(Conducted Oct 2024, Posted March 3, 20205)

Explanation

Just got a printer 2nd hand from a craigslist . It is an Ender 3 pro with a Micro-swiss all metal hotend with bltouch bed sensor upgrades.

The first print came out pretty ugly, the bumps on the hull indicate that the print isn’t cooling sufficiently.

Given this, I turned down the print temperature and be temperature so it is easier for the filament to cool. This significantly improved results but the hull still showed slumping. The print temperature was now significantly lower than expected and much more sensitive to temperature than it should be. So I started looking for other cause of problem.

At this point, I realized the printer was suspiciously quite which led me to checking the filament cooling fan which was not running. After some poking around with settings which didn’t have any effect, I found that one of the wires for the fan had broken off. I got out the soldering and reattached it and…

Voila print #3 came out great! I threw in another filament (eSun black PLA+) I had just bought to try it out and make sure it was repeatable and also great.