English Regulator Grandfather Clock with Dead Beat Escapement
designed by John Wilding MBHI
built 2013 - 2016 by Michael Adler
Building a precision Grandfather Clock.
My main hobby throughout my life has been building with Meccano. I have a large selection of re-usable gears, shafts, bearings, strips and girders and with them table top engineering is possible. Any structure or mechanism can be built including clocks, and around the world, expert Meccano builders do wonderful things.
What would happen though if I attempted to build something with metal from scratch, using a lathe and a drilling machine? This idea must have been formed many years ago when I did a technology course at the Cape Technical College in Cape Town. I produced a centre punch used for making a mark in a sheet of metal. The key moment came 30 years later when my family moved to an apartment where there was a small enclosed space on the balcony which could be turned into a workshop. This set my mind working on the possibility of acquiring a workbench and few machines and perhaps attempting to make something in metal like a clock. I ordered a very small lathe and a drilling machine, and a few essential hand tools and associated equipment. I also ordered a set of plans for a very simple electro-mechanical clock.
In the workshop
I developed an interest in clocks after a very special visit to the Royal Observatory Greenwich, where I saw the John Harrison marine navigation clocks working for the first time. It was Harrison who won the Longitude Prize in 1760 for his work on inventing a clock that could tell the time accurately at sea, desperately needed for accurate navigation and to save countless lives. I wondered then if I could build some of his mechanisms in Meccano, and succeeded with a grasshopper escapement long case clock. My interest in clocks was confirmed and I went on to build twelve more in Meccano and even published a book on the subject. Along the way, I became a member of the British Horological Institute, receiving their monthly magazine, and visited Upton Villa, their headquarters, where they have an excellent museum. I found that I had learned to converse with horologists. I hoped to attend one of the BHI course in clock making.
Clock plates and pendulum crutch
One of my Meccano clocks attracted the attention of a member of the BHI and he wrote to me about it. After some correspondence, I went to see him and we became firm friends. One of the rooms in his house was given over exclusively to a wonderful workshop, one in which he produced exquisite clocks and a few of them were working in his lounge and study. The workmanship was extraordinary.
An idea jumped into my head – would it be possible to learn some clock making techniques in his workshop? When I asked him and suggested visiting him over a four day period, he agreed, and so a long relationship over the next three years began. During those four days, I learned to use the lathe and how to measure accurately to a thousandth of an inch. We discussed which kind of clock would be practical to make and we consulted John Wilding’s list of clocks which were extensively detailed. In the end we settled on a precision Graham dead beat escapement long case clock. When I went home, I opened my dormant workshop for the first time, and bought the metal that I knew would be needed - brass plates and rods as well as a few special tools. In this way, bit by bit, my clock became a reality. I visited my friend a number of times, and during each of these sessions there were intense discussions about the clock and how to overcome problems. During one of those visits, I discovered that my teacher was himself building the same clock.
The day came when my clock was complete. After three years of intense hard work, I could see my clock gleaming in the half light, challenging me to start it up. With the help of a friend, we bolted the back supporting plate to a wall in my study and hung the heavy pendulum in place. When I placed the mechanism in front of it, I could not bring myself to see if it would work, and hesitated to start it for two whole days. I went for a long walk and came home to look at it. It was a huge act of faith to have laboured for so long on something so uncertain.
The moment had come and I could delay no longer. I gently set the pendulum in motion and put some pressure on the winding drum. I could see immediately that it was going to function as the clock ticked a few times. I went for a walk again, had a stiff drink and thought about the next steps. What was needed was an adequate driving weight in place of my finger. I loaded the cylinder weight with lead sinkers and started the pendulum oscillating. My teacher had told me that I would know when the weight was enough by listening to the action of the escapement, and he was so right. The clock has not stopped since that moment, and the most extraordinary thing is that it keeps almost perfect time.
It has been an exciting and a testing time for me. After all three whole years in the latter part of my life is no mean investment. During that time I have sadly neglected my normal Meccano activities.
The clock now has a purpose built case with glass door and looks very professional. A year ago, when most of the clock was complete, I invited a few friends who I knew might be interested to have coffee with me, and I showed them my work and some of the techniques I had used to make the parts. Having now completed the clock, and seeing it tick reliably, I again invited my friends to view the completed clock. I feel an enormous sense of relief that the project is over. I would not be able to devote so much time to such a demanding project in the future. But I am sure that if I had to start another such project, the time needed to complete it would be very much shorter as I have learned so much about precision workshop technology. It was in my little workshop that I experienced real peace. Always a challenge, I made many mistakes, and there were many frustrations. I suffered from lack of knowledge and from a reliable source of supply of materials and equipment and also of knowledge. I am grateful to my Hereford friend (whose own clock is now also working) for helping me to see the project through to completion, and I am grateful also to John Wilding whose detailed instructions were a source of so much pleasure. I now view my workshop as a welcoming place, and have already augmented my Meccano parts with and modified others.
My grandfather clock is ticking gently beside me. It gains a few seconds a day and this needs to be corrected. I will add a small tray to the pendulum rod and add very small weights to it to bring it to accurate time.
Gear train of the clock
Grinding the pallets on the Taig Lathe
My clock has some very special features. The pendulum rod is built from a metal called Invar. This metal does not expand or contract with changes of temperature, thus making the clock more accurate as a time keeper. Another important feature is what happens to the clock when it is being wound. After all it is the three kilogram weight that keeps it going. It has what is known as a Maintaining Power, designed by John Harrison. I am pleased that my clock has a feature which links it the original Greenwich clocks. There are in fact three gears on the winding shaft. One is the click which is heard when the drum is wound, another is a ratchet wheel to prevent reverse rotation, and a third which transmits power to the going train of gears. There is a spring between the latter two which keeps the clock going while it being wound. An amazing invention by a brilliant mind. The third clock feature is the escapement, called the dead beat escapement. There is no recoil of the escape wheel at each beat, and therefore no loss of energy in the power train. It is therefore more efficient, but I have to say, much harder to make.
My next Meccano project awaits. I have learned now that Meccano is the ideal table top engineering product for quickly making almost any mechanism or structure. It is a very clever trade-off between fine engineering and practicality.