Young Derek's Treasure Safe

This is a toy safe that I designed for my nephew Derek. Seeing as young Derek is a bit of an escape artist, I thought that he might enjoy learning how locks work, so this safe comes with a working lock, and lockpicks designed to work with this safe (so that he can apply his new knowledge of lock mechanisms).

Note: there is a second set of pins available for download, with 8mm diameter. These may require some sanding down to get close tolerance in the holes. I added these because the original 7mm diameter pins sometimes skewed and jammed in the tumbler.

Admittedly, there is some room for improvement, but considering it's a prototype, it works really well. My first print was easy to assemble, and the key opened the lock. what more can you ask for?

additional parts required: 3 springs (from clicky ball point pens; some superglue/epoxy glue; two 4mmx50mm bolts & nuts (other solutions possible, see instructions)

I've included the Solidworks files, so that you can view the assemb