New Term!

After a short break, things are ready to begin anew!

Some Insight

With the help of Ted Kruger of RPI fame who was in town for a lecture, we seem to have discovered the gremlin's lair.

The whiskers were running on a 9V circuit separate from the motor drives, and as such I didn't consider them a source of overload. However, when the devices get really worked up, after say 5 minutes of interaction and movement, there is a chance that two of the 9V whiskers could come in contact with one ground - creating an 18V potential that would cook a 555 timer...

And here it is! please ignore the small fires.

It was up, wired, and functioning perfectly for about 5 minutes. At that point in time it decided to combust. [ Keep in mind this is mere hours before presentations ]

Autopsy reveals that one of the 555 timers cooked, which is frankly baffling as they are rated to 15V, and the circuit had 12V sources.

Needless to to say, I am less than pleased.

Production

Out of a combination of time and budget concerns, I decided to build three sensors units, and have the rest linked as slaves. I then moved to circuit production and building a scaffold from which to hang it:


The final circuit layout had some interesting gremlins of its own. I had rigorously tested the function of the circuit on an individual basis, however, when grouped together they began to interact in a very strange manner. Instead of each circuit functioning as it should, they began to alter their timing / fail to function when the other circuits were activated. Essentially if one was triggered while the other two were 'open' the one of them would kick off. This resulted in a much faster turnover in the sensor function. I suspect that this effect was caused by a cannibalism of current from the limited wall source.

Overall I was actually pleased with this development, as it seemed that the sensors were actually having a conversation - this paired with the clicking of the relays and the LEDs contained within the circuits made for quite a spectacle.

Mods

With the circuitry resolved ..ish, i then concentrated on production. I cut out the rings on the laser cutter, with an additional step of countersinking the holes to permit a greater / less restricted range of motion for the mechanisms.

In addition to this, soldering the whiskers into pairings was a difficult and time consuming process, so I went about looking for a new method of attachment.


The decided method was both simple, easy, and effective. By using a lead fishing line weight and crimping it around the wire and the whisker, I could quickly affix the two together.

I then went into production:

Gremlins

These circuits have proven far more finicky than I have previously imagined possible. The key issue was the fact that the timer is a relationship between capacitance and resistance - generally a simple issue of getting the right parts and tweaking until things preformed the way you desired. At least, thats how it is supposed to work.

The reality of the situation is quite different, and the electricity gods actually do have it out for me. Although, by making offerings to the other electricity gods [Carl] we worked through most of the issues. The most basic issue was the fact that we were using batteries which are an inconsistent power source. That delicate balance of capacitance and resistance that was so critical to the circuit was constantly derailed as power outputs gradually degraded within the batteries - switching to a constant power source solved this. We overlooked the significance of this effect and as a result spent an inordinate amount of time fiddling. That, and the original circuit diagram was WRONG.

If anything I have added some colourful new words to my vocabulary.


After two weeks of fiddling and rebuilding and tweaking, Chelsea and I created functioning circuits. they were essentially the same, with the exception of our resistance settings - I required a 2M potentiometer as I was dealing with shorter timing intervals.

A Note Concerning Electricity

There are reasons why I am not an electrician. I have already spoken of my soldering abilities, tho they have certainly improved since montreal, but the most prominent fact is that I don't quite grasp electricity - its some sort of voodoo involving dancing electrons and the ritual sacrifice of AA batteries. In fact, my understanding of electricity previous to this venture can be summed up in two statements:

1. Avoid licking the two contacts of a 9V battery
2. Avoid Lucas components like the plague.

Its all very simple when the key word here is avoidance. Ah, but this is Hacked studio.

Electronic Afflictions

Not knowing what I was getting into, I tried various methods of wiring the sensors in a simple manner - dropping the voltage, different motors, etc. I got to the point where I could get the sensors to function, but in doing so arose another issue - when they opened - which was spotty at best due to the strange power issues, they tended to stay open and thus burn out the motors.

To solve this I required a circuit that would accomplish two things:
1. Allow the whiskers and motors to work on two separate circuits, resolving any power issues.
2. When the whiskers were triggered, turn the motor for a controlled period of time, and then turn it off again.

Luckily, Chelsea Grant was also looking for a timer circuit, so we tackled the problem together. The original circuit we were basing our efforts around was this, a 555 timer circuit:


In keeping with the spirit of this studio, the frigging thing didn't work.

Thus began our epic battle against the timer circuit.

Prototyping

After that revelation - which proved to be an elegantly simple resolution to the "opening" compared to all that worm gear fuss, I started to construct a prototype:

The device consists of two circles of mdf mounted to a motor, with corresponding holes drilled in each. The back was fixed to the motor, with appropriate access to the electrical connections, while the front was press-fit to the small gear affixed to the motor axle. All pieces were cut on a scroll saw with surprisingly tight tolerances around the gear.

From this point I experimented with different wires to use for the contacts; copper strands [too delicate], floral arrangement wire [too soft / ductile] and finally settled on steel piano wire. These wires were soldered together to create bundles or pairings of contacts/ whiskers for the switch~sensor.

I experimented with different wiring combinations for the contact pairings and the motor. The first was a straight wiring of the motor into the whiskers [all at 12V] attempt effectively proved the motion of the concept, however - the power running through the whiskers had an interesting byproduct: Any time they were in contact and closing the switch, they would arc - I thought the effect was very cool in a sort of mad scientist way, but the heat generated from this arc tended to weld the whiskers together. Further experimentation was needed.

Roundabout

Looking to combine this with my earlier models, I realized I could achieve the same isolating effect while linking it to a rotation. The erection motion within the linear model is caused by moving a series of points along the wires parallel to the fixed points below - this could be achieved by rotating those same points around a set of fixed ones. The radial positioning would cause the wires to "flare" out to achieve the same isolation effect.

Skin Condidtions

For the redesign, I had to find a way of controlling the sensitivity of the connection - to do this had to vary the gap between the connections - a greater distance meant a less active sensor. To accomplish this I recalled some of my research regarding sensory effects on skin - particularly thermal response.

The effect in question is called piloerection, with the more common term of "goosebumps". When the body feels cold, it triggers the hair follicles within the skin to shift and pull the hairs into an upright condition, creating a boundary layer of warmer air at the skin surface. This also works to isolate those hairs from each other - the effect that i was looking to take advantage of...

I began to explore possible constructed developments using stepper motors through drawings...