While printing a second VR headset, this time on my Airwolf3D 5.5, the hot-end broke in two. :-( I wasn't monitoring the printer at the time, and looking at the remnants on the printbed doesn't tell me much. Somewhere the Z axis alignment was off, the print head smashed into a part on the bed and broke the print head in two. I don't know how many hours of printing I've done with this hot end, but it has been quite a lot. I think 5 or 6 kilos of plastic have run through it in the last 10 months. I've been wanting to upgrade this to the new Airwolf3D Jam Resistant hot end, so now's my opportunity. Here's what the hot-end of the extruder is NOT supposed to look like.