Trying to print some external PLA and am having trouble with corners curling due to not enough layer cooling. So I started looking at the fan and ducting and noticed almost no air is coming through.
Then I started the fan up away from the printer and it does indeed blow very well, even with the ducting on. Slowly moving the fan back into position under the heatsink there is a distance where the airflow stops, about a 5 mm gap above the fan. This makes me think the airflow is being choked by having the fan inlet so close to the bottom of the heatsink. I’ve made some spacers to increase the gap to 5 mm and can feel some airflow now, but the ducting is very close to the bed as a result.
This could be due to the Noctua fans I have having different flow dynamics to the original fans. Going forward im thinking of designing a fan mount and duct that has the fan positioned vertically with the inlet facing forward.
Has anyone else noticed this problem with the fan? Only really shows up when trying to print PLA.