There are three different middle sections of the shaft. I assume I need only one of them, and the total length of the pendulum shaft will determine the period. Is it recommended to print all 3 and try them on for size?
The shaft sections snap together, but is it a good idea to glue them once the correct length is found?
pendulum_shaft_mid is the nominal length shaft to start with. The long and short sections are only needed if you need more pendulum length adjustment range. This should only be needed if your pendulum bob or shaft density is different than mine.
The pendulum shaft holds its position without glue. And adding glue makes it more difficult to move the clock.