The Dual Extruder V3 suffers from an abnormal amount of heat creep issues. This can be solved in multiple ways.
- Purchase and apply LulzBot’s Dual Extruder V3.1 upgrade kit.
- Print and install the fan duct described in this thread.
- Search the internet for other fan duct solutions.
Option 1 will reduce the amount of heat creep issues but, IMO, not as much as option 2 or option 3. You do not need option 1 if you go with option 2 or option 3.
I am happy with option 2 but I remember seeing other options when I was researching option 2.