Below you can watch a movie (visit our YouTube channel!) with a cuckoo music box functioning properly. Sometimes minor adjustments need to be made to the two arms connecting the clock mechanism to the music mechanism. As you watch the video, pay attention to the two black arms that reach in from the left side. One on top and one in the middle (touching the spinning fan-fly or governor).
In the first part of the video you see one cuckoo call and music right away. The second part shows how the music mechanism is first started by the cuckoo mechanism, held while the cuckoo calls, and then released to allow it to play.
The thicker, black metal arm on top unlatches the music drum and the music mechanism so that the drum starts to turn. It is abruptly stopped however by the second, thinner wire that touches the brass fan-fly. This stopping wire remains in place until the cuckoo bird has finished its call.
If this second wire didn't stop the fan-fly from spinning, the music would play while the cuckoo bird calls and cause cacophony.
Once the bird has finished the call the wire gets out of the way, allowing the fan-fly to spin and the music to play.
As the tune reaches its end, the black metal finger on top should be far enough away from the music box arm below it to allow the latch to fall in the hole and stop the music.
Watch the video again:
This video is provided as an example of how this SHOULD work. If you make adjustments to your cuckoo clock music make sure that they are INCREMENTAL adjustments. The tiniest change in the placement of these two arms will be all the adjustment you should make. Any adjustments to either the clock or the music mechanism should be done by a trained professional. The gears, teeth, and wheels inside either mechanism are very delicate and precise. Please don't try to make repairs to either mechanism, but you may try to make tiny adjustments to the two wires that connect the two mechanisms as described above.
NOTE: The movie here shows a music mechanism in an 8-day cuckoo clock. This is important because most 8-day clocks don't allow the music to play on the half-hour.
NOTE: The clock featured in this movie is the 2005 award winner of the VDS Clock of the Year. This clock was produced as a limited edition of only 111 pieces for the 111th anniversary of Rombach und Haas.
A few pieces are still available: