Transform the #42179 orrery into an alarm clock!
The clock features an accurate hand speed ratio and the possibility of setting an alarm (once the hour hand reaches the accurate position, the bell is activated).
The model can be optionally motorized with the PoweredUp system (one extra servo-motor and hub are needed, not included in the original #42179 set).
Presentation on TechLUG.fr (in French): https://www.techlug.fr/Forum/viewtopic.php?f=5&t=13065
Building instructions available at Rebrickable: https://rebrickable.com/mocs/MOC-186869/alter-lego/42179-alternate-alarm-clock/