Cuckoo alarm module for HP Otto

Summary

In this project, we’ve designed a functional cuckoo alarm for use atop any Otto design. There are two variants included: one for use with a single servo, that can be programmed as an alarm clock, and a mechanical one, to test the mechanism without electronics/wiring.

List of parts

• House-shaped housing (with or without hole for the wind-up crank)

• Eustaquio, the cutest cuckoo

• Two doors, with hinges and a push open mechanism

• Door openers (print two)

• A wind-up crank

• A stick to drive the motion

• Assorted gears (gear1, gear2, gear_for_servo)

• A rack

• A holding plate for the mechanism

Print and assembly guide

Many pieces must be printed using supports, including the house, Eustaquio, the doors and the crank. Make sure your retraction settings are good, as the roof of the house is hollow and it may result in many retractions.

I have used 0.2mm layers and 20% infill for every part of the build, except for Eustaquio, for aesthetic purposes only.

As for assembly, there is an example build included in the files, but it is very straightforward: the house is Otto’s hat, using the joints from hp_toplights_r2.stl; and the holder has the rack and mechanism on top of it. To join the door openers and the door hinges to the doors, I’ve used small pieces of 1.75mm filament to good effect.

The servo version uses the house without a hole for the crank, and the sole gear that sits on the rack. The hand-cranked version uses the rest of the models, and it has not been tested for functionality. Gear function depends a lot on the 3D printer used, and switching them up may be necessary.