This is perhaps not the most politically correct science fair project, but it definitely gets attention. And although it is more based on presentation than science, most people find it very interesting to learn how an electric chair works. :D
This instructable is quite lengthy, though some parts are optional. You'll probably want to scan each section to find what you're looking for. Have fun and happy building!
Also, please note that I will be linking to Amazon.com for the materials used within this project.
Step 1: First you'll need to find a Barbie with bendable arms and legs.
Don't pay too much, though, as we'll be messing her up quite a bit.
If you'd like, take a mugshot. You can use it in the presentation of the science project. I cut my Barbie's hair and drew circles around her eyes with a pencil, and well as smudging lip gloss around her face. Barbie had a rough night.
I also made an outfit for my Barbie using scrap fabric I had lying around. This is a very simple thing to do that will help your project become more attractive. I've included a quite awful Microsoft paint image to explain it!
Step 2: Start collecting the basic tools for this project!
- a piece of wood, preferably less than 1/2 in. thick. You need the chair to be in proportion to Barbie!
- a saw of some sort suitable for cutting wood. Buy mine on amazon.com!
- a drill for inserting wires into the epoxy putty.
- notepad and pencil for taking measurements.
- tape measure.
- safety glasses that fit better than mine.
- wood glue.
- a level for better measuring.
- stain of some sort (preferably dark, like this walnut stain.) or instant espresso mixed with water to form a paste. (I started out using stain, but didn't have enough and moved to espresso paste, haha.)
- a small brush for applying stain.
- FastSteel epoxy putty or something comparable.
- 18 gauge electrical wire.
- any small lightbulb - flashlight bulbs will work best. The base needs to be pretty small!
- find something you have around the house to use for straps. I fashioned some out of an old CD binder handle. I just had to burn the ends together and taa-daa!
- a 6 volt battery, like this one.
- plastic wrap or plastic grocery bags for cleanliness!
Step 3: Measure your Barbie and assemble the chair.
Basic chair measurements:
Seat of chair = 1 piece at 3 in. long x 3 1/2 in. wide
Back of chair = 1 piece at 6 in. tall x 3 1/2 in. wide
Armrests = 2 pieces at 3 in. long x 1/2 in. wide
Vertical armrest bases = 2 pieces at 1 1/4 in. tall by 1/2 in. wide
Foot rest = 1 piece at 3 1/2 in. long x 1/2 in. wide
Legs = 4 pieces at 3 1/2 in. tall, 1/2 in. wide
Go ahead and cut these out - I assembled the entire chair using only glue. Just take it in stages and you'll be fine! I've included two pictures of the assembled chair for reference. (Also, try not to worry too much about which way you're cutting. If you cut against the grain like I did, it'll just make the chair look more rugged and scary.) :)
Also don't worry about how straight and professional it looks. People will be impressed that you made a chair at all!
The only tip I can give here it to watch out for excess glue - you can end up with weird spots in the stain.
Step 4: Staining, yay!
Just be sure to cover your workstation and wear gloves!
And if anyone asks you why the stain looks so terrible, politely explain to them that it's not "terrible", but rather "old" and "badass".
Step 5: Now, strap your Barbie into the chair.
If you have extra bits of leather, cloth, or nylon cord lying around that will work pretty well! You just need to decide how many straps you would like.
Straps are normally in these places:
- across the chest
- around the wrists
- around the ankles
- sometimes a leather "helmet" is worn to reduce movement and the view of the victim's face, as well.
Step 6: A mini history + science lesson! Yippee!
I will link to sources at the end of this section, however, that I have deemed the most reliable.
History of the Electric Chair
The first electric chair was built by Harold P. Brown, and it came at quite a crucial time - during the War of Currents.
The electric chair was first put to use in New York in 1890. The execution didn't go quite as planned - the subject, a Mr. William Kemmler, withstood two rounds of voltage before he expired. And yet, even with the gruesome display, it was still considered more humane than hanging and therefore spread across the country (used in more than 25 states) and was soon the primary means of execution within the U.S.
