Escapement

Last weekend your correspondent larked over to this estate sale, mere minutes from horology HQ. Now before going any further it is important to point out that generally speaking this clock fool is not particularly enamored of tall case clocks (AKA grandfathers).  The clock world is flooded with often cheaply made tall cases from the 70's and 80's. With the same scrolled look and Tempus Fugit invariably stamped on the top of the dial, they are uninspiring and many are made with low quality movements that don't last more than a couple decades and are hardly worth repairing. But your inquisitive horologist keeps an open mind and regularly scans the local Monterey Craigslist  for horological finds. Searches for clocks typically result in wide varieties of time pieces surfacing for sale and almost invariably include one version or another of a mass produced tall case, being either given away for free or ineffectually over-priced. The market is not kind to tall cases these days. ...

In our last episode I indicated that I had run into another issue with Nana's clock . I'll get directly to it.  When one of the two mainsprings unwinds / uncoils it rubs up against one of the internal wheels of the clock movement, stopping the clock. It's the time train mainspring that is the culprit. You may recall that your local horologist discovered this issue while timing the movement. Nana's clock had run for several days untroubled.   But one morning I discovered it had stopped.  It had been fully wound and stopping after a few days was unexpected.  A quick look at the clock suggested no obvious reason. The mainsprings seemed to have plenty of room to still uncoil and power the clock. Keep in mind the movement was still fully installed in the case and I had just taken a peek. It was only after removing the movement and inspecting it that I understood what was happening. The time train mainspring, as it was uncoiling, had run up against the "shroud" of ...

In our last episode  we got Nana's clock movement installed back in the case and it was striking nicely. It's exciting because those results leave this clock fool no doubt that we will get the clock running well. Most well-made American clocks that are serviced, maintained and in good shape can often be accurate to within 1 minute a week. Some can do even better.  Time adjustment is a regular part of any mechanical clocks service and maintenance. Even when in tip top shape a mechanical clock will often need at least tweaks of its timing. And Nana's clock movement did need time adjustment.  Furthermore after a full service there's a lot that can be discovered about performance and potential problems by just letting the clock run for several days or even weeks. Mechanical clock speed is driven by the gearing ratios of the movement wheels and the rate that the pendulum swings back and forth.  The gearing (wheels in the movement) is essentially fixed and with the right ...

After my brief spin in the Mystery Machine I got Nana's movement running well, both keeping time and striking. Giving the case a gentle clean I noticed quite a bit of tar on the exterior however that is not unusual with antique clocks. Smoking was much more prevalent decades ago. Nonetheless, overall, the case is in good shape and I wanted to see how the clock would run with the movement fully installed.  To reinstall it the movement is inserted face down and screwed into the frame of the case. I turned her over, reinstalled the hands and stood her up. The movement seated upright nicely. Didn't those original mainsprings clean up well! Then I aligned the hammer to the gong. And hooked on the bob on the end hook of the pendulum rod. Now up on the table to do a test run. Fully reinstalled and standing tall the movement ran quite well. I did some time testing which means checking to see if the clock runs fast or slow. After a full service of a clock movement it is important to le...

Nothing like a good mystery. When having dinner with Ted last weekend I mentioned that there was a part in the movement of Nana's clock that I had never seen before.  When I was first inspecting the movement, right out of the case, I noticed a little piece of curved brass peeking out from behind the back plate and didn't know what it was. Really didn't pay it much attention to it. Certainly wasn't obvious what it was for and given that it was deeply tucked inside the plates and it was very hard to get any kind of whole view of it. During the disassembly when I was removing the back plate, I inadvertently captured the mystery thingy in a shot. Let's call it the Seahorse. It's a brass piece that is riveted to that back plate. No removing it.  However it pivots freely on that rivet and has a very large pin sticking out perpendicular to the brass plate. The pin is really like a rod. You can see it protruding clearly 2 photos above. If you push that bottom round par...