in green circles

Probe both sides and pull firmly on the lead

5 Disconnect the thermistor

Depress the retention tab on the connector housing and disconnect the thermistor extension. At this point, the hot end assembly can be lifted and removed.

Thermistor

Thermistor disconnected

6 Remove the hotend-heatsink assembly

Remove the heatsink assembly. Loosening the idler compression screw can help. Turn clockwise to decompress the spring.

Remove filament guide from filament if necessary

7 Inspect the extruder mechanism

Inspect the bearings, hobbed shaft, idler arm, guide tube, and drive gears. Clean and replace parts as necessary.

Specifically, look for plastic or worn teeth on the hobb, cracks or wear on the idler or guide, or excessive wear or missing teeth on the drive gears.

8 Transfer the bearing

Remove the bearing from the old heatsink and install it in the new heatsink. A spare stepper motor shaft is a good tool to remove the bearing. Just push the shaft into the bearing and then wiggle and pull the bearing out.

Bearing removed from old unit