How These Clocks Work

Clock Clock Clock Hour Hand Minute Hand

These are weight driven, pendulum regulated clocks.

The driving weight drags on a cord which passes round the drive arbour, this causes the largest wheel (the 'great wheel') to rotate as the weight slowly descends. This wheel meshes with the pinion on the intermediate wheel, causing it to rotate faster in the other direction. This wheel in turn meshes with the escape wheel pinion, causing it to rotate even faster, in the same direction as the great wheel. These three wheels are together known as the Going Train. If the escape wheel were allowed to freely rotate it would spin very fast and the driving weight would descend fully in less than a minute.

Mounted to the rear of the clock is a pendulum, swinging with a very regular and predictable beat. The clocks escapement (the combination of the uppermost wheel and the rocking anchor) connects the pendulum to the going train - the rotation of the escape wheel is now precisely controlled by the swing of the pendulum. The gearing of the going train is arranged so that, with this length of pendulum, the great wheel revolves once an hour.

The beauty of the escapement is that it does two jobs at the same time: as well as regulating the speed of the going train it also delivers power to the pendulum to keep it swinging. Each time an escape wheel tooth is released a little push is given to the anchor - first in one direction, then the other; these impulses are just enough to overcome frictional losses and keep the pendulum swinging.

The great wheel is mounted on the main arbour (the central shaft the wheel rotates around), which revolves once an hour - the clocks minute hand is fixed to the far end of the main arbour. The small set of gears mounted to the front of the clock (called the 'motion work') causes the hour hand to be dragged round at 1/12th of the speed of the main arbour. In my design there is a frictional clutch built into one of the motion work wheels - if a nubbin is pushed in the motion work is disengaged from the main arbour, allowing said nubbin to be turned freely - this rotates the hands and allows the correct time to be set.

I have designed my clocks to run for thirty hours when fully wound - they therefore need to be wound daily (though not necessarily at the same time each day). The clock is wound by placing a thumb in the central hole of the counterweight and pulling down - the drive weight rises until it is stopped by the bottom of the clock frame. A ratchet is used to allow the drive arbour to rotate backwards while this happens without causing the whole clock to reverse. The pendulum swings freely during the winding (an unfortunate additional effect is that the clock movement reverses during winding); power is restored to the clock when the counterweight is released.


The clocks ability to tell the time is governed by the length of the pendulum rod alone. Sophisticated designs have been produced over the years that compensate for the thermal expansion of the materials used in the rod, in my arrogance have chosen to use a material that changes shape with humidity as well as temperature. It is possible that I will offer a compensating pendulum in the future but I confess I see no real need of it in a world of cheap quartz, radio and atomic clocks.

The timekeeping of my clocks can be finely adjusted by raising or lowering the pendulum bob (by turning the bob-nut); in this way the clock can be adjusted to keep time to within a few seconds per day. This will drift over time as the seasons change, however. Central heating, air conditioning and de-humidifiers will all affect timekeeping. I expect the clocks would be able to keep very good time in the long term if kept in a stable climate-controlled environment.

I have not undertaken a detailed investigation into the timekeeping of these clocks - I think I'll leave that to the clock owners. I would love to receive feedback about any observations you make on your clock. In the workshop I generally adjust the clocks to 'close enough', and move the hands the few minutes that accumulate over a week or so. I have produced an excel spreadsheet that takes the error over a certain period and outputs instructions for how far to rotate the bob-nut, a polished version of this will be available to download at some point. I must say, I enjoy hearing how accurate my clocks can be.


Ah, the big one. I have designed these clocks with long term reliability in mind. I hope they will run trouble-free for many years, decades even. I'd like you to give yours to your grandchildren.

At the time of writing, Clock 10.01 has run for over three years. Clock 8 and Clock 9 ran for similar periods before being put into storage. Clocks 10.02 and 10.04 have run for about 2 years apiece while Clock 10.03 is just trouble. Both clocks in Series 11 have run well for a year, Series 12 clocks have run for months each. It is noticable that my recent clocks are easier to get working and work more energetically than earlier ones. I should state, however, that I accept some long term issues may yet arise. These are young clock designs - I'm sure I have much to learn about them yet. As a general precaution, I'm unwilling to let a clock leave my workshop until it has run for a significant time (in the order of several months with Clocks 12+).

I must say, though, that these clocks can stop randomly for no apparent reason. This is rare, and usually just needs the pendulum to be swung to re-start. I put this phenomenon down to draughts, sudden temperature changes and random quantum fluctuations in the structure of matter. The user manual you will receive with your purchase goes into greater detail about how to get a reluctant clock to run again, and what to do if it doesn't.

I fully intend these clocks to survive me. A wise-woman friend of mine has brewed incantations that are said over my clocks to guard against them 'stopping short, never to go again' when I do shuffle off; I'm delighted to say that I'll never know if this works. As a backup I intend to leave full documentation of each clock sold so any competent clock repairer can service them in the centuries to come.

These clocks require maintenance. Yours should be returned to my workshop after running for four years - I will dismantle and inspect it fully, clean all parts, replace any worn items and re-oil the bearing surfaces. I levy a nominal charge for this service. I think it is reasonable of me to offer a lifetime guarantee with my clocks covering my design, craftsmanship and materials. Sadly I will need to charge if a clock is damaged, but I will repair and possibly modify any clock that just stops working for free.