Arc Reactor Construction Montage Instructional Companion Post

A little over 3 years ago, I acquired a small slab of plexiglass scrap from my school’s machine shop and the first idea that popped into my head was to make a Mk. I Arc Reactor from Iron Man (2008). Yes, that was my first thought. Extremely nerdy, but are you surprised. It wasn’t like I could make much else from it anyways, since I lacked the tools like a CNC to make a pretty paperweight. There’s really not much you can do with a 3 x 5 x 0.5″ piece of plexiglass.

Paperweight I made in Manufacturing Processes (2008).

With nothing but hand tools and a steadfast refusal to spend money however, I had to resort to basic forming methods and a bit of MacGyvering to create everything I needed from raw materials. Based on the time I’ve spent answering questions on YouTube, it’s become obvious to me that my build montage is no substitute for clear, written instruction. So without further ado, I present to you my DIY Mk. I Iron Man Arc Reactor Construction Montage Instructional Companion Post.

0:05 – 0:15
Before you can start hacking apart your parts with power tools, you need a plan. Here I’m making a top-down template showing how I’m going to arrange my arc reactor, where LEDs will go, what the size will be, etc.

0:15 – 0:50
After I determined what diameter I wanted for my arc reactor, I began cutting out the outer ring (toroid?). This is the primary defining feature of the arc reactor so get it right. I roughly cut out a lumpy round shape with a saw from my rectangular slab of plexiglass and sanded it down with a Dremel. I periodically compared its shape with something I knew was round (the inner cardboard tube of some tape), and marked irregularities with marker. I sanded those down and repeated the process.


When I didn’t dare sand any further with the Dremel, I switched to manual sanding. I bent some sand paper into a round form using that same roll of tape from earlier, and sanded until I felt uniform resistance all around the perimeter of the plexiglass… and it looked round. Then I buffed the edges with a headlight polishing kit, and if you don’t have one, just use progressively finer sandpaper (probably 400-600 grit).

0:51 – 1:12
I made a little cardboard template to help me trace out the inner circle I wanted to cut out. Basically I took the corner of a tissue box, and punched a hole two and a half inches or so from both sides. That way I could just stick a marker in that hole, spin the plexiglass around, and auto-magically draw a circle. (you can see it kind of below)

I didn’t have a hole saw, so I just perforated plexiglass prodigiously with my drill until I could use snips and fracture the remaining plexiglass ribs keeping the center in place.

1:13 – 1:25
More sanding with the Dremel and around a round form… I found that a can of bug spray was pretty close to the diameter I wanted, and the cap was slightly tapered, so I could work my way down it.


1:25 – 1:35
Not much going on here. Just liberating the wire mesh from an old computer speaker, and harvesting some LEDs from a cheap Harbor Freight flashlight. (cheap… H.F. …redundant, I know)

1:35 – 1:45
Here I’m fabricating a ghetto circuit board from some CD spindle spacers. I roughed up the surface with some sandpaper so that it would diffuse light better, and so that crazy glue would get a better purchase on it.

Overlaid on template...
Overlaid on template…
Ghetto LED array.
Ghetto LED array.

Oh, and I also patched the middle hole with another piece of plastic.

1:46 – 1:48
My friend is a chainmailer, and bought some square stainless steel wire. I stole a length of it and cut segments to make some improvised surface details on the prop.

1:48 – 1:50
Since I didn’t have any sort of cast, or CNC’ed, or 3D printed piece to use for the center reactor scaffold-y bit (and I wanted to get that detail visually accurate), I called upon papercraft hacks. All you need is a 2D object that looks close enough to pass a brief inspection. So I cut out the desired shape, laminated it (for a cheap pseudo-metallic gloss), and taped it to a clear plastic substrate for strength. You could try metalized paints on paper for a better effect.

1:50 – 1:56
I added in the mesh I cut from the computer speaker in the middle and wired up the LED’s.

1:56 – 1:58
Upper left: I glued in the square-wire segments I cut earlier to define the borders of the 10 transformers/electromagnets on the arc reactor.
Upper right: I wrapped the sections in duct tape to minimize light leak. You should use electrical tape instead…
Lower left: Wrapped the sections with copper wire. You might want to look up “magnet wire” from radio shack. It’s thinner, and has a reddish lacquer coat usually, which is more accurate.
Lower right: A few more flourishes on the center piece. I bent some thin tin strips (you could cut up a soda can) into a “U” shape, and glued on the head of a screw. This gives it a slightly beefier look, instead of floating in the middle of the arc reactor unsupported.

1:58 – 2:01
Upper left: I sliced off the tips of the LEDs with a Dremel cutting disc to diffuse the light, and glued in small wooden spacers that the copper windings would rest on.
Upper right: Some more spacers to glue the “U” tabs of the center piece to.
Lower left: A wooden back plate for final mounting, with a slot cut to hook up power.
Lower right: What the back plate conceals, the wiring as well as a simple header for power. Thick foam tape (used to hang up whiteboards and such) was used to hold the LED array to the back plate. I went with this stuff because it has a little bit of give, the adhesive will make better contact. Supplement with a dab of super glue and it should hold up reasonably well.

2:01 – 2:05
I cut some slits into the back plate to accommodate 1″ nylon straps. You can get this stuff on Amazon, or a craft store. Also get buckles and tri-glides (those things that let you lengthen or shorten the straps).

2:06 – 2:10
I made a custom battery pack to power my arc reactor. I wanted a nice compact package, and the LED’s needed about 5 volts. So I picked up a cheap 3-battery holder (I usually make a couple purchases a year from Tayda Electronics to make shipping economical), soldered in a switch, and put a small resistor in series just to be on the safe side.

2:11 – End
Finished prop, hooked up, and with some lame pictures of it in action…



Materials Used:
Acrylic Sheet, 1/2″ Thick
Copper Wire (magnet wire @ radioshack)
1/16″ Square Wire (For random decoration, optional. Just improvise otherwise.)
Scrap wood, plastic (for spacers. I used popsicle sticks since they’re thin and have a consistent thickness…)
Clear plastic dividers from a CD spindle (but any rigid plastic sheet would work)
White LEDs (they’ll take on a blueish tint in-camera, as is)
Wire (stranded or solid is fine)
Nylon Straps, 1″ wide + Triglides & Buckles (available at craft stores or Amazon)
Paper (to fake the features I couldn’t make…)
Steel grill/mesh (mine was from an old speaker)
Duct tape, crazy glue…
Foam tape (as a sort of adhesive filler material for imperfect surfaces)

2 thoughts on “Arc Reactor Construction Montage Instructional Companion Post

  1. Hello Sir,

    I’m a fan of Iron Man and I want to make an arc reactor.
    Your project are super and try it again.
    Could you give me the diameter of the circle inside.

    thank you in advance

    Mister Smeyers

  2. The overall diameter of the arc reactor is 3 inches, and the radial thickness of the ring is between 1/4 and 3/8″ (i.e. inner diameter 2.25-2.5″). The real prop’s outer ring is skinnier than mine so just pick the dimension that looks best to you. The inner black disk is about 1.5″ in diameter. Good luck, have fun.

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