Saturday, 28 April 2012
Leadbelly, easy impressioning
In my previous post I forgot to mention that creating the marks on the key requires a fairly good amount of force on the key, it needs to be cranked over fairly hard and wiggled quite vigorously. I held mine in vice grips but others use special holders that are somewhat more ergonomic. Key breakage is not uncommon! I struggled so much to get marks on the previous key because of the locks keyway I wondered about making life easier.
What I did was take a blank and file down each pin position to the maximum possible depth plus a little bit more for good lock. I built up the edge with lead/tin solder before finally filing and scraping it to look like a blank again. Files and solder don't really mix so I used a box cutter blade mostly with a scraping action (see cabinet scraping). Above is the finished key with heatshrink protector (so I can carry it around to show off).
Below you can see the line of the join between key and solder. The key must be up to soldering temp when you do this or you do not get good adhesion. Adding the solder was easy, but shaping it a massive pain.
The impressioning process was very easy, the wiggling could be done quite gently by hand (no clamp) and the marks could be seen from space. The lead is not ideal when it comes to filing, really I need a little modified nail clipper of something to make the cuts.