What cuckoo clock is right for you?

People often approach me to buy cuckoo clocks and are quite surprised when I say I dont sell them, only repair them.

Thats not really a choice for me because despite my efforts to slow the earth and create a 30 hour day (where is Superman when you need him) I really dont have time to sell and fix. Selling clocks is….mostly administration. Its boring. I have no idea what the profit margins are and if I were to sell a cuckoo clock Im the sort of person who would start a cuckoo clock building company. I know exactly the sort of clocks I would make and they would be put together in a way that addresses the problems Ive seen with cuckoo clocks over the years. And heres the thing. Ive just realised I probably know more about cuckoo clock repairs than anyone else in the UK. You might think that the people who sold the clocks you can buy would be the same people that you would go to in order to service the clock every few years but people who sell cuckoo clocks generally dont have a clue on how to service them. Its a peculiar sector or the market because most clocks are bought on holiday and cant be taken back to the original source of purchase independent reapairers like myself take on this role.

Loestcher actually rung me and asked me to become their UK service Centre after seeming some of my blog posts about Antique cuckoo clock restorations. The older clocks are more complicated and we do those. Wooden cage movement clocks dating back to the mid Victorian period often make up a lot of what we do in any given month. I think the best one we have done so far is here…

Anyway this article isnt about bragging or emphasising a specialism, its about what I would think about if I was asked to recomment a cuckoo clock bought new from retail / online

Ive seen, I think, evey type of cuckoo clock made since 1850. Through that I have learned the evolution of this strange branch of Horology. Cuckoo clocks were the first clocks made more for looks than time keeping. You dont need a bird popping out every hour or half hour advising you of the time. You have a watch or a phone.

So cuckoo clocks are about fun. Its really is as simple as that. They are delightful for grandchildren to visit . Interestingly the two most connected things between cuckoo clocks (and their repair) is children, due to the fact that they get exited about the cuckoo coming out and will actually wait, on the hour, to see the bird come out and cuckoo. If the cuckoo doesn’t come out exactly on the hour a lot of children get impatient and try and encourage it by pulling the weigths shaped like pine cones (not exactly discouraging).

Because the clocks are mounted quite high on the wall to allow the chain to drop through 24 hours use, the children pull the chains.. This results in the clock either being wound up so that it jams because the chains are pulled to hard (stretches or breaks the chains), or the clock coming off the wall and smashing to bits (and I get sent a puzzle of bits). About 1 in 8 clocks are sent to us after a child has played “Tarzan” on the chains. What amazed me at first was that no child got injured but then it dawned on me that so see the cuckoo, if your only 2 to 4 feet high, means standing back so you can see the cuckoo door. It also means you are not directly in the path of the falling clock. Its got to the point where if a customer tells me the “clock just fell off the wall” I will ask if the grandchildren have visited recently.

Sorry I am going off at a tangent. I will now tell you about cuckoo clock types and why you should buy each dependent on budget and circumstance.

By far, the best cuckoo clock you can buy is a two weight (275g per weight) small cuckoo clock for up to £500. If you buy a 3 weight clock then it means its got a music box. If you put a music box in a craft clock built by a few people in a Bavarian shed then you can be pretty sure they have either guessed at the power requirement to drive two machines (the movement and the music box). You cant do the torque calculations that will lead you to the theoretical power required to keep the clock going and the music box every half hour. The gearing is not precise enough and the mechanics that lift a bar allowing the cuckoo to go off and then start the movement are pointless to calculate. There is too much variance in the hand building process. So what happens is that somebody designs a clock around standard components and their own styling and they build it. On day one it works find but then if they have cut costs by specifying a music box with a platic worm gear (for instance), while it all works on paper, after a few years it doesnt work. Repairing clocks with music boxes is twice the price of repairing one without.

If you want something a bit more exotic then there is a huge choice of various machines and makers. In terms of clock hierarchy there are three main brands. Loetscher, Huber Herr, and Schnieder. There are others of course but in terms of industry prescience I would say these are the top three. These companies produce some truely impressive machines with dancers, wood cutters, water wheels and moving animals. The only problem is that each of these features are driven bu the weights and Ive noticed some clock manufacturers balance the quantity of power to drive them, plus the power to keep the clock going, quite closely. This means that any reduction in efficientcy via fouling or dust build up stops the clock much more easily than the same amount of fouling on a much more cheaper and equally as fun cheaper two weight.

Servicing every seven to ten years on one of these big 3 weights is…heavy. £400 or so and many larger and more complex clocks have components that are out of production in a few years if he model doesnt sell well. This means paying more, much more, for a fix. Also as you can imagine, all this extra functionality comes at the additional cost – wear. Movement manufacturers, as a general rule, do not produce a movement specific to a power rating (the weight of your pine cone weights), so an arbor and plate thickness is designed to hold “an average” weight”.

