Introduction: Build an Arc Reactor With Basic Tools and Skills

I thought it would be cool to go as Tony Stark for Halloween, and I turned to Instructables for ideas on how to build an Arc Reactor. The problem is that the best and most accurate Arc Reactors on the site like Honus' and Kyling Zhang's, or ones featured elsewhere like Indy Mogul require precision machining tools and the skills to use them.

I felt that a decently accurate Arc Reactor should be easy to make by the average person, and should be constructed at least mostly using materials that are easy to obtain. Needless to say, I think the results are pretty good, especially for a first attempt, and you will be able to use my build to create even better results of your own.

Step 1: Set Up the Game Plan

Take a minute and consider what makes an Arc Reactor recognizable.

1) Lights: Every iteration of the Arc Reactor lights up; a ring of palladium undergoes some kind of 'arc reaction' (read: copyright of Stark Industries), glows, and is visible through the device.

2) Coils. The original purpose of the Arc Reactor is to power electromagnetic coils that prevent shrapnel from entering Tony Stark's heart. The first Ironman movie's Arc Reactor had 10 coils (and 10 spaces in between where light was visible).

3) Inner Ring/Bracket: It appears as though there is an inner ring assembly of some kind that holds the reactor together. It has 3 structures coming from the center separated by 120° and a series of internal rings that appear to provide structure for the apparatus.

At the very least, someone building an Arc Reactor would want to show off lights through a t-shirt, and at the most they want to show off the entire reactor. This means at minimum, we need to construct an even ring of light that appears to be covered by coils (or anything) with a glowing light in the center as well.

NOTE! In this build, I used a hot glue gun, soldering iron, and other assorted tools which are easy to come by, but DANGEROUS. I always solder on a wooden surface, hot glue over newspaper, cut in a direction away from my body, and other various safety things that may or may not be common sense. BE CAREFUL.

Step 2: Begin Construction of the Outer Ring

Since the Number 1 most recognizable part of the Arc Reactor is that it lights up, that's where we'll start. So how do we go about this? The Arc Reactor was BUILT IN A CAVE WITH A BUNCH OF SCRAPS and we don't have access to said cave.

I had two ideas on how to light the Arc Reactor up: Fiber Optics, or LEDs. I don't know anything about Fiber Optics, so that narrowed the choices pretty quickly. But LEDs are point sources of light! You can't make them look like one solid ring of light... Can you?

Yes! The trick is to diffuse the light from the LEDs enough that it appears like one glowing object instead of many smaller glowing bits and pieces. After a bit of research, I read that common hot glue diffuses light, and decided to run with that theory. I visited the local crafts store and purchased a 20 pack of glue sticks (something like $3). While I was there, I also purchased a $1 circular box. This box had a 4.5" diameter, which is a bit bigger than the movie Arc Reactor (I believe that one is 4") but would do the job.

I tested this theory using cheap red LEDs that I have a lot of. I forgot to take a picture of the LEDs lit up, but you can see here how I built the test structure.

There are some rules about electrically lighting up the LEDs I will detail in the next step.

Also, I read online that hot glue doesn't stick to aluminum foil. The Internet lied. It sticks, pretty well too, unless you peel the foil off very carefully. But this will work to our advantage; to build these shapes, I coated the inside of the circular box with aluminum foil, and then carefully glued a layer onto the foil. This layer will act as our base.

Step 3: Add LEDs to the Outer Ring

Red LEDs are cool, but the movie Arc Reactor sometimes appears as white light and sometimes as blue. Blue is more distinct, so I felt making the Arc Reactor glow blue would be a good path to take. To this end, I purchased 25 bright LEDs from DigiKey, part no. 404-1172-ND, manufacturer part no. LB5804B. They are 5mm through hole LEDs. With shipping, it was about $25.

20 LEDs were for the Outer Ring, and 5 were for the Inner Ring which is in later steps. I measured the circumference of the inner part of the Outer Ring, divided it by 20, and thus had the spacing to evenly space each LED. After all the LEDs were glued in place, I added a few more layers of glue to diffuse the light some.

Now, some basic LED math:
LEDs have a positive wire (called the anode, which is longer) and a negative wire (called a cathode, which is shorter). These Blue LEDs are rated for 20mA (milli Amps) of current. Without going into too much detail on why, let's just say I decided that in the end, all of the LED's would be wired in parallel, so all of the positives and all of the negatives connected together.

Either way, if we want to light the LEDs up, we have to use Ohms law, which says Voltage = Resistance x Current. For my tests, I used a power supply that provided 5 volts. As you will see in the pictures, my initial tests were with one LED (you will see two; I actually implemented the 'one LED' setup twice per test). If Voltage = Resistance x Current, then Resistance = Voltage / Current. 5V / .02 A = 250 ohms. So if you want to light one LED, you must connect it to a power source via a 250 ohm resistor.

