Milner safe lock 3D printed replica
A milner safe is very easy to identify just by looking at the key hole. The distinctive 2 keyhole slots will give away the type of lock used in the safe every time. Milner were very popular safes for very good reason. They offered a high level of pick resistance and resistance from brute force attacks.
Usually the ingenuity of these old safe locks is only seen by locksmiths who service these safes and cut keys for them. Being able to replicate the lock easily on a 3D printer gives people a chance to see just how these locks work and allows them to build their own high security safe lock.
This Milner replica safe lock has a few changes from the original. The biggest noticeable difference is that the lock does not have a curtain. The curtain is an internal piece of the safe lock that serves 2 main purposes. It acts as the bolt throw and it shields the levers and inner working of the lock to make lock picking much harder. The curtain could not be 3d printed strong enough to make it work in this model. Instead the bolt throw uses the end cut of the key.
The key is made much larger simply to add strength. A thin plastic key just isnt strong enough to work.
Interestingly, the original Milner keys were made from cast brass. A cast brass key is very strong! Modern steel keys have the flag welded onto the post. The weld in modern keys is a weak point and often causes keys to break inside a safe. If you can find a locksmith who has cast brass keys, they are a much better alternative for these safes.
The body of the lock is made in three sections. The bolt is inserted from the bottom of the lock and the levers are inserted from the top. A top and bottom plate hold the lock together.
As a locksmith in Brisbane I still see a lot of these old Milner safes still in operation. While they might not have the same resistance to modern attacks as more modern high security safes, picking the lock on a Milner safe is still a very hard endeavour which takes a lot of skill. Most Brisbane locksmiths would not even consider picking a Milner safe lock.