Anyone unpacking a cuckoo clock for the first time is surprised at the same point: the weights are heavier than they look. On an 8 day model you are holding up to one and a half kilograms in your hand, and on a clock with a music box three of them hang side by side.
This is neither a coincidence nor a question of looks. The mass of these pine cones is a calculated figure, and it cannot be changed freely in either direction.
The weight is the engine
A mechanical cuckoo clock has no battery and no spring. All of its energy comes from a mass slowly sinking downwards. When you pull the chain, you raise the weight and charge the clock. It then releases that energy again over hours or days.
How much energy is available depends on two numbers: how heavy the weight is and how far it can fall. Everything else follows from that. What the movement does with it is described in How does a cuckoo clock work?
Every weight has a job
Two or three weights hang side by side, and they do not work together. The first drives the time train, that is, the hands. The second drives the strike train, that is, the cuckoo call, the door and the bird. On music clocks a third drives the music box and with it the figures that move on the hour.
Good news for everyday use: on our clocks all the weights of a given clock are the same. So you cannot mix them up when hanging them, and there is no order to remember.
The numbers
On our clocks it typically looks like this:
- 1 day movement: around 275 grams per weight, running time about 30 hours.
- 8 day movement: depending on the model 1,260 or 1,500 grams per weight, running time about 190 hours.
- Electronic models: no weights, batteries instead.
The jump by a factor of five is the price of a week of running time. Which movement makes sense when is covered in 1 day or 8 day movement?
Why not lighter
A clock movement has friction. Every wheel runs in a bearing, every chain over a chain wheel, the escapement engages a toothed wheel with every swing of the pendulum. That friction has to be overcome before anything happens at all.
If the weight is too light, the clock stops as soon as resistance increases, for instance when the oil ages or dust settles in the movement. It will then often still run with a freshly wound weight and stop towards the end of the day. That is one of the most common symptoms described to us, and in some cases there is simply a weight from another clock on the chain.
Why not heavier
A weight that is too heavy does not make the clock more reliable, it breaks it sooner. All the surplus force goes into the bearings, the chain wheels and the tooth flanks. The movement keeps running at first but wears noticeably faster, and after a few years what would have been a cleaning becomes a case for spare parts.
So never improvise. If a weight is missing, you need the correct one and not a substitute object of similar mass. The right specifications for your model are in the instruction manuals, and replacements are available through our repair service.
Why the pine cones are metal
The weights look like pine cones but they are made of metal. There is no other way: a wooden cone of that size weighs less than a hundred grams and would not get any clock movement going.
The pine cone shape is therefore pure design, the material is engineering. Together they are one of the motifs by which a Black Forest clock can be recognised immediately.
How much room the weights need
The energy lies not only in the mass but also in the distance of the drop. A movement meant to run for eight days therefore needs a wall on which the weight can sink for eight days.
As a guide: at least around 60 cm of free height below the case for a 1 day movement, considerably more for an 8 day movement. If you want to hang the clock above a sideboard or a sofa, measure first. And include the mass when fixing it: a large chalet clock weighs more than ten kilograms with its weights and belongs on a wall plug and a screw, not on a nail in plasterboard.
If a weight is missing
Because all the weights of a clock are the same, nothing can get muddled when hanging it. It only becomes critical when a weight has gone missing and is replaced by one from elsewhere, for instance on an inherited clock. The mass is then wrong, and the clock runs unreliably or wears faster.
If your clock stops, however, a wrong weight is rarely the first cause. The more frequent points are listed in Hanging and setting a cuckoo clock.
Two habits worth remembering
When winding, always pull on the free side of the chain, never push the weight upwards. Lifting the weight takes the tension off the chain, and it can jump out of the chain wheel. That is the most common avoidable damage there is.
Always take the weights off for transport and wrap them individually. One and a half kilograms banging around inside a box will destroy any trim strip in their way. How a cuckoo clock is packed properly is described in Having a cuckoo clock repaired.
In short
The weights are heavy because they are the engine of the clock, and they are exactly as heavy as the movement needs them to be. Too light and it stops, too heavy and it wears. Use the weights that belong to your model, allow for the drop, pull on the chain and not on the cone. There is nothing you can mix up along the way.
Our models with the movement type stated can be found in the overview of all cuckoo clocks. If you are unsure which weight belongs to your clock, send us a photo at info@schneider-clocks.com.