Anything running more than 1kg weights will simply wear out more quickly. If the manufacturer cant provide spares then you have to effectively “re-purchase” half the mechanics once the clock is worn, generally after far less time than that of a 275g 2 weight cuckoo only based machine.

Up to 420g will give an average lifetime of 20 to 30 years whereas an unserviced big 1500g 3 weight clock is a third of that. My clock is about 140 years old, double fusee driven 8 day machine and I can tell you for a fact that if I did not love it more than anything else I own apart from my vintage watch (oh and my kids), I would not entertain it. Its too expensive to wear down. I dont run it – I just gloat over it.

The size of your clock is all about the size of our clock. Bigger clock, bigger cost. Such is life.

Hand forged / fired Glass Pocket Watch Glass job

The subject line says it all really, in that we had an expensive pocket watch in with broken glass. The glass was particularly thin and nothing “off the shelf” was ever going to fit. So we made our own.

We did this by cutting the glass blank with a ceramic lathe to exact diameter and then, having made a jigg, used a glass furnace to recreate the original convex curve. The end job is indistinguishable from the original although it is stronger, perfectly polished and a peffect fit.

The cost for this, including a very thorough service was under £1000 on a chiming gold pocket watch valued at around £7000. We are brilliant value for money and have equipment which others simply dont have. I genuinely believe that this job would have had to go to Switzerland for serveral times the cost and I doubt the job we made of it was not just incredibly cheap but also the best possible results in terms of quality finish, materials and strength.

I dont usually do bragging articles but the reason I am doing so on this occassion is that if you a have smashed special fit glass we can do it and we are one of very few organisations that do.

Brilliant job of which we are very proud.

Fusee Clocks – what and why

Ok I did an opinion article and I owe the blog a good tech article for the clock enthusiast.

Spring driven clocks are not accurate without a fusee movement. Thats a massive controvercial statement in clock terms. It means that your grannys 1960 mantle clock probably tells the times accurately twice a day. You dont notice because you get the time from your phone or your watch or the TV. But its true.

To qualify this I am making this statement only in the context of pendulum clocks with a short (say 6 inch max) pendulum. The almost direct opposite applies to long case clocks with long pendulums.

A pendlum clock can be simplified into three elements. 1. Power 2. Gearing 3. Regulation. This is the device that divides up time. It could be a pendulum or a balance wheel or a verge escapement or and atomic decay cycle etc. Notice that I have not included any category for hands and face because I clock does not have to show you its working to be accurate. Displays vary. Mostly they are dials but then you get barometric devices that output a line to a graph paper on a drum that rotates on a weekly basis. Its still a clock in essence.

Now, given that you have these three element the most important thing is that everything continues to whizz and whirr at EXACTLY the same rate. This is achieved with item 3, Regulation. Regulation in a pendulum clock is pereformed by…the pendulum.

A pendulum with a fixed centre of gravity will continue to swing at the same rate if no friction is applied. The friction is the bend in the spring at the top of the pendulum, the light touch on the crutch fork on each swing and air resistance. A pendulum of about 1 metre will swing at 1 second per swing. It will only slow down because of the friction wind/string/crutch friction. Forget the crutch thing – just consider wind and the bendyness of your pendulum as the things which cause friction.

Ok so you swing the pendulum with pallets. Describing this is going to be a challenge. So…

The spring is the power plant that turns/pushes the cogs leading up to the top of the clock. Its essentailly a mini engine connected to a gearbox of gears. By the time the spin has been passed from cog to cog – usually about 3 “wheels” (cogs) the last cog is spinning freely at hundreds of revolutions per minute vs the very slow crawl of the power plant at the start of the gearing down process.

So what you end up with is a turning wheel at the end of all that. The wheel is cut so that it looks rather like a cog but is nothing of the sort. Its rather like a cog but each tooth is a sharks fin. Theres a reason for that.

You see that top sharks tooth wheel is the thing that makes the pendulum swing. It does it by getting each tooth, in turn, to push a pallet. A pallet is a bit of flat metal connected pretty directly to the pendulum. So as the sharks teeth pass the pallet it nudges the pendulum one way and by the time the pendulum swings back it blocks the path of the pallet again and the process repeats.

Even if you didnt really understand that what may have occured to you is that the push from the sharks tooth has to be hard enough to counter the friction from from the air and spring friction.

If the sharks tooth is pushing hard enough the clock keeps going becuase the pendulum keeps swining, and if its stops then it means the pendulum is not being pushed hard enough by the pallets due to dirty gearing and no oil.

That was so hard to explain in a few paragraphs. If you didnt understand it then you may be suffering from “brain cavities”. I think I may have brain cavities because Ive just read it back and, bearing in mind I wrote it, I can barely understand it. Right. Whats a fussee.

