Thanks to my recent Cura “Print” issues I’ve been adding cooling. The detail definition on robot #4 is way better. But it’s not perfect, you can see how the air is shielded from the right side of the print and it’s curling up. I need a good airflow from all directions. This evening I’ll try out one of those donut duct designs.
The Mendel90 employs a circular duct around the nozzle which directs air downwards. Another trick it employs is to bleed a little air onto the, silicon tape wrapped, heater block to prevent convected heat causing jams with PLA at slow speeds and heavy retraction.