Ultimaker 2 ticking sound coming from feeder Recently, the ticking sounds started to come from feeder of my UM2. Inspecting it I have noticed that once in a while stepper motor jumps back for few steps. I have an idea of what can be the reason, but I just want to hear what you can think of. That is the video of feeder during the printing :)
https://youtu.be/z6CzudMOeD0 First tick at 10sec
Ultimately, your stepper motor is unsuccessful in driving the filament through the extruder. A couple potential reasons:


extruder temperature isn't high enough. This could either be operator error from not setting the temperature correctly or your machine is getting a false reading. Typically, for ABS/PLA, you can get away with a low extruding temperature of about 210c.
filament tension is too high. This happens if, say, your spool of filament gets kinked or wrapped around the spool spindle.
your nozzle is clogged. I've encountered where I had back flow coming out of the nozzle (filaments oozed around from the hotend at the threads). This was a result of not putting the hotend back together correctly. There was a enough hardened plastic backed up in the hotend that when I threaded the nozzle back on, it technically didn't fit back on all the way.