E3D Fan Duct Improved Flow

thingiverse

**Update** In an effort to enhance this via testing, I discovered a significant increase in airflow of approximately 2%, although it's hardly worth it, and I suspect that the airflow may be concentrated through smaller areas of the heatsink, reducing its overall effectiveness. The fifth iteration (E3Duct V5) appears to make a notable improvement in cooling, with input from others helping to derive this design. However, there is still room for improvement; if you'd like to test its effectiveness, please print it and share your results. In an effort to build a quieter and more efficient machine, I examined the E3D fan duct while using a genuine E3D V6 24V hotend and a 30mm fan, which is the noisiest component after upgrading my stepper drivers. My goal was to improve airflow and then reduce fan speed to decrease noise and extend its longevity. These axial fans tend to rapidly lose flow when their airflow is restricted, and the fins on the E3D hotend provide sufficient restriction to greatly reduce airflow while the fan works hard. After adding a second set of stationary fins in the duct, I found that airflow increased substantially. If you compare this modified duct with an original one without a heatsink in place, you'll notice little difference except for a slight increase in noise, which may seem like a step backward. However, if you install a heatsink, airflow will be considerably higher than before. Now, it's up to you to decide: improved cooling or reduced fan speed – and if you find the optimal balance, both noise reduction and improved cooling can be achieved. I've rearranged the internal fins to align with the fan motor spars since they may cause some turbulence and I'm trying not to introduce any additional issues. The reason for only three fins is that having six fins would likely increase friction without providing any further improvement.