Removing Filament Stuck in the Hot End

Filament can get stuck in the hot end if heat creeps up into the heat sink because this area has a larger diameter than the rest of the hot end. It can also get stuck if the filament breaks when it is being extruder, causing it to get stuck below the filament drive gear. Therefore, filament is blocked from being extruded through the hot end and it needs to be manually removed. To remove stuck filament, please follow the steps for the case that pertains to you:

Portion of filament sticking out of hot end:

1. Remove the fans from the hot end.
2. If the filament is long enough such that you can grip onto it, perform steps 5 through 6.
3. If the filament is long enough such that you can NOT grip onto it, perform steps 4 through 8.
4. Remove the hot end from the extruder body by first unscrewing the bolt on the front of the extruder body that secures the hot end Gently remove the hot end, but leave the heater and thermocouple wires plugged in.
5. Being careful not to put any force on the heater cartridge or thermocouple wires, grip the hot end by the heat sink with a pair of pliers or other heat proof device so that it won't move when pulling on the filament.
6. Starting from room temperature, use the Viki to set the hot end to heat up to the printing temperature of the filament that is in the hot end, and simultaneously start pulling the loose end of the filament out of the top of the hot end until it releases.
7. Immediately stop applying heat by decreasing the temperature on the Viki. This is important to prevent heat creep from melting the filament in the heat sink region.
8. Reinstall the hot end into the extruder body, attach the fans, and go through the calibration procedure outlined here - Step 1 then Step 2 - to get the machine ready for printing again.

No filament sticking out of the hot end:

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1. Start by removing the nozzle from the hot end by following the steps in the first 1.5 minutes of our nozzle change instructional video here: Link
2. After the nozzle is off, replace the fans and let the hot end cool back down to room temperature.
3. Set the hot end to heat up with the Viki and simultaneously start pulling the loose end of the filament out of the bottom of the hot end until it releases.
4. Once it releases, immediately stop applying heat by decreasing the temperature on the Viki or removing the heat source. This is important to prevent the extruder body (if the hot end is still in it) from melting.
5. If the filament doesn't come out of the bottom of the hot end, then you will need to remove the hot end from the extruder body by first unscrewing the bolt that secures the hot end into the extruder body. Gently remove the hot end, but leave the heater and thermocouple wires plugged in.
6. Set the hot end to heat up again, except this time unscrew the heat sink from the heater block.
7. After the heat sink is removed from the hot end, a longer length of filament should be exposed.
8. Let the hot end and filament cool down to room temperature again.
9. Set the hot end to heat up with the Viki and simultaneously start pulling the loose end of the filament out of the top of the heater block until it releases.
10. Reassemble the hot end according to this video - Link - and tighten the nozzle to 34.5 in-lbs of torque
11. Reinstall the hot end into the extruder body, attach the fans, and go through the calibration procedure outlined here - Step 1 then Step 2 - to get the machine ready for printing again.

Questions or comments? Please reach out to us at [e-mail] and we will assist you. Thanks!