Extruder cooling mid print issues, but with wierdness.

I’ve discovered an extrusion issue I haven’t ran into before, and it kind of has me baffled. I’m trying to print the side plates of my ROV thingy (http://www.thingiverse.com/thing:451236) which is admittedly a very long print. But it seems to be wanting to stop extruding plastic mid print. I’ve got great plastic flow up until the point it stops, but it does eventually stop. Before it was stopping about 3 hours in. now it’s stopping about 30 seconds in. The wierd part is the printer LCD and the software both seem to think that the hot end is heating to temperature, don’t indicate a drop in temperature, and seem to actually be reporting the correct temperature at the beginning of the print because it extrudes correctly at that point. At the point it stops cooling, the filliament is very difficult to retract or pull out by hand, but if i restart the machine and re-heat the extruder it comes out fine.

What’s wierd in this instance beside that, is that I actually have a second complete known good hotend to try in that machine, and it’s doing the same thing, so I don’t believe it is the thermistor or the heat element.

Diameter of the filliament is fine, it’s good quality filliament, moisture content is pretty low in the air today, there is no mechanical blockage in either nozzle, and it’s likely not the nozzle itself. So, I’m stumped. if this was a fuse issue i’d expect it to be either working or not.

Any ideas? I’ll try a different interface program to see if that helps, but i’m not hopeful.

Edit: the extruder motor and gear train shaft set screw, etc. are working fine throughout this , and end up digging holes in the filliament.

Nevermind, it was mechanicle. Did you know theidler latch arm bolts can punch through the side of the extruder body itself from spring tension? Spare extruder body is now on, seems to be fine now.

Mind posting a picture of the original extruder body?


I’ll see if I can retrieve it from whence it is gone to…