I should at this point stress the dangerous nature of this project. Though very simple in principle, we are still dealing with very high voltage here. Kids, don't try this at home!
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Step 1: Gathering Materials
In my case this involved spending some time up to my knees in San Francisco's garbage. Others might consider second hand stores or garage sales.
Step 2: What You Need
The essential ingredient that I alluded to is the power transformer from a neon sign. I was fortunate to also find a collection of old volt meters, switches and lights that will be (unnecessarily) included in the design.
Step 3: Composition
In addition to the transformer, you will need something clear to cover the electrodes to keep things safe. I am told that it is best to use something that is open on both ends. I found an old cover for a candle stick called a "hurricane". After some digging around, a vintage vacuum cleaner presented itself as a good fit with the hurricane, and a night stand was selected as a base.
Step 4: Assembly
I find whenever making anything that has to stand on its own, that it is best to work from the ground up. So, resisting the urge to start making sparks fly right away, I began by constructing the base.
The center drawer support rail was removed from the night stand to make room for the guts, and the old varnish was stripped away using Jasco paint and epoxy remover (nasty stuff, gloves and goggles mandatory).
Step 5: Drilling Holes / Wood Treatment
The top of the night stand is drilled to allow for bolts to attach the vacuum cleaner, and the sides are drilled for ventilation (and as an excuse to use some cool aluminum mesh that I found). Once all the wood work was done, I used some wood stain and then Polyurethane to seal the surface, and make it look nicer.
Step 6: Metal Work.
This step was not necessary for the project to be successful, but it is an integral part of my art process. I felt that the vacuum cleaner parts, still looked too much like vacuum cleaner parts. This was due largely to the presence of all the holes where bolts and rivets used to be. In addition, the surface was pretty nasty from oxidation and neglect. I use 3M abrasive wheels in a pedestal mounted buffing machine to quickly bring old aluminum back to life. This makes everything look much better, and is also necessary for good welds. A tig welding machine was then used to fill in any holes that were not part of the final design.
Step 7: Wiring
So, the only thing that makes a Jacob's Ladder function is exposing the two leads from the transformer to each other across a small gap (about one inch). This is also where all the potential danger lies. These are very high voltage wires, about 10,000 volts in this case. Do not allow them to touch each other, or any part of you!
These wires are attached to the ends of your electrodes. Any long skinny metal thing will do, I used salad tongs. The electrodes are attached to a non conductive base (plywood with a thick rubber mat on top). The trick is to place them just far enough apart that a strong arc forms between them, and that they taper away from each other at a rate sufficient to allow the arc to climb up until the gap is too great and it breaks.
The neon transformer was fastened inside the night stand and the leads were run up inside the vacuum cleaner base to make this arrangement work. I then used a foot pedal (sorry no photo) to act as the main switch. It is important that you place the switch in the input power line, and not the output one!
I wanted to use some of those cool old meters and switches as well so I decided to make an instrument panel from an aluminum baking tray. A small wall transformer was used to make one of the meters work, as well as a green indicator light.
I find that it is always best to build your electrical circuits with test leads first before committing to more permanent connections.
Step 8: Finished!
Finally, three lengths of all-thread are used to sandwich the glass hurricane between the two vacuum cleaner halves. I fashioned some crude gaskets out of a rubber floor mat to minimize stress on the glass.
Overall I was very happy with the outcome of this project. The effect of a Jacob's Ladder may be simple, but it still never fails to capture the imagination. I felt that by enhancing the presentation of this effect, an already good thing was made a even better.
If you would like to see more of my sculptures, please visit www.nemogould.com