TCO (Optical switchboard)

Here's my TCO (optical switchboard) made on a sheet of aluminium on which I've glued the track diagram for the two slides, printed on A4 photo paper. The whole thing is covered with a sheet of Plexiglas.
Drilling the holes for the indicators requires a lot of care.
I did it with a drill press, clamping the aluminium sheet and the Plexiglas as close as possible to the places to be drilled between two cleats (otherwise there was a risk of tearing the photo paper).
You need to choose a slow drilling speed and advance slowly because the Plexiglas melts easily with the heat released by the drill bit.

Here's a behind-the-scenes look at all the connections.

On the left-hand side of the TCO, the LEDs corresponding to the 6 blocks, controlled by Lenz BM3 modules.