You are right, it has to be a heat creep issue. When I start from a cool toolhead and set my hotend to 183* it fails about 15 minutes into the print, but when i set it to the recommend 205* it fails 5 minutes into the print. Why doesn’t Lulzbot address this issue by upgrading their toolhead with adequate fans? I bought this for PLA & PVA and the fact that is doesn’t work without mods is kinda silly. Thanks for the link, I just ordered the fans. I wish there were still stores that sold these so I didn’t have to wait for them to get here. Im also wondering if I print them with the polycarbonate that would make the ducts more resistant to higher temps for ABS. What do you guys thing?