I did build technical props for some productions:

rGasse Curtain with changing motives.
A motorised theatre wing (2,5m x 6m) with 4 different images.
They have been used to extend the video image into the wings at "Phantom of the Opera" and "Dance Fever".
The wings were controlled by the lighting console to fit the video content.

The TapDrums are made of steel and acrylic glass.
They are connected to the controller via 3pin XLR cable and switch between 2 colors set by the lighting console for each drum.
If a drum is triggered, they toggle the color and a MIDI "NoteON" event is created.
The trigger hold time and the wait time between two triggers as well as the note numbers and the color can be controlled during the show from the lighting console.
(Video: it works better with shoes on!)

rFenster I did build a movable, light and fully functional door and a window for a "Schwaben Offensive" show.
They can be easily broken apart and stored in a trunk.