Unpickable Lock

This is an "unpickable" lock (I think there is actually a way to pick it, but it's pretty close!). I printed it using HP MJF. No idea if you could do it with FDM. Also you need some additional non-printed parts:

1. 3mm lock springs.
2. 3mm ball bearings.
3. 3mm * 6mm lock pins, with both ends rounded over and the middle narrowed (I did this using a Dremel as a lathe).
4. M3 screws

Additionally there are some flaws that I didn't fix in this model, but people were asking for it so I'm just posting it as-is. Notably:

1. This version has the key a bit too fat to fit in the whole. I actually used a slightly narrower key from an earlier version - just trim a bit off the sides or make the main hole wider.
2. The funny shaped thing on the back is overly complicated and makes the lock feel a bit janky. It would be better just to use two semicircles.
3. There's no point putting pins in the front 4 pin stacks because I forgot to leave enough space for a key that could lift them.