I was practicing printing Autococker barrel threads.
With my Ender 3, I have to use a 3A tolerance in Fusion360, or the threads are too tight. I have also found a lubricant makes all the difference in the world, as PLA seems to want to gall very easily. I was using coco butter, as it was handy, and it was a container that Jen did not like.
3 unsuccessful and 1 successful test...
A mostly successful print. The barrel can be used for testing, but the shank is about 3/16" short as it broke loose from the build plate with about 10 minutes left of a 7 1/2 hour print