Network Connected Lock by GuyChernobrov

Last crawled date: 3 years ago

This is a mechanism designed to lock and unlock a door by mechanically turning the lock cylinder using a servo motor controlled by an Arduino. By using a wireless Arduino shield the door can be locked and unlocked remotely from a mobile phone app. In this prototype I’ve used the SmartThings Arduino shield for the network connectivity (it connects to a SmartThings hub using a Zigbee network). The mechanics is based on the Worm Gear Reducer, published by Mattheus (https://www.thingiverse.com/thing:41161).
This is a first prototype. It uses a simple (and cheap) HS-311 servo motor, converted into a continuous rotation servo. The mechanics is simple and reliable and it provides enough torque to turn the lock, by using the reducer. The mechanism is rather slow (a full turn of the key takes more than a minute). This design trades torque for speed. This way it is able to turn the lock using a small and relatively weak servo motor which doesn’t require much current and it can be driven directly by the Arduino. The prototype is powered by a portable USB charger.
The model was designed using Sketchup. Here is a link to the Sketchup files on 3D Warehouse, so the design can be modified (e.g. to fit other types of locks). https://3dwarehouse.sketchup.com/model.html?id=u49c8e7b9-ba90-4d48-9280-3fb5b7a23cf7