Unanswered Clogging during prints

This is getting out of hand, I fire off a print job, and about 4 hours into the print I find the extruder has clogged up with the printer of course driving right along without anything coming out...

It's seems to be consistent , I'll clear out the clog, and run it again about the same time / place it clogs up again.

This last time i was manually oiling it every half hour or so, (oiled a foot of filament at a time) and Blew air on the stepper motor to help cool it down a bit.

 

Yes, the small fan appears to be running fine, the large fan is having issues keeping up though.

 

Thats what I was thinking, well not so specifically but I was thinking it has something to do with process temps.

I've swapped to an older Extruder, re-arranged the wiring, cleared the clog, etc. both fans are working full speed and correctly. I'm running the same print through Simply3d vs the matter control that I tried yesterday. here's hoping!

This is by far the largest and longest printed object I've attempted, and of course it's one I designed from the ground up and reallllly did / do what it printed for use.

 

Welp that didn't work either.

this time it stopped laying plastic before the first pass was complete. both fans were running, this time its a jam, / clog I'll have to run a heated element down the heat sink to free it up.