I said your grannys clock isnt accurate. Then I explained how a clock works. The reason I did this is that if you get the first bit about a clock being a simple device to measure how many times a pendulum swings a minute, then the fusee is an easy extension of this.

The whole point of having a spring and a gearbox in a clock is to push just enough energy into the swing of a pendulum to counter the friction forces. Its a tiny amount of power to add to the each swing. Imagine swinging a your friend on a playground swing and keeping them going at the same rate by breathing in their direction. If you wanted to keep your friend swinging you just covid cough in her direction and off they would swing. Interestingly they would swing a bit further if you coughed hard and less so if you just coughed normally.

Now, a spring fully wound will cough harder than one at the end of its infection. This means that Newtons laws of physics are violated by the input of extra power to the system thereby creating an artificial, and therefore intrinsically innacurate method of regulation should the extra power going into the system reduce. Which it does.

The reason I just scientifically upped the stakes with my last sentence was that your so far through this that Im betting you will carry on….maybe. I will never know to be honest as Im too busy to check the website statistics which all appear to be in Greek – Its all Greek to me.

So the fusee is an ice cream cone shaped cotton reel, or larger. that acts as a variable ration gearbox in the cog sequence in which it is second. The first is the spring. The spring drum and the fusee ice cream cone are connected via a chain or wire which wraps around one or the other. If its wrapped round the spring drum the clock is unwound. If its wrapped in ever increasing diameter loops round the ice cream cone then the clock is fully wound.

[When the clock is fully wond it has a stop system inside that wil not allow you to move the key further. Its solid and distinctly different from the normal wind pressure. The reason its there is so that you dont give it the beans and snap the fusee wire – these clocks have and easy but long wind to accomodate the “gearing”.]

Fusee movement were invented……ages ago. I have to idea but Ive seen them on clocks to 1700 and I think 1690 (im not sure it – was an expensive bracket clock) so quite early on. I think the reason it did not become a standard feature were multiple

  1. Difficult to engineer the ice cream cone drum on which to wind the wire from the spring drum. This is not at easy bit to make. Firstly you have the problem that it cant be lathed without a lathe capable of operating from a copy or being programmed. Imagine having to make a perfectly accurate helter skelter from brass. In 1680. Evidence of Aliens as far as Im concerned.
  2. Maintenance. This system is more complicated. It has less set pieces you could stamp out of a sheet or cut with a jig. The implications of the string snapping on a full wind (which is obviously the point at which its most likely to snap) are slightly horrific. All the energy from a 55mm x .5. x 100mm spring releases into the clock putting immense recoil pressure on the first wheel. This means the gearing on the ice cream cone goes flat. You loose a tooth or two. This is SPECTACTULARLY expensive to get repaired. I wont do one. Affordably.
  3. Its all very well having these brilliant methods of transferring torque and mixing things up a bit to get what you need. It is. You see the majority of fusee clocks we see are not 17th century guilt portable chronometers (pffft – accurate to a minute a day if its working), they were school and station and company clocks. Utilitarian devices. They were designed simply, and oddly, to a build profile common to all manufacturers, and they HAD to show the right time clearly, hence the tendency for mid sized (12″ white face) to large clocks . You cant miss your train because the clock is worng. You cant be late for work and argue your clock is more accurate than your employers. These clocks, these municipal and railway and council office clocks are BRILLAINT. They say so much more about the leap of our society where you didnt turn up and 8.47am and leave at 5.25. You worked 9 to 5. Hard. The other delightful thing about them is that wood they used was not veneered. You get solid plank with varnish and polished. The simplicity of the external design and the high specification of hard wearing woods is fit for purpose, but of course we know the longer terms benefits now. Most have knock mark which shows its not from Marks and Spencer and there is even a key on some (“I wasnt late – look at the clock”). The star is of course the movement. The plate, pallets, arbours, bushes, the whole lot could have come out of a  Messerschmidt 109e (plane, ww2, sorry. It was awesome) for the build quality. They cost a sunken galleons treasure chest to restore mechanically but your cant repair good quality with bad quality. Well you can actually. Punch bush, flatten and reposition the escapment, polish the arbours. To do it properly you need a spring change and that bit is not fun. Its 55m of .5mm carbod steel held with alloy bendy wire that has to go into an aperture with 2mm tollerances, usually with some sweaty mods to the coil size with a spring winder. If it uncoils half way through Im Ok. Thats because I wear a full really expensive full leather apron, gloves fit for Apollo and one down from a welding mask.



Our Brilliant NHS Workers

We live in a country where healthcare is free to all. As we are all aware people who work in the NHS are all part of a big team put together to keep us alive and without the need to worry about huge medical bills as well as your illness.

Thats absolutely brilliant but the people who enable this system are underpaid for the risk they take to save your life.

