Cuckoo clocks are carved wooden clocks that feature a mechanical cuckoo. A set of weights supplies power to the clock's inner workings. As the weights descend, they turn the gears that move the clock's hands. The weights are attached to the clock by means of long chains that fit over wheels located inside the clock. Sometimes a chain slips off or breaks, preventing the clock from functioning. The cuckoo clock can be fixed by installing a chain.
Gently pull on one of the weights of the cuckoo clock. The chain should move slowly and steadily and should make a clicking sound as it is being pulled. If the chain is difficult to pull, or does not move at all, and does not make a clicking sound, then the chain is not attached properly. If a part of the chain simply pulls free, then it is broken. Complete chains should be about 6 feet long.
Try each of the other weights. If the cuckoo clock needs new chains, they can be purchased from cuckoo clock parts suppliers, such as the Frankenmuth Clock Company and Black Forest Imports (see Resources).
Check the movement of the cuckoo clock. Cuckoo clocks are available in two movements. It has 1 day movement if the clock is wound only once a day and requires a chain with 48 links. A clock that is wound once every 8 days will require a standard chain consisting of approximately 60 links. Both styles of chain are the same length.
Open the back of the cuckoo clock and remove any broken length of chain. Thread a complete chain through one of the holes at the bottom of the clock. Let the other end of the chain fall down through the next hole in the bottom of the clock.
Place the links of the chain over the sprocket wheel that is above the hole. The sprocket wheel is a toothed wheel that powers the gears of the cuckoo clock. Turn the clock upside down and pull on both ends of the chain until the chain is secure on the sprocket wheel.
Attach the cuckoo clock weights to the small round loop at the bottom of each chain.
Make sure the chains are not rubbing against the side of the clock. When the chains cannot move freely, the cuckoo clock will not work properly.