Lathe Exercises:

To get familiar with the lathe and using hand gravers I was tasked with making some center pivots and also a square shoulder pivot. The center pivots are simply a small hole in the end that comes to a point exactly at the center – they are useful for acting as a pilot hole so that a drilling operation won’t wander, or could be used to prepare the end for riveting.

To get the shoulder dimensions I used a caliper and a micrometer.

Now smaller and in blued steel:

A carbide graver was used on the steel, and getting a good point on it was critical to ensuring the shoulder was a crisp corner. These pivots took a while to get right and most of it was spent just trying to get a crisp inside corner while keeping the pivot in dimension and not tapered or bulging anywhere. I used the plates of the micrometer jaws to check the flatness of the pivot: when they closed on a good one, the whole length of the pivot would be making contact with the jaws. These are critical features because all the wheels on a clock would be turning around these pivots.