Over time, it is possible for the delrin leadscrew block to wear down. This can introduce play into the system that decreases z-axis precision, which can cause issues with the mounting and dismounting of tools.
Once per year
Inspect the delrin ledscrew block for signs of wear. You can do this by gently pushing and pulling up and down on the leadscrew to see if you can feel any looseness in the system. If you detect there to be a large amount of play, replace the leadscrew block as soon as possible.