I have had my Robo 3D R1 for a couple years and the last couple months have been nothing but one challenge after another. The hot end just started getting clogged over and over. I would unscrew the very tip and that worked at the beginning, but then wasnt enough. I purchased a new tip, but that didnt work. I purchased a new "heater cartridge" for the block and a new "thermistor" and replaced that and it seemed to work but it starting clogging again. so i bought a whole replacement hexagon hotend from robo3d and replaced it all which had the tip, the barrel and the thermistor... and it still clogs. i cant post links to show what i am talking about but the PLA (yes, tried 8 different spools to see if was vendor specific, or color) gets stuck in the top part of barrel in the shaft on the way to the hot end. I now have 2 barrels , the old one and the new one i bought with clogged PLA that i cant remove because the hot end doesnt heat this section up. I am going to take a torch to it tonight to see if I can get it operational. I think i am talking about (which requires me to loosen the quick release plate to access) : 1) the heat sink (fins) 2) the heat break what am i doing wrong? or what should i check?