I successfully installed a Titan to go with my E3D Volcano, and it had been working nearly 24 hours a day for the past month, but suddenly stopped working in the middle of a print and I have been unable to get it working again. Given it was working fine for a long time and nothing had changed, that points to a failure somewhere instead of a configuration error. So far I've swapped the entire hot end with an entirely new Volcano hot end twice, swapped out the motherboard, tried different STLs, different filaments, different temperatures, different speeds. With no retraction, at 40mm/s print speed filament stops moving within a minute or two. On the Titan I replaced the filament guide, verified that the filament guide is the 1.75mm model, adjusted the voltage to the extruder motor, and took the entire thing apart and cleaned it numerous times. The result is always the same-- the filament can be pushed through the hot end easily, but the Titan stops pushing filament after a couple of minutes. The wheel spins, but no filament is forthcoming. The only thing I noticed that may be a clue is when the Titan is working the filament is in the middle of the hobbed gear. When it stops extruding the filament has drifted to the extreme left of the hobbed gear. This is possible since the plastic 1.75mm marked filament guide has a hole that's much larger than the filament. At first I thought it was the 3mm version, but its got 1.75mm stamped right on it.