bdux

Well, I did everything: cleaned it all, removed everything, readjusted everything, tightened everything, printed a quick test file and everything worked. Then I put a big print job in to print over night. This time I left a camera running on it. The footage is not quite regular enough to see exactly what happens but it looks like the start of the problems is the bed dropping in the Z direction suddenly. This is when the 'explosion' occurs as the printer starts to print in to the air. The blob happened again but it is not clear why from the film. Disassembling the print head again has shown that the problem is worse this time and that the material seems to be coming out of the side of the nozzle and heater block. PTFE coupler does not look as bad as the ones in the Ultimaker examples but I will certainly replace that. The voyage continues!

Thank you. I will print a spacer I think.

Thank you Neotko for sharing your experience. I will look into everything that you mention and, when I can get the printer working again, try the spring replacement.

Thank you Nicolinux, I have thoroughly cleaned and re-greased the z-screw, it is running smoothly. Whilst I was doing this I noticed that there is a lot of 'play' in the x-axis, each time the machine moves from left to right and back the whole bar connected to the motor that carries the print head pops in and out a few mm. I have tried lubricating the support bars too (with oil as instructed, not grease) but this hasn't improved things much, am I missing a washer or some sort of spacer to stop this movement? I didn't assemble this machine, it arrived pre-assembled in the box.

Thank you Neotko, I have not installed a new nozzle but I went inside the print head to have a look anyway. I heated up the nozzle using the advanced settings as I don't have a hairdryer and everything came apart easily. Although there was nothing that could have been done any tighter I did discover a burned blob that looked like it might have been extruded through a gap. Since there does not appear to be any way of loosening or tightening the nozzle I'm stuck for what I could do. Any suggestions? Thank you for your advice and suggestions Kind regards

In the early days I just pressed print on my Ultimaker 2 extended and a few hours to days later I would have a very nice print job. Following a more recent run of the printer apparently making up its own mind about what it was going to print (the output was neither like the Cura file nor the original design) and not getting anything that we wanted out of the printer I have spent a long time on this forum looking for answers. I am printing in ABS. I have followed all the advice and instructions on leveling the table, cleaning the nozzle, setting the temperatures and speeds, putting glue stick on the bed... and finally the printer started (all be it very slowly) exactly what we wanted. So after 2 hours I left it. And I came back to it this morning: You can see the base in the photo, perfectly flat and square on the buildplate You can see what looks like an explosion of really fine wire The thing that has me really worried because I can not work out how it could possibly have been printed is the long totally solid blob of plastic attached to the print head. This blob is also continued inside the plastic fuzz. The fuzz also is, I just discovered, sandwiched under the buildplate. I can't afford the time or plastic for this to happen again but my primary concern is what is going wrong and how do I fix what is clearly a really messed up print? Thank you so much for any time and advice you can give me