Hot end clogging


I’ve been troubleshooting the nozzle on our TAZ 2 for the last week and a half and I have run out of ideas. It was printing fine with black PLA. I switched over to silver PLA and that’s when the clogging started. I was printing a pretty big part (30 hrs or so). With about 25mm left in the z, the nozzle clogged and didn’t print the rest of the part. I have a modified fan mount blowing on the part as well as the 5 aluminum heat sinks on the nozzle so as to not allow the heat to creep up the nozzle and jam that way. I was printing at 184 C with black PLA and it was working perfectly.

Since then I have tried many things to get it to print without clogging again to no avail:
I tried switching back to black PLA with the exact same settings and it continued to clog.
I went back to silver PLA and tried increasing the extruder temp. I tried 5 degree steps from 184 to 220 and every single time it clogged.
I then replaced the smaller gear (I had some trouble with this in the past).
I tried different tensions on the spring screws holding the filament against the knobbed bolt.
Finally, I completely disassembled the nozzle and cleaned it as well as I could, reassembled, and tried again and it stilled clogged.

I have a new nozzle being ordered today (hopefully) because I have done everything I could think of to do.

I thought I’d ask the forums to get any other ideas to try before the new nozzle gets here.