Calibrating your wooden clock

  We all know by now that adjusting your new clock build to tell the right time means moving the weight on the bottom of the Pendulum either up or down to make it run faster or slower. I have always done this manually over a few days, gradually making finer and finer adjustments until a satisfactory accuracy is achieved. I have never achieved better than 20 seconds a day deviation because environmental factors seem to affect the accuracy, so striving for better is usually a waste of effort as it can be changed by the next day.
 The picture on the left shows the back of a new Clock I am working on with the Pendulum weight, in this case, a Brass cylinder supported on a thin disk at the bottom that is a friction fit on the Pendulum rod. The clock rate is adjusted by moving this disk up slightly to make the clock run Faster or down to make it run Slower, the more you move it in either direction the more its rate will change.

Recently, however, I realized that I could use an app on my phone or my iPad to help with this and cut the days down to minutes. These apps use the microphone on the phone or iPad to listen to the clocks ticking and from that calculate the rate at which it is running.

The first of these I used was 'Cuckoo Clock Calibration' on my iPad.In this case, with the new clock, there is a predominant single tic because of the nature of the driving mechanism, so we are looking for BPM of
60 which you can see here is very nearly achieved.

In this second case, I used my Android phone with the 'Clock Tuner' app and again 60 BPM.

In both cases, the apps themselves are capable of much more but we simply need to know the BPM so that we can adjust the rate of the pendulum swing by moving the weight up or down to zero in on the 60 beats per minute. The technique, therefore, is to take a reading, adjust , take another reading until such a time as you can see no improvement.