After performing tests of the 'one LED' setup, I then soldered all of the LED anodes together, and all of the cathodes together. I did this by using a pair of pliers to bend the wire of one LED to the next, solder the connection, and repeat for the whole ring. I then lit the whole thing up.

20 LEDs will use 20 times the current, so instead of 20 mA we need 400 mA. Therefore, V / I = R, 5V / .4 = 12.5 ohms of resistance.

This test looked mostly good, although some of the LEDs didn't diffuse well. This is because my gluing was not completely even, and I fix that in the next step.

NOTE: In some of the pictures you can see my version of gmjhowe's K'Nex laptop stand!

Step 4: Complete the Outer Ring

This step will complete the Outer Ring of the Arc Reactor. Based on your personal preference, you could even skip the latter part of this step.

The light was not diffusing well enough yet (these LEDs are very bright!) and the back of the ring was full of wires (this is supposed to keep the shrapnel OUT of the chest, not add more!) so at this point I had the bright idea of adding a layer of aluminum foil in the center to help act like a mold while I added more glue. After molding, I cut off the excess foil. From here, the Outer Ring takes on its final shape.

Also, if you're soldering job wasn't that great, adding hot glue will ensure that the connection stays secure electrically. At this point I also soldered red and black (positive and negative/common/whatever name you want) wires to the ring.

Next is to make it look like there are electromagnetic coils overlapping the ring. I first cut out lengths of paper that I taped to the ring, and tested lighting the ring to be sure of what it would look like. Once I liked how things were spaced out, I removed each piece of paper and wrapped electrical tape. The tape will completely block the light, and will also act as a guide for the last part of this step. Electrical tape is wider than I liked, so I would lay out a piece, cut it with an exacto knife, and then tape it to the ring.

At this point, you're at a crossroads. If all you want to do is place the Arc Reactor under clothing, you can take the extra LEDs you've got, place them in the center, put on a shirt and you're done. However, I wanted to show off the reactor without covering it up, which meant winding the coils and adding an Inner Ring.

The coils are part of the Outer Ring, so I've included them in this step. It's really quite simple, although tedious; I used 28 gauge copper magnet wire (which would be used in real electromagnetic coils of this size), which I meticulously wound over every piece of tape. The electrical tape can act as your guide, and it has the extra benefit of not letting any light through if your winding work (like mine) is less than perfect.

Numerous times, I did not prepare the right length of wire, so I hot glued the back end of the ring to hold everything together. The back isn't pretty, but the front looks really nice.

If you were really picky, you could have prepared the correct lengths of cable and made real electromagnetic coils with this step. That's for you perfectionists out there ;-)

Step 5: Begin Construction of the Inner Ring

Okay, so if you plan on continuing this project, you will need an Inner Ring assembly. This part looks more complex, but we'll fake it pretty well ;-)

It looks as though the Inner Ring is made up of a metal bracket, which is held in place with three allen bolts. It's hard to see in the pictures on here, but underneath that bracket appears to be more coils that are floating (as opposed to being wrapped around something), a few smaller metal rings, some kind of wire mesh and finally more glowing light.

Start with the metal bracket. I grabbed a plastic lid out of the refrigerator and drew graffiti on it until I was satisfied. Your design can vary. I did not make any schematics or drawings of this, but I can tell you that an equilateral triangle has three 60° angles which is where the allen bolts would go, and that the movie Arc Reactor had 8 holes in between each bolt.

I cut the design out with an exacto knife. Good to go.

I made the coils that would float/hang underneath bracket using aluminum magnet wire. I'm not sure what gauge it was, sorry. To make it look coil-y, I wrapped the wire around a screw, and then unscrewed the screw. Cut to length, bent into place, and it was also good.

Next, I did the innermost ring. Here, I took this wire mesh that I have no idea where it came from, and a metal ring cover from a plumbing kit at the hardware store I had from a previous project. Hot glue and cut to shape put those two together well.

Following this, I added one more ring to be placed in the center of the previously mentioned ones. This was constructed by chugging a can of soda (or pop or soda-pop or fizzy drink or whatever) and cutting the bottom of the can off. I also cut out the inner part of the bottom so it would be a circular O.

Cutting the bottom off like that was a mistake; I later decided I wanted there to be a bit of height available, so I glued aluminum foil to it. You may to just be more careful with your cutting than I. Also, cutting an aluminum can creates sharp edges... I glued the edges to take care of that.

Step 6: Complete the Inner Ring

We're nearing the end!

