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Special Effect Table for Svein Flygari Johanson. October 2011
Svein Flygari Johansen
Am I making up what really happened? 12 November 2011 – 12 February 2012
Beaconsfields Gallery, Lambeth, London.

The Arch space for the Gallery is in a railway arch under the main railway line to Waterloo and the Arch exhibits inspired by the Film 'Stalker' included the Milk-Table.
Svein's idea was that as trains passed overhead a glass of milk on the table would vibrate and move as the table vibrated with the noise. However the glass had not to fall off the table!
Also he insisted that there be nothing in the glass other than milk so moving the glass using magnets was not possible.
I decided that the noise of the train could be picked up by a microphone, amplified and used to drive a big speaker under the top of the table. The table top would be tilted so the glass would vibrate down the slope then by sensing the glass as it approached an edge the table could be tilted in the opposite direction so the glass would then move away from the edge.

Milk table frame Milk table works
The table was based on a Ikea BJURSTA white Dining table.
The train noise was fed to a 900W sub-woofer, the sensing of the glass and tilting of the table top was controlled by a small microcontroller and tilting was effected by two Tower-Pro 1/4 scale servos.

MilkTable Gallery1 MilkTable-Gallery2 MilkTable-Gallery3

However things were not quite straightforward!
The electrical noise from the trains above affected all the sensitive sensing electronics.
Then the chipboard table top started to warp with the damp.
I managed to make the table work for the opening but by the fourth day the top had warped by 3/8" [10mm] and the damp seriously reduced the effectiveness of the sensors. The warp meant the glass didn't slide properly and sensing was not going to be reliable for the show.
A new table top was made from exterior grade plywood and I modified the controller to accept commands, to tilt, from image recognition software, written by Jonny Bradley, detecting the glass position by an overhead camera.