I’m thinking of creating a fan duct for my Printrbot Jr. Where is the best place to have the airflow directed? Down at the print? Across the top of the print? At the tip of the nozzle? Main body of the nozzle? Thanks!
I would say near the tip of the nozzle, this will limit the cooling to the last layer area and no so much the entire object. Overall object cooling will cause contraction in ABS and may cause parts to pop off the bed.
I tried a few and had best luck with a “duct”-type that surrounds the nozzle directing air at the fresh extrusion vs. the entire object (and not right on the nozzle itself).
You’re using PLA correct?