One more thing (or two)

When your local horologist was called back to take another look at the Peter Green clock he discussed addressing the problems identified by Paul and Jane (the skipping strike and the non-moving moon dial) but also pointed out that an examination of the clock may reveal other issues that merit consideration for repair. 

This was not meant to be a full service, rather an effort to fix the identified issues and discuss any others revealed. Any such issues would be assessed for risk and estimated for work effort and discussed with Paul and Jane in advance of any action such that they can assess and decide yea or nay.

The clock is about 270 years old so unsurprisingly this clock fool saw a number of problems that warranted consideration. Many of them would be ranked by this horological calibrator as "perhaps one day" or "worth considering but not essential." 

Two areas of concern pushed the horological worry meter above the yellow mark.

The first issue was corrosion. In particular there was excessive corrosion around the pin wheel that is used to drive the chiming hammers. 

Not all corrosion warrants high levels of concern, especially with a clock this old and, frankly, this well built. There was some on the hands, some arbors... bits in lots of places. Much could have been on this clock for decades or possibly centuries.

But the corrosion on that pin wheel was more serious and extensive.

The first time YLD noticed the corrosion was seeing it all along the pin wheel's gear forks as seen below. One might imagine some liquid dripping on the gear but on three of the four forks...? Hmm.

That is not a "bit" of corrosion.

Wait what is this pin wheel?

Most any clock pin wheel is design to lift, turn or stop levers in the clock. Many pin wheels look like most other typical clock wheels but have one, two or even 13 pins on it, typically along the rim of the gearing. 

Here's a typical pin wheel from Nana's clock. Those pins, when the wheel turns, lift that gray metal lever seen at the top of the image. And yes, 13 pins (one obscured by the arbor).

The chime pin wheel on the Peter Green clock is a much beefier object, very large, barrel-shaped and covered with pins along the outside surface of the barrel. As it turns those pins lift the chiming hammers. During chiming the pin wheel turns and each pin lifts a tiny lever at the base of a hammer, a bit like a music box done large. Except these hammers hit bells.

Here's that pin wheel set to lift the first hammer lever with one of its many pins.

As the barrel turns and the pin lifts and slips past the tip of the lever, the lever is released and the chiming lever spring (the flat brass strip notched to the base of each hammer) pushes the lever back down forcefully such that it strikes the bell above it.

Here's an early shot of the chiming unit clearly showing the set of hammers positioned over their respective bells and a bit of corrosion showing. The observant reader might have noticed that this photo shows the hammer being lifted by that same pin pushing the lever in the photo above.

Removing the hammers and their springs we can see more clear and possibly more problematic examples of several places where corrosion was present on the pin wheel.

YLH was concerned that the corrosion around the pins, especially the pin on the right, might have damaged the pins which, under regular use, could cause the pin to break off.

Worry wart sent some photos and spoke to Paul. It was agreed that a small effort would be made to scape away some of the corrosion to examine a couple pins more closely.

Here's that right pin carefully scraped with toothpicks and best as could be done while the whole beastie remained assembled in the movement.

The pin looks ok.

But there was still a lot of other places with corrosion and it was doctor clock's firm belief that getting to the bottom of the situation would require a full disassembly of the movement.

Which would be a big job.

And likely require opening up the almost certainly hollow barrel section of that wheel and see if something is happening inside. 

Why inside? 

That barrel is hollow and there is corrosion pooling in many spots. If something had merely dripped on the wheel it would be more limited to a few single spots aligned by gravity.

No there may be something deeper going on.

Well more photos were sent to Paul and an additional conversation transpired where the concerns and the scope of effort were discussed. 

Paul decided...

OK then...

On to Issue number 2... gear meshing.

Coming up next.