Here’s a unique 3D printed project: a motorised, Bluetooth-activated mechanism that can lock and unlock your door’s latch bolt.

This project is deceptively simple: a geared mechanism uses a motor to open or close a latchbolt (technically it’s a sliding bolt). The mechanism and housing for the project is 3D printed and uses Bluetooth to communicate with a phone, allowing activation from a distance.

Internally it uses an Attiny85 microcontroller with an HC-06 Bluetooth module. It all runs off of mains power, but there is also a nine-volt battery as a backup.

In an image gallery of the project, its creator states that the entire build only cost $6 (R86), excluding the battery.


This is actually the builder’s second version of the project. The first version, including the lock, was entirely 3D printed. Commenters rightly pointed out that this was a terrible idea as any significant force would cause it to break.

In response the builder created this version that, while less elegant, is much stronger.

While this second version could have easily been made with some thin strips of metal (as we would have), there’s no denying how impressive this is. We also really love the first version, regardless of its security risks. It just looks so cool.

Luckily, the first version is on Thingiverse if you want it.

Come to think of it, this could be a really good test for new filaments and printing methods. Can your print stand up to a door kick from a police officer? If it can, you move up to SWAT officers and then a sledgehammer.

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