We are due another stretch of covid variant and the nurses and hospital porters and surgeons are going to risk their lives to save somebody you know. How can you thank people for something like that. Also this time last year we were all outside clapping the NHS staff whereas now we seem to be taking it all for granted and see it as our own problem with the NHS less considered.

I cant cure a covid sufferer or even guess how to help with the medical side of things. What I CAN do is make the lives of those who put theirs on the line is offer my services at a 50% reduced rate.

So thats the new policy.

If you work for the NHS then you get a 50% discount on all labour charges up to £500 (I cant extend this to parts cost unfortunately).

Thank you to all NHS workers. What you do is really appreciated and courageous. I dont care if you work in the back office or do the laundry or your a surgeon – your all fine people and Ill happily work at a discounted rate for you because we know you love your clocks and we love you!.

There are some limits on how far I can go with this as I have to pay the bills too but Ill make your clock bills good deal easier to pay. If you could mention your NHS employed and send a pic of your NHS ID tag in your initial email then Ill make sure you pay a good deal less than…people who dont work for the NHS!. The other thing I can do for NHS employees is staged payments. Ill work on a 3 month staged payment plan if this makes your life easier. Thats what Im doing. Not exactly saving a bus load of nuns and kittens, but something at least.

You probably dont work for the NHS and are reading this purely because you read my blog. Have you thought about what you could do for NHS workers?. Its not something that immediately springs to mind when all we hear is bad news but Im sure there is something you can do for NHS workers somehow. I dont know what that might be or how you might implement it, however, these people do and will need our support. A donation to the NHS is laudible but does it get through to the people who do the work and take the risks?. Call me cynical, but I doubt it. If you can do something directly for an NHS employee I would say that its the way to go. that assumes you want to help and you can. If you dont and you cant then fair enough. Im not trying to change the world or judge anyone. I mean fine. You sit there with scantily clad maidens feeding your peeled grapes and then call an ambulance because you need your fingernails cut. Medically. And your not paying. I mean do you have to pay for everything. What are the overheads? Clippers I suppose. No, theres not judgement going on here.

Joking aside, if you know an NHS worker why not offer an open invitation to dinner once or twice a week so they don’t have to cook when they get home. It sounds odd and overly personal but thats how I grew up. There was more community. And how much time does a nurse or hospital porter get to mow the lawn or wash the car. I know it all sounds rather high minded and vaguely religious but when I grew up in the 70’s people were like this already. You knew your neighbours as friends. Things were just more socially integrated despite the absence of Facebook/Meta and computers. People did spend a long time on the phone mind you.

My point overall in offering an NHS discount is more about that sort of thing. Its got nothing to do with money from my point of view. Theres no publicity, no headline, just what I hope will become normality. Quite frankly it went wrong with the digital watch in my opinion. I was getting my first Timex Junior when the rich kids had red LED watches that lit up and told you the time in writing!. As an aside, Ive had three since, each of which has failed almost immediately and seems unrepairable but I still love them. Anyway, given that there is a chance of the NHS getting overwhelmed I believe its probably time to think about offering support, in whatever way, to those on the front lines.

I rarely do this type of article because who cares what I think. People want to know what I know about clocks and hear about interesting clock related things, however, there is a tenuous link in that Ive had a few NHS customers recently and the only reason they got their (prior) 25% discount was that I tend to get to know my customers to some degree and they obviously mention or refer to their work.

I cant become “Dr Clock” and just do NHS work so Ill have to limit it to a couple of clocks per month but that allowance should be more than adequate. If it goes over this estimate then Ill either cut the service and offer it to certain people on a face to face basis, or ill cut back the percentage or limit the financial elements in some way. Just a warning!.

Ill do a clock article now.

Christmas Opening Hours

I am shutting up shop for the holidays from 4 pm Saturday the the 18th of December. I will still be working but the workshop and the Saturday clock clinic wont be operating until the 8th of January 2022.

So, The workshop closes for xmas between 4pm Saturday the 18th December 2021 to 10am Wednesday the 5th January. The first clock clinic runs on the 8th – this is for simple low cost fixes and quotes / collections / deliveries and runs every Saturday normally.

I will be working at my home workshop during this time except for the 4 days of Christmas inclusive of the two bank holidays.

Most of the rest of the two weeks I will be available on the phone to book a a January call out or just offer a bit of advice e.g. a 3 minute phone call about how to set up your new cuckoo clock.

If you need me to come round for something urgent then just give me a ring. I cant promise any specific availability but I expect to be doing at least two call outs while the Antiques Centre is closed as is normally the case over the Christmas shut down.

My number is: 07462 269529

Email: admin@braintreeclockrepairs.co.uk

So, dont be afraid to ring. Things are happening and Christmas is just an inconvenience as far as I am concerned although the idea of working from home for a couple of weeks does appeal to me greatly!.