Now the electric chair has been phased out for the most part. As of writing this instructable, Nebraska is the only state left that uses the electric chair as its primary means of execution. Other states still offer the chair, but prefer to use lethal injection. This is most likely the result of many botched executions. There have been several cases in which an electric chair has severely burned and bloodied the condemned. Men have withstood the one round of voltage and suffered until they died during the second. The numerous horror stories far overshadow the properly carried out executions!
How an Electric Chair Works
An electric chair is composed of very few parts - a wooden frame, leather straps, and two electrodes (usually made of brass) that form a closed circuit, therefore keeping the electricity within the body. One electrode fits inside a helmet, and another goes around the leg. To help these electrodes to their job, the subject's head and leg will be shaved, and sponges will be used to increase conductivity. The electrodes run on alternating current (AC for short).
In most cases, a hood and a diaper will also be provided.
Voltage has varied from year to year and from state to state and is hard to summarize. In most cases there will be one to three cycles of electricity pumped into a subject, and these will vary in voltage and time administered. This will result in the subject being electrocuted, which will result in a loss of consciousness and eventually lead to death due to damage to internal organs.
Sources in addition to chose linked to above:
Step 7: Now that we know how an electric chair works, let's set up the electrodes!
In the next step we'll drill small holes in the putty to allow for wire connection.
Tips for working with epoxy putty:
- keep fingers moist, otherwise you'll end up a sticky mess.
- work will small amounts.
- fashion small pieces and build on them to avoid a piece drying in the middle of you molding it!
- check the dry times on your specific product and work fast!
- be careful when pulling the putty and the plastic wrap apart - make sure the epoxy is completely dry!
For the back of the chair, pictured in pictures 1 & 2:
- lay a sheet of plastic wrap over the back of the chair. This will keep the putty from sticking.
- form a flat piece that covers the top and sides.
- from the flat piece you will build a pipe-like piece big enough to fit your lightbulb inside - try to do it as shown in the picture, it makes it easier!
- also keep in mind that you need to make it thick enough that drilling won't break it.
For the helmet, shown in picture 3:
- cover Barbie's head with plastic wrap.
- place a glob of putty at the top of her head and work it down until the helmet is the size that you want.
- make sure to keep it thick enough to drill through!
For the electrode on the leg, shown in picture 4:
- roll a small piece of putty into a snake, and make sure that it goes completely around her leg.
- place on the leg and flatten.
- try to keep the edges as straight as possible and watch out for bumps!
- you don't have to worry about thickness as much on this one because we can drill right into her leg!
Step 8: Drill holes into the epoxy putty for the wires!
For the back of the chair and the helmet, drill holes as described in pictures 1 & 2.
For the leg electrode, drill holes as described in picture 3.
You will need a minimum of four holes on the back of the chair, four holes in the helmet (two on top and two on one side), and two holes side by side on the leg electrode.
Step 9: Cut the wires and install them.
Wiring the back of the chair as shown in pictures 1 &2:
- insert a wire into the top hole. This will wrap around the light bulb.
- curve it so that it fits the hole and around the light bulb.
- insert a second wire in the lower hole, this will make contact with the bottom of the light bulb.
- insert light bulb when both wires are in place.
- these wires will connect to the battery, so make sure they're long enough!
Wire the helmet to the back of the chair as shown in picture 3:
- these wires are just for show, and are only a couple of inches long.
Wire the side of the helmet to the leg electrode as shown in picture 4:
- yet again, these wires are just for show.
- make sure they're long enough to arc out away from the chair and Barbie's body.
Picture 5 shows the length of the "just for show" wires, for reference.
Step 10: Connect Barbie to the battery and burn, baby, burn!
I suppose you could always let people connect the light bulb wires to the battery and scream when the light bulb turns on. That would be a show of sorts. And you might succeed in creeping them out even more. The possibilites are endless - you could use it as a night light, a finger warmer, a reading light, or just to make your house guests worry about your mental health!
So go ahead and turn on your light bulb and bask in the glow of your very disturbing science fair project. :D