Well I purchased an E3D indirectly when I bought my Prusa mk2s. It worked perfectly on this unit by I changed the Prusa to run a Flexion. I decided to put the E3D to use on my Hypercube Evolution and setup as bowden. At this point I started running into problems. It prints well for the first hour or so but then gets progressively worse and then clogs. I looked at all the online resources (I try not to be the guy who asks a question that I could easily have googled). This narrowed my problem to the heat sink which was hot. I have tried multiple solutions 1.) Checked the PTFE tube sits in completely 2.) Changed the fan and ensured it is blowing correctly I have just dissassembled everything and started cleaning it out but nothing obvious there. I did not disconnect the heat sink from the heat break and have not touch it since I assumed it was done correctly at Prusa and I do not have the thermal compound. Any advice on troubleshooting this further?