Incidental electromechanical reflex

Incidental electromechanical reflex (IER) is a mechanism respectively hack that I have investigated and domesticated for my installation Putting The Pieces Back Together Again in 2018. IER originated from the search of an electromechanical actor that is able to react to a stimulus or an obstacle directly and without the use of a sensor or a complex computational process in the background, almost like the muscle reflex. A reflex creates an involuntary and nearly instantaneous movement in response to a stimulus. I wanted to use this mechanism for my artistic research on emergent behaviour, entangled processes and non-hierarchical communication systems.

From previous experiments with stepper motors I remembered that in some cases they start to behave not as expected, their behaviour becomes jerky and unpredictable but also that they might change their direction of turing inregulary. I knew it has to do do something with the driver signals and the use of the different coils/phases of a stepper motors itself.

I also remember a small installation I have seen from the canadian artist Doug Back who must have used a similar principle: rotating elements that would bounce back (reverse their turing direction) if they hit each other. I did not find anything about this “phenomenon” on the internet, just in some forums where people had problems with asynchronous motor (inductions motors), the forums delivered only ways to fix the behaviour that I tried to create.

The simplest way to create this behavior is to use an audio amplifier and drive one one phase/coil of the stepper with an symmetric sine wave signal with a amplitude between -9 to 9 volt . The given frequency will define the speed of the motor:

1

bi- or uni polar stepper motor

e.g. 28BYJ-48, 5 volt version

only one coil (two cables) will be used

use a multimeter to find out a usable coid

2

3d parts (levers)

print out attached 3d files.

the openscad files can be modified in dimension and quantity

3

audio amplifier

with line in and speaker out

e.g. from Hi-Fi equipment or IRS2092

4

signal generator

e.g. pc/mac running pure data to generate sine wave signal