This problem baffles me about a few days after installing a bowden setup consisting of E3D Titan + V6 hotend (both clones). I think I’ve figured it out.
1. Check if the hotend is clogged
Usually happens to softer material like ABS. You can check this by applying pressure by hand at the back of the extruder, so you slightly push the filament into the extruder, see if it start extruding again. If so, you’ve got a faulty gear. It just chew the filament instead of pushing it down. E3D has fixed this since 2016, I guess shitty clones just doesn’t care. I highly recommend getting a BMG dual drive clone instead of Titan, even the cheapest BMG clone gets you a better hobb than a Titan clone.
2. Hotend is definitely clogged
Usually comes together with clicking / thunking noise from the extruder. This is where the standard internet recommendations comes in. Check your retractions etc. when all that also fails, here’s what I noticed, it only happens when I print PETG (I don’t print PLA, it has no use here in Indonesia). PETG is very sticky and gooey, I can only successfully print PETG after flushing the hotend with ABS. Even that won’t last long. Another trick is to go slower, like 40mm/s or less slow. I do not have that kind of patience.
3. It’s none of the above
Check if your stepper driver and/or motor is overheated. You can easily add a fan to the board or a heatsink to the motor. A better idea actually to replace with a better driver. If you just modified direct drive extruder into a bowden one, the motor may just doesn’t have enough torque to push the filament through.
Bowden is not worth it, especially for i3 style printers. The Y axis still need to carry the bed anyway, losing the extruder motor will have very insignificant impact on speed. And the bowden setup has some weird pressure requirements within the ptfe tube, it’s just not worth the hassle of fixing a problem that doesn’t exist to begin with.
Really, even with the jankiest stock Anet A8 extruder, I have never experienced a clog nozzle, ever. Never needed a nozzle needle before I did this so called “upgrade”.