Escapement

In our last episode your local horologist was frustrated in his efforts to diagnose the movement of the  Vienna single weight regulator without the ability to mount the movement and pendulum in a stand. The Viennas are one of the few models of clocks where the pendulum is attached to the back board of the case and does not hang from the movement itself. And the way the pendulum engages with the movement is...  Hmm...  On a practical level it is easier for your correspondent (and photo essayist) to explain how this engagement occurs by taking advantage of the decoupling of movement, pendulum and case required for this testing effort. So... Here is the movement freshly removed from the case. The dial is still attached. Those slats slide into the mounting bracket in the case. Note the crutch descending from the top of the movement -- it has a pin attached to a mechanism at the bottom.  Here's a close up. That pin protrudes perpendicularly from the end of the crutch. ...

Persistence. It's a virtue. About six months ago your local horologist wrote a series of posts about a Vienna regulator as seen here , here , here and most recently  here . We explored adjustable deadbeats, the Biedermeier design aesthetic and the entertaining conundrum of the second hand that swept a full trip around its dial in 45 seconds.  And the clock doc did get our European friend to run. But not well. Here she is. Sadly, its pendulum swing was... anemic.  The pendulum had low amplitude (distance of the swing). So what does that imply you ask? The amplitude of the pendulum reflects the amount of power being transmitted to it. Not enough power and a clock will stop. And that's what happened with our Vienna. Let's step back. How do we evaluate the amplitude of the pendulum and what's good vs. not so good? To start it's not strictly how far left and right the pendulum swings. It's more nuanced. Some pendulums need big swings and others less so.  It's ab...

(Yes it's a spelling error in service of a terrible pun.) Your local horologist grew up on Monty Python.  In our last episode we examined the ailing innards of Chip's gravity clock which revealed some problems with the pin pallet escapement. As shown in this earlier photo the two principle issues were that one anchor pin was missing entirely and the other was badly mispositioned.  So the pin repairs were obvious but trickier than immediately apparent. Several complicating factors: The pins in the pin pallet escapement need to be made of steel to reduce wear and to engage properly with the teeth of the brass escape wheel (EW).  The pins need to extend about 2.5mm from the base of the anchor plate to their tip to in order to be long enough to engage with the EW teeth but not rub up against the wheel at the base of the crutch.  The pins need to be fairly specific in diameter; in our case about 0.37mm. There is room for a bit of play so something in the range of 0...