So even though a number of the Inner Ring parts are metal, they are different kinds of metal. It looks inconsistent. To remedy this, I painted all of the parts that would be in the Inner Ring (except the coils). The paints I used were from Tamiya Color, Gun Metal X-10 and Chrome Silver X-11. I used 7 parts Gun Metal and 5 parts Chrome Silver to get a realistic metal-from-some-cave look.

The bracket ring was fit over the aluminum wire coils, which were cut to fit correctly. I cut strips of aluminum foil, and glued one end to where the coils poked through the bracket ring. I did not use the heads of allen bolts or anything here - so I globbed up some glue and tried to make it look round.

This was fit on top of the soda can. The aluminum foil strips were glued tightly to the inside of the can. After this, I painted the glue and the foil strips to match the painting scheme.

There has to be light in the center of the Inner Ring, so here I took the last 5 LEDs and glued them all together. Rather than add a lot of glue to diffuse the light, I stacked the LEDs as close to each other as I could so it would appear like one bright light source. This was glued to the back of the innermost ring with the wire mesh. They were then soldered together so all the anodes and all of the cathodes were connected, and then so red and black wires would extend from the LED mass.

At this point, all that's left is to glue the innermost ring into the rest of the ring assembly. I didn't do this right away, because I wanted to do some lighting tests seen in the final step.

Step 7: Finish the Arc Reactor!

It's finally time to put it all together! The first pictures in this step are a lighting test of what the final reactor would look like that I took before I completed the Inner Ring in its entirety. Things are starting to look good at this point. However, I did find that the inner light stuck out - a lot. Not to worry, though, we have a fix.

We need to have something to contain the Arc Reactor and hold it to one's chest. I cut the box used at the beginning of this build to be shorter, and poked holes in the sides of it to thread cable through. I'm using a long, extra USB cable that I had lying around. I then painted the outside and some of the inside of the box with the paint from before so that it would have a metallic look.

While the picture shows one cable threaded through all four holes, the final setup was to have one cable run though the top two holes and go around the neck as a necklace. The bottom two holes run around the body, and are tied together in the back. Put a shirt on top of that setup and the cables will be invisible, and the Arc Reactor will be held firmly against you.

The final step is, of course, putting it all together. The Inner Ring was held inside of the Outer Ring using - you guessed it, glue. At this point I needed a portable power source, and went with a standard 9V battery. That means our electrical work has to change slightly. Also, we're using 25 LEDs at this point, and 25 x 20mA = 0.5A
V / I = R, 9V / .5A = 18 ohms.
Half an amp will make a single resistor of 18 ohms get pretty hot, so I wired two larger resistors in parallel to get the same effect and distribute the load. A little bit of soldering connected the Inner Ring and Outer Ring lights together, and I soldered additional red and black cables that were threaded through the bottom of the box (or is it now a case?).

I cut out a circle of aluminum and placed it in the box/case before inserting the Arc Reactor. It reflects some of the light from the Inner Ring LEDs outward to make look like more than just a glowing point source. Doesn't help a lot in the dark, but it does look better otherwise.

Insert the completed Arc Reactor into the metal [looking] casing. At this point, I cut a hole in a t-shirt I didn't care about and put that on top of the reactor. I then wore a button down shirt on top to make sure the cables holding the reactor would not be seen, and ran the cable with the battery down to a place where it was easily accessible.

You now have a pretty darn accurate looking Arc Reactor. There's no need for a drill press, a lathe, or other complicated and expensive tools, you can build one of these yourself fairly easily and achieve good results.

Step 8: Final Thoughts

Having worn this Arc Reactor, I can say it gets very positive reactions from people. Everyone that has seen the Ironman movie is impressed, and no one cares that it wasn't surgically implanted. People were very surprised and interested in the manually wound coils on the Outer Ring and commented on how the Inner Ring assembly looked very accurate. Everyone kept asking how it was mounted to my chest, as there was no visible trace or evidence.

Lastly, there's always things one can do better. Here are a few ideas I came up with after everything was all said and done.

1) Make it thinner: Soldering the LED anodes and cathodes at a shorter length would allow the whole build to be much thinner than it was.

2) Better power supply: I used a regular connector and a 9V battery. The resistors I used got decently hot, and I estimate the battery wouldn't last more than an hour anyway (I actually have yet to try, I disconnected the power fairly often). A better power supply (maybe like those from Adafruit) and a switch of some kind would help.

3) Better way to wear it: The necklace and back-strap deal works, and is hidden, but I can tell you it is uncomfortable at times and makes it difficult to take large deep breaths. There is likely a better solution there.

Hopefully you can take my ideas and make an even better version of the Arc Reactor! Have at it.