Have an excellent Christmas, be the best you can be and remember Christmas is about other people so get round and visit those who might me lonely or felt forgotten. Im 55 and Im lucky if I get 3 people visiting but then again, I live with my two sons so I always have company. Providing I can sabotage any girlfriend relationships they may attempt to engage in I should be able to have them around for quite a few more Christmases.

Reviews Technical Hitch

To my horror I saw this morning that the seventy 5 star reviews on google have dissappeared!. Im currently trying to sort out the issue with google but in the meantime if you wish to check my credentails or talk to an existing customer about their experience with our service please call me on 07462 269529

Victorian Cuckoo Restoration (Wooden Cage)

This is a job we recently completed. Its due to be ruturned tomorrow now that it has passed its 48 test run without incident.

These wooden cage movements are difficult. I would not recommend them as projects. The problem is that with their brilliance comes certain drabacks. Insect attack is not something most clock techinicians are used to dealing with; well maybe on the housing but not the movement. Right, STOP, picture before I proceed…

Cuckoo Clock Restoration
Completed restoration of a Black Forest Cuckoo clock with a wooden cage movement. Particularly diffuclt!

That better!. We can see what we are talking about now.

So what we actually have here is a wooden cage movement cuckoo 30 hour clock with a grape vine design for the facia. I suspect it may actually be French or more likely Swiss because of the use of fine wood throughout (probaby fruit tree – pear for the fascia and then the same for the parts of the housing that show).

The movement itself is oak. Im not sure if Ive evangelised about wooden cage movements before but they are actually very good in a “fit for purpose” way. Nobody is going to pretend such a device is going to provide chronometric time keeping but, actually, such machines can be brought witin a minute or two accuracy per day which is amazing considering the basic design.

Have a look a the following picutre.

Lets face it, when you or I or anybody else look at this they see two things. Firstly a wonder of technology an innovation, and secondly something that is unlikely to run for 10 minutes without the wheels flying off.

The fact of the matter is that using wood for the support and strutt contruction of the movement is entirely logical. Its lightweight, can be addressed with carpentry skills in an age where those skill were more common, and if there were any doubts about the longevity of such a solution this clock sets the record straight. This is of couse after a farily comprehensive service that was really more of a rebuild. Oddly, when its a rebuild its usually the metal components a that have worn or warped, not the wood.

As you can see from the picture new bellow tops have been fitted and some of the wiring replaced, but other than that the gearing and suchlike is completely original. This clock was 50 years old when the first model T ford rolled off the production line.

In this job we:

1 Stripped and cleaned and polished all connecting surfaces in the power train of the going and strike gearing.

2. Replaced / resoldered the crutch end which has been joined with glue as a temporary solution

3. Rebushed the necessary collets from the inside of the “plates”.

4. Rewired the cuckoo to allow the beak and wings to flare.

5. Set the door latch opening sequence

And all the normal stuff.

Its a great clock and I think I can honestly say that on a damage vs age graph this clock, of all the antique cuckoo clocks we have done, is in the best original condition. It runs brilliantly with a strong tick tock and positive energy pendulum swing. A pleasure to own I expect. Id happilly run this as my main time keeper for the house. Its accurate enough and has a very pleasant bass cuckoo sound achieved with long good quality pipes (the originals).

Junghans P18 b%”*&& problem

Ok so we had a nice c1900 Bracket clock in for a blank cheque resto. When you get an instruction like that, you pay attention. It means its got to be perfect; the money is secondary.

If I said to you “look, I hear you are good and thats what I need. Can you please return this cherished whatever to good working order”, if you are going to say “yes” you have to know you have the required experience to deliver. If you dont deliver then the client will come back again and again with problems. Returning clients with problems are a huge drain on just about every aspect of the business. My business. So, return jobs happen, but one of the key aspects of running a busy clock repair business is to know what a natural unit rate of return is.

1 in 5 is appalling. 1 in 10 is just what you have to deal with if your on a professional journey, and 1 in 20 is background and what to expect if you have machinery, knowledge and experience. Of those 1 in 20, for the vast majority of the time, the problem is a person not understanding how to run a weekly clock and the key “do’s and don’ts”. So basically if your going to do this job you either do it with everything you expect you will need in a worst case scenario, or save yourself a nervous breakdown.

So, on to the close nervous breakdown. That is a bit dramatic but, you know, it bothered me. So I’ve just realised that the point of writing this article has little to do with a P18 movement and Arthurs clock although ill give you and abridged dialog.

Arthur has had two clocks reparied and restored by us. He lives 90 minutes drive away. He gave us a blank cheque order and we did a brilliant job on a difficult movement at half the price of our competitors. Arthur collected the clock and it ran brilliantly, but then one day it made a loud bang when he attempted to wind it.

