Expanding Mechanism Lock Box by Angus Deveson

Expanding Mechanism Lock Box

3D Printing and Assembly Instructions

In addition to the printed parts you will also need OD 6mm x 3mm deep magnets 2pcs and one M3 screw roughly 12mm long. You can find suitable magnets here.



Ensure your 3D Printer is properly levelled and the first layer is correct.

0.15mm Layer heights, 3 perimeters, support material off.

Print TEST PRINT Dovetail Clearances.stl before printing the Main Body to ensure clearances between the main body and locking bolts can be achieved on your 3D Printer.

PLA recommended, model is untested in other filaments.

For some reason, silk filaments such as Polyalchemy Elixir PLA tend to display higher friction to regular PLA and are not recommended for the Bolt Slide Carrier or Locking Bolts.


Print 6 copies of Locking Bolt and 1 copy each of all other files, choosing the Lock or NO LOCK version of the Spiral Gear and Main Body (if you don't want to bother with the magnetic latch).

The Spiral Gear can be printed at any layer height, but 0.15mm is recommended for all other parts.

The only part requiring support is the Magnet Lever. This is a delicate part and difficult to print - supports on "build plate only" and recommend a brim or raft. Some sanding may be required to ensure smooth operation when placed into the Mag Lock Body. 

Depending on your printer the magnets may press into place, or require a small amount of CA glue. Ensure that they are "attracting" for the lock to operate correctly.

What's included?

File Icon 12 files


Expanding Lock Box.zip
468 KB
Mag Lock body.stl
92.4 KB
340 KB
Locking Bolt.stl
20.6 KB
Locking Top Cover.stl
120 KB
Bolt Slide Carrier.stl
58.4 KB
Main Body Lock Version.stl
192 KB
Locking Spiral Gear.stl
266 KB
Magnet Lever.stl
81.2 KB
Main Body NO MAGNET LOCK.stl
188 KB
Spiral Gear NO MAGNET LOCK.stl
249 KB
TEST PRINT Dovetail Clearance.stl
3.99 KB