This is a work in progress!
You can use it both horizontal and vertical.
Last version: https://youtu.be/8PiaMl7-6I0
Technical
4 x M4 screws and nuts.
1 x M3x10 screw, washer and nut.
1 x 20x90mm velcro without glue.
1 x 20x25mm velcro with glue.
1 x Ø2x25mm shaft.
I used a piece of wood for fixing the set to a table.