You can spot the zig-zag letters from their zig-zag lines. Let's look at the ‘V’ here. That down up movement makes the zig-zag. ‘W’ is the same, only with more diagonals. Down, up ...

[Denha] just uploaded his latest creation, using a spring as elevator and a simple zig-zag path. The construction is relatively simple, a spring with the appropriate pitch for the steel balls size ...