Elgin Grade 526

 This watch from a few months ago was sent back to me for not running, so I have been looking at it today.

I have firstly a general observation about Elgin's smaller movements, like this, that are earlier than movements that were designed from the ground up as wristwatches. These are scaled down pocketwatch designs, right down it seems to the mainspring. As a result the mainsprings are just too small and the watches under-powered, especially if the spring is steel, and not alloy, and is old. What this means is that in order to work well everything has to be perfect. That was one thing several decades ago when parts were cheap and available. But now... When everything in the watch is worn at least some, but it's a family piece and needs to be intact and original, it's a different matter.

I don't see this trouble in larger watches, or early wristwatches from other American makers.

To complicate matters, this is a movement, WWII era, designed for military use, and repair in the field. So, the design is such that major parts should simply be replaced rather than repaired.

This can create a puzzle. For example, this watch that was stopping... I found nothing broken. But on close inspection, the escapement has a slight "knock" - a double tap on the roller every minutes or so. This is hard to explain, but the result is that it skips a beat now and then. If everything is perfect - like when it's freshly serviced, it powers through the knock and does not skip a beat. But under more normal conditions the pallet and escape wheel can be out of sync for just an instant, and the watch stops.

Sometimes a knock is caused by a sticky or worn foot on the escape wheel, not so here, or a chip in the face of a pallet stone, not so here, or the roller jewel is loose or not straight, not so here.

 In this case it is just that all the parts are not exactly moving together as they should. The actual trouble is banking needs to be a very tiny amount more so the exit stone goes a hair further in, sooner. The amount of adjustment needed is vanishingly small. This tiny flaw would never even be noticed in the watch when it was new and everything was ideal.

Unfortunately, this watch has fixed banking pins. They can not be adjusted! Perfect right from the factory right? Well, they were good enough all those decades ago, but now I have no way to make the adjustment.

Bend the banking pin? Too dangerous. If it breaks you have a much bigger problem. My solution was to take a thin piece of hardened steel and lightly scrape the inside face of the banking pin. I literally just scratched the nickle plating. The barely visible reduction is just enough and, so far today, the movement is running strong.

This is Elgin's grade 526, 8/0 size, 7 jewels, made about 1937.