This project requires some attention to detail and tinkering. It is important that you watch the video to see how the project is constructed. The padlock is constructed from 3/8" Baltic Birch plywood. You also need some 1/2" dowel and 1/4" dowel.
You need to be precise when you drill the holes and cut the parts. There is not a lot of room for error if you want it to work. When you drill the holes in the front and back plates, steck them and drill through both part so they line up perfectly. You might have to sand some parts to fit if your cuts are off. Just think through the project before you start and test everything before you commit to glue.
I had a lot of fun making this project. It's make a neat conversation piece even it does not have a great deal of usefulness.
The picture below shows the lock with the front removed so you can see the details of the mechanics. The finished pattern is a little different from this prototype because I needed to make some changes as I found the errors.