The clock came back and we did a full strip down diagnostic and found no problem. A week later we found a small fragment of metal in the case. It was clearly recently departed from its parent. We realised we were looking at part of a key. Because the clock had been recently refurbed by us the strength of the springs increased. This meant that an already worn and rattling key fit, finally rounded off internally and failed to provide any purchase on the arbour.

Everyone brings their key when they bring their clock. We only take the clock and not the key. From now on we will test the key fit before declining the key and accepting the clock.

We think we know everything but we don’t. We will…eventually.

From the clients point of view the clock had failed in a major way, when the actuality of the situation was that the problem was not in the clock, but a worn key. We don’t take keys from clients and have our own, so we didn’t have an opportunity to check the fit and chance of it shearing. On this basis we charged the client around 10% of the original bill as it did cover a complete strip down to the heart/spring diagnosis. Had it been bad work on our part there would have been an apology and partial refund of 10%. We get through a lot of clocks and at a 1:20 return rate, a clock every month or two comes back, and in these situations a 10% refund is fair. Its not about the money and all customers end up being someone between friends and acquaintances on a varying balance scale.

Well, an article about fault diagnosis has turned into my own internal process analysis and Ive bored you to sleep probably. Read some of the other articles – they are good. In my opinion. I dont publish boring rubbish!.

Oh. I did. Sod it, pubish and be damned.

A few things we did this week

As a business owner that runs an operation where every single job is different in some way its often quite hard to describe to people what we actually do. “We repair clocks” covers a huge amount of different jobs each with its own associated or individual method. So, its getting to the end of the week and I thought it might be interesting for you to hear the jobs so far and what we did. The following snippets are obviously not the entirety of what has been completed, started, put on the shelf , or picked up again with a new method in mind, but it gives an idea of what we really do. Ok….

Tissot Automatic Mechanical Watch repair

Bob came in with his Tissot. An nice 70’s auto with a gradient fade face in light brown on a gold case with a light leather strap. I wore it for 3 days on test (the only real way which you will have proven in this snippet) and I became quite fond of it.

The reason we were doing this watch is that we had taken on a very strange and exotic movement on for repair, carried that out successfully, and so Bob was coming back with a “no hope” job he had given up on but thought he may now have found somebody up to the job. Actually this sounds rather big headed but its what happened so what am I supposed to write?.

Anyway this watch had been through two high street jewellers and each time had come back unfixed. It ran 20 minutes fast a day. I was confident we could do it so I said “no problem” and got it fixed. The crown gear inside was broken and needed replacing so we sorted that out first. The watch underwent its basic service operations and ran correctly. We charged Bob a very fair price as a returning customer, which he appreciated and ticked it off the list – job done. A week later I got a somewhat annoyed phone call. Now, Bob is a nice guy, and apart from wanting to nuke China, is not in the least confrontational but it was obvious from the tired tone of his report that he felt let down and not entirely by surprise. The watch was running 20 minutes fast.

No. No. No. We have never had a watch back. So I obviously agreed to have it looked at as early as he could get it to me and we did just that. At first we had assumed oil had drifted onto the hair spring through a lubrication error. If oil gets on a hair spring in enough quantity it can form a bridge between concentric passes which has the effect of, from a physics point of view, shortening the spring. A shorter spring will result in a faster oscillation of the balance wheel. The faster the balance wheel cycles the faster the watch will run so it was an obvious assumption to make about the fault.

When the watch was opened there was no oil anywhere it shouldnt have been. We then found that the hair spring was very very slightly warped and close to its platform. If a hiarspring touches its platform mounting while in motion is has exactly the same effect as the oil. It shortens the operating lenght of the spring leadying to a higher BPM (beats per minute). The spring was remounted to be as far as possible from its supporting platform edges and that made the difference. I wore the watch, as I said, for three days. During that time I was half expecting it to run fast for some reason. It didnt and kept perfect time. We also fixed the date wheel advancement which Bob had simply assumed was impossible to fix as the previous repair efforts had not managed that, or possibly even bothered testing it because that part wasn’t a difficult fix.

What was bugging me was “why?”. You see, the watch had been tested the first time and it was running perfectly. It was only when Bob put it on that it started gaining time. At first my thoughts were towards an error in the winding system or gearing but then I had a Eureka moment. Its not that I know this is what was wrong with the watch, its just that its the obvious reason when you think about it, and here it is. HEAT. Bobs body heat when he wore the watch was slighty heating up the carbon steel hair spring. If you deform a hair spring at the beginning of its wind length this warp is exaggerated exponentially by the length of the spring because you are warping along the length of the spring not the diameter of the coil. The spring at room temperature was almost touching the platforms and it was, as sods law dictates, close enough so that any change on its axial level / flatness would bring the end of the spiring in contact with the platform.

