Case of the Squeaking 3D Printer

My 3D printer was making a squeak-like sound today. A friend helped me figure out what was wrong. The PTFE tube had some problem so it had to be replaced. After replacenment I printed another calibration cube. Mostly because it's been a few weeks and it's an easy way to determine if there are any other problems I haven't noticed yet.

The bottom was a little deformed but I think that's due to not having the slicer settings quite right. Not enough time to print a second cube to verify that assumption so I'll print another one tomorrow. That will make six calibration cubes for the collection I seem to be starting.