It will become blinding obvious pretty soon that my objective is not to attempt to compete with the Modern Harrison’s of this world, I simply do not have the engineering skills.
What I will attempt to do is to show you that the only person that you need to satisfy is yourself and that designs can be changed, I am doing it all the time. I can do this because I am not operating to somebody else’s plan but rather to an evolving idea that springs from my own mind. It is terrific really because you are never wrong.
So my advice is that if you wish to have a really accurate time piece, go and buy one of the Atomic clocks that are now for sale, or simply rely on your phone or computer. But if you want to build something that will keep you entertained for years, read on.
Why I Build Clocks
Clock making is a hobby that tends to attract engineers and scientists or people with a similar background. While there are a number of people who are doing what I describe as new and novel work, you will generally find that the option chosen by many is to duplicate an old and proven design and some of the work they are doing is outstanding.
I do not have those skills and with a background as a wood turner I like to cobble stuff together and see what happens. The result is not necessarily horologically sound but does provide me with a challenge that is likely to last a life time. Quite a number of my clocks have been modified and then modified again as I find a better way of doing what I did previously.
My objective is not to create an item for a market but simply to keep me entertained, frustrated and challenged. It is not easy to design a clock because you have to quite literally come up with unique ways of doing things by yourself. But provided you are prepared to accept the fact that there will be uncounted failures along the way the successes make it all worthwhile.
Where To Start
A good place to start any clock making endeavor is to develop at least some level of understanding of how a clock actually hangs together. I often liken my own clock making activities to those of a back yard mechanic whose theoretical understanding is sufficient to meet his own needs but who is on a continual learning curve and is constantly upgrading is skills.
If you never buy any other books, try to get your hands on a copy of Practical Clock Repairing by Donald De Carle. The last time I looked they were out of print, (my copy was written in 1951) but you can often find them on second hand book sites on the net. While I have never been interested in repairing clocks, this book has proved to be invaluable. If, for example, you decide to try your hand at designing a clock, on page 59 you will find a table “Clock Trains With Length Of Pendulum”. I used this table to select trains for all my clocks.
Before the digital age clocks were basically divided into three categories. Weight driven, spring driven or electrically driven. With the first two categories the movement is under continuous tension which is relieved by the a very clever mechanism known as an escapement. The escapement allows the tension to be released at a predetermined rate controlled by a pendulum and the more accurate the tension release the more accurate the clock .
The movement in an electrically driven clock is not under tension and this is what appeals to me. It can be driven by a number of electrical devices from coils to electric motors. I chose to use an electromagnetic coil.
I don’t want to try to be overly proscriptive but you could do a lot worse than starting with the designs Brian Law makes available. As you study his plans it will become obvious that it really is practical for an ordinary person to make a clock.
Why I chose to build electric clocks.
When I finished my first clock getting to actually go was very tense time. Initially it would only go for a minutes or two and as I fiddled and adjusted that increased to a few minutes and when that stretched to an hour or so, I was dancing around my workshop absolutely convinced I was a genius. The best I ever did with this first clock was sufficient time for the weight to reach the floor, when naturally it stopped. My decision to “go electric” is a very sad one that was born out of desperation.
As I have already said, the movement in a clock driven by a weight or spring is under continuous tension. By now I realised that my first clock was never going to be much more than a conversation piece so I decided to mount it in the hallway to our home. One day Christine (my wife) and I were having a cup of afternoon tea when there was a terrible noise in the hallway. We rushed to see what the noise was we were greeted by the sight of my conversation piece lying on the floor surrounded by a significant amount of gyprock and bits of wall framing timber.
The stainless steel wire that held the 7 pound weight was wrapped around a wooden reel and held in place by a wooden pawl. Apparently the wooden pawl had “let go” and the weight was free to do what gravity required and head for the floor. Unfortunately the steel wire was not quite long enough to allow the 7 pound timber encased lead weight to reach the floor, it was about 10mm too short. There must have been a pretty significant level of force by the time it actually reached the floor as evidenced by the damage it did to the wall.
So that was that. My brief stint as a clock maker had come to an ignominious end .I took my conversation piece to my workshop, threw it in the corner, repaired the wall and decided to return to making less dangerous stuff on my lathe. What I did not realise is there is actually an obsessive compulsive disease you can catch when you start to make clocks and I had caught it. Within a very short time, despite the fact that my knowledge of electronics was on about the same level as my knowledge of rocket science, I began to wonder how you made a clock go electronically instead of with a weight.