Ironically because the connect would have been right at the edge of the coil the watch would still keep running but, for the already stated reason, run slightly fast. If the contact had been in the centre of the coil the watch probably wouldn’t have run and the problem discovered by the other two jewellers, but because I wore the watch I found the problem. Retrospectively of course but that doesnt matter. What is important is that next time it happens we know. Experience like that is money in the bank and better better better. I love better.

Cuckoo Clock previously repaired by a mathematician not an engineer.

Ok so another job this week worthy of mention was a simple two weight cuckoo clock that came in. The owner wanted the clock working but had a limited budget. I explained the pricing policy and range, how we could avoid certain costs, and what may become essential in order to complete the job. On occasions like this I take a bit of a commercial risk. I could see the movement was not standard in many ways, and worse than that there was no obvious reason why the clock should not run. I checked the connecting faces of all the wheel teeth and pinion gears with everything looking in great condition for a 50 year old clock. The bushes were nice and unworn, the gearing mostly clear of fouling, and the pallets in good order. I cleaned the clock on a full disassembly as my thinking was that with such a good condition fit for the bushes it must be oxidation on the inner bush walls. On cleaing and lubrication the clock turned over….but not…right. There is no real way of measuring how much torque an escapement cog is generating, its something you get a feel for after working on a lot of different movements. You recognise a healthy movement in the same way you might an animal. You can just tell, if you know what to look for, that you have a grand national winner or a beach donkey. This one was wearing a red had and carrying a small child jamming an ice cream in its face. So what could the problem be….I had to put this down for a day. I realised during the night what the problem was. The bushes were brilliant. For a 50 year old clock they were immacuate. Too immaculate. Too unworn.

I went in the next day an hour early just because I wanted to check out my theory. I was correct. The clock had been “b*&*^ered about with” by somebody playing “lets try and bush a clock”. It was a bad repair performed years earlier so the patination of the new parts had faded and was undetectable. When you fit a bush for the first time the target is to get a nice snug fit with the current pinion diameter that has worn down on the old bushes. You can overdo this. If you don’t know what sort of torque you should be seeing at the escapement end its going to be very easy to bush a clock so that the fit is a little too snug and doesn’t give the pinion any room for manoeuvre. It needs to have a bit of play in it because you are fitting a bush to a slightly worn pinion gear and wheel. This means the rotation forces are not directly central as when the wheel and pinion gear connect the can move closer and further away from each other during the rotation cycle. This means two things. Tight bushing of this type leads to a cyclic partial seizure in the rotation cycle. In short, the gears are pushed closer and further apart during the cycle. This normally manifests itself as stiffness or partial seizure during each turn at the same point, or at the same frequency depending on the ratio of the gearing. This wasn’t what was happening so I hadn’t spotted it. What had happened was that the pinion gears and wheels were in unworn condition but the clock was simply bushed two tightly on the second wheel. I started at the top and broached the bushes by a fraction of a fraction of a mm and it worked perfectly. Clock repairs are like this a lot of the time. The process of diagnosis is absolutely critical so its important to use methods that explore the configuration, lubrication, and cleaning of components before you create one brass filing. One mistake I made when I first started was that I was too keen and in too much of a hurry generally. I have learned over the years that you have to be focussed and confident with what you are doing. That confidence only comes from success which is the product of method. So before you do anything on a clock work out how you are gong to do it. Allow time for the things you MUST get right first time and if your frustrated with a diagnosis then admit defeat for the day and the high ground will come to you tomorrow. Your brain is working all the time and so if you have a logic problem you will often find the old grey matter will deliver given time and your then running down the street in a towel like Archimedes.

The secret is caring. If you don’t care you wont think about it. Incidentally, care is not the same thing as worry. Its easy to mistake one for the other if its a friends clock you are working on. If you find yourself getting out of your depth and are actually worried then just stop, give the job back, retire and regroup. You cant do that if youve physically changed the shape of any metal in any way which is why its important to understand what a big step it is on a job to make changes you cant come back from or get support on if you need it. Incidentally if you are reading this with your mother in laws clock in 200 bits that somebody “cleared up for you”, rather than divorce, ring me. Its cheaper. Marginally.

(A joke to far – our prices our excellent).

Thats one day of man hours. Quite a few. Clocking is not a fixed hours occupation if your doing other peoples cherished family heirlooms.

Ok. Had enough. Off to bed.

How to build a clock

A lot of the jobs I do rely on two basic things. Firtstly I’m an engineer. I love understanding physics and systems. Secondly I love antiques and history and antiques so every time I see a broken clock I see a broken piece of history. History is history. There isnt old history and new history there is just history. So I fix clocks from any era. This balances well with my love of engineering because clocks encompass history as a constant variable. How we measure time. How we understand time. How we, as innovative human beings, are pressed by a compulsion to improve what we do. Some people believe this is primarily driven by capitalism and the edict of building a better mouse trap, but I believe it is something far more than that. We just like buggering around with things to make them “better” which is an entirely relitavistic word and concept. We promote entropy, the driving forward force of the universe, and just love making things more complicated to improve performance.

But you can over do it.

Clocks really really demonstrate this because in the rush to develop ever more accurate, portable and miniaturised time keeping systems we have made mechanial clocks far more complicated than they need to be in order to do exactly the same job.

So whats the simplist effective way of making a clock?

Its fairly straight forward and you can do it with wood, metal, or reclaimed materials.

A clock comprises of three essentail systems that link in a linear format. These are

  1. Power
  2. Gearing
  3. Regulation

Thats all you need. Its really as simple as that. Lets explore each

  1. Power. Clocks are either driven by springs or weights. Weights are better. This is because they supply a constant force. A hanging weight always weighs the same at the end of a string, not matter how long the string is. So if you base your power source on a weight then you know that the force going through your gearing is going to be constant. That means the rusult will be constant. The results in this case are the rate at which you minute hand goes round 360 degress in an hour. You dont really want that calculation to have variablility within its cycle. So you get a barrel with a cog on the end of it, wrap a string round it, and then hang your weight from the barrel. The turning force of that barrel with the weight hung off it will always be constant. Because you included the cog on the end of the barrel you have a method of transferring that turning power (torque). Torque is measured in foot pounds or newton meters. Imperial and metric. Imagine you have a car wheel. You weld a metal bar that is 1m long to the centre nut so it sticks out like an arm from the centre of the wheel. You then hang a 1kg bag of sugar off the end of the welded rod. You have created a turning force of 10 newton meters. Im not going to bother with an explanation of how newtons are force and KG is mass. Its the same as far as we are concerned in this article. My point is that the force you transmit up a gear train from the source is calculable quite easily. If you hang a 1kg weight from a 1m radius barrel then you are generating 10 newton meters of torque (there are about 10 newtons to a kg). Im probably going to far with the maths here as this is a concept article.
  2. Gearing. The reason you need gearing is to spread out the drop of your weight so your clock doesnt work for 10 minutes before the weight his the floor. Its to slow down the rotation of your barrel with the weight on. Each spindle in a clock has a wheel and a pinion gear. The pinion gear has a set fraction of teeth compared to the wheel mounted on he same spindle. Its a ratio converter for your torque. So you know from “power” what your output is but now you want to divide that up into smaller chunks of power per second. You therefore gear down via connecting pinions and wheels in a sequence until the last cog in your gearing turns quite quickly but with very little force. The last cog in the gearbox is called the “ESCAPEMENT”. This is where the pedal hits the metal and power is transferred to the regulator.
  3. The regulator. The regulator is the part of the clock that actually measures out time into consistent units. The idea is to make one, or an exact division of these units, equal to one second. There are three common types. Quartz crystals that vibrate at a very specific and exact frequency when an electrical current is passed through them, platform escapements where a cartwheel on an axle rotates back and forth because theres a spring attached to it, and a pendulum. A pendulum is the best. A pendulum always swings at the same speed in a vacuum. That means that if you start the pendulum with a big arc or a small arc is will always pass the “down” centre point with the same frequency. Thank Newton (Issac not the unit) and Huygens the astronomer for that. This means that if you put a device on your escapement cog that allows each cog tooth to push the pendulum just enough to account for air resistance then your escapment cog is going to turn at whatver rate the pendulum passes the down centre point. The device that does this is called an anchor escapement. Imagine an upside down anchor hanging over the escapement cog. The pendulum attaches to the shaft of the anchor and the anchor points are set low enough so that when the pendulum is at rest the points sit in-between the escapement cog teeth and prevent it from going round. I wants to go round and is applying force to do so, but not enough to start the heavy pendulum off. If you swing the pendulum then one anchor point goes up and the other goes down. The one that goes down connects with the side of the cog tooth thats trying to turn and the force is transferred to the pendulum. As the pendulum swings to the other side of the anchor comes down in between the escapement teeth and the process of force transmission continues in this repeating cycle.

If you change the length of the pendulum you will find the point at which it swings back and forth at 1 second. If you escapement cog has 60 teeth then bingo (each swing is one second, left or right). That sorts the seconds and minutes out so an hour hand just needs to be put on with an offset cog at a 1:60 ratio. Easy really.

If you have understood this you’ve just made a clock. The actual production is just detail.

Incidentally all this is really down to Newton and Huygens. Every few generations has their greats and if you want to know who ours is its Elon Musk. We are privileged to live in his lifetime and I highly recommend you follow what he is doing, how he does it, and how he thinks. A new type of genius for a new age.