Introduction: Mk.1 Arc Reactor Replica

About: Freelance mechanical engineer from the Bay Area.
This post documents my first attempt at building the Arc Reactor from the Iron Man movies. Specifically, this is the MK1 Arc Reactor, the one that Tony Stark makes in the cave in the first movie. Out of all the different versions of the Arc Reactors in the four movies, this one is my favorite. It looks awesome, yes, but it also looks like Tony Stark actually built it, which is something that really can't be said for anything else he supposedly makes. Whereas his other versions and his suits look like the equivalent of Apple products, the MK1 Reactor has copper wire-coils, visible solder joints and screws, some irregularities, etc, all of which make it seem more realistic.
Anyways, the following events inspired me to do this project:

I was sort of at a loss for what to get my dad for his birthday. He always talks about wanting a mill or lathe for our garage workshop, but those are a little out of my price range. Recently I saw Iron Man 3 and realized that my dad is basically Tony Stark. First of all, my dad's name is Tony, and more importantly he also loves designing and building things in his personal workshop. Then I stumbled upon this amazing post by Instructables user Gordon Gekko. His replica of the Arc Reactor intrigued me so much that I wanted to make my own, and what better excuse to make one than for my dad's birthday! 

Gekko's replica is amazing. He used Inventor to make a model of the Arc Reactor that could be laser-cut out of standard thicknesses of plastic, and then all he had to do was paint and assemble the pieces. However, he didn't include a link to the model he used. So, with the help of pictures from Gekko's post and many other images I found online, I created my own SolidWorks model, again only designing parts that could be cut out of either 1/16, 1/8, or 1/4 inch thick acrylic.

Overall, this post has all the instruction and everything you need (minus a laser cutter, some paint, and some glue) to make your own arc-reactor!

I've attached several of the pictures I used as reference, a great SketchUp model from the Replica Prop Forum made by user Cad110, my SolidWorks model, and also 2D vector drawings from my model which can be sent directly to a laser cutter.

  • My SolidWorks Model (.3ds, .stl, .obj, .ply, solidworks)
  • 2D Vector Drawings (illustrator, .pdf, .eps, .svg)
  • Cad110's SketchUp Model 

Step 1: Design

Like I said, I used the images from Gekko's post and other pictures I found online as the concept art for the model I made. However, first I did some full-scale sketches to get all the dimensions to line up with each other. 

Once I drew the sketches, I used my calipers to take measurements right off of the drawings. This process took several hours because I had to do several different views/angles to get 3D dimensions for each part. Once I had all the dimensions, it only took about 3 hours in Solid Works to get the basic components made, and then another couple hours of tweaking to get everything to fit together nicely in an assembly. 

Make sure to note the part names in the last photo. I'll be using these to reference the different parts in the post.

Step 2: Laser Cutting

I ordered all my acrylic plastics from E-Street Plastics (great website) for around 20 dollars, with extra factored in.
My order:
  • 1/16" thick clear -  for the majority of the parts.
  • 1/8" thick black - will be used for some of the rear cage pieces and the mounts that attach the reactor to it's casing/tube thing
  • 1/8" thick milky-white - will be used as the diffuser between the LEDs and your eyes. This is to even out the light and also prevents blindness.
  • 1/4" thick clear - will be used for the main clear-blue magnetic-coil ring thing. (I'll cut out three pieces of 1/4 and stack them to get a ring 3/4 inch thick).
I didn't know this until after I finished modeling, but apparently they only sell 1/16-inch thick acrylic in clear. I'm going to paint everything anyways so it doesn't matter, but it will just be strange assembling a clear arc reactor...

For each part, I exported .dxf files from SolidWorks (these are just vector files), then I opened them in Adobe Illustrator, copied them,  and nested them all together according to what type of plastic they needed to be cut from. I ordered 4 types of plastic, so I had 4 Illustrator files.

Again, these files are available for download here.

Once I had my plastic, it was time to start laser cutting!
Im currently an intern at Instructables, so I was lucky enough to get to use their laser cutter to cut all my plastic. It was a simple matter of copying over the files, doing some test cuts to make sure the laser settings were correct, and then I cut out my pieces! 

I removed the paper backing on the acrylic before cutting out some of the tiny parts because I was afraid I would break the plastic while trying to take the paper off. Usually this is not a good idea because the laser can bounce off of the bed below the plastic and you get melt marks in the bottom of your parts.

A Note on Laser Cutting 

Ideally, after I exported the 2D vector drawings of each piece, I would have adjusted the dimensions to account for the kerf of the laser. This way, when all the pieces have been laser cut, they will all fit together just like they do in the 3D computer model. However, since I’m lazy, I didn’t make those adjustments, and so I laser cut everything and just sort of prayed and hoped that the joints wouldn’t be too loose.

If you are a little confused about when I’m talking about “kerf”, read this paragraph. So in the vector drawings, the lines that make up the boundaries of each part are infinitely thin. However, the laser on the laser cutter has some diameter, and when it cuts a straight line in acrylic, it blasts or burns some acrylic material out. The resulting cut is therefore not infinitely thin, and the width of the cut is called the “kerf”. So, if you center the laser on an infinitely thin line, and then make a cut, the pieces will be a little bit smaller then they are in the vector computer file. Most of the time this doesn’t matter, because the laser dimeter is very small, but if you are trying to build interlocking pieces and joints on a small scale, which I am, then you may have to take this “kerf” into account.

So, I was a little worried when I test fit the rear-cage together, but it ended up not being too loose, and I was still able to get everything assembled without it completely falling apart.

You can see the gaps in the interlocking pieces in some of the close up photos. These gaps are not there in the computer model but they show up in the physical model because of that kerf thing.

(If you want to spend the time to tweak the vector drawings accordingly, then please go ahead! And attach a link to download them in the comments!)

Step 3: Initial Assembly

Most glues dissolve paint, so I decided to do as much of the assembly as possible before painting. 

Rear Cage Assembly 

After some thought and a couple failed approaches, I found that cutting a strip of paper, rolling it up, and “pressure fitting” it inside of the cage-rings was the best way to keep them concentric and aligned correctly. I used a bit of tape to hold the top ring to the edge of the paper. Then I went around, one by one, gluing the thin cage bars to the two rings. Once those were dried, I removed the paper and glued the thick cage bars in. For all of the acrylic gluing I’m using a liquid acrylic glue that melts the plastic together. It’s great because it’s easy to apply and dries in minutes. It took about an hour and a half to glue the whole cage together.

Bezel Assembly

The bezel was fairly easy to assemble. I just had to line up the three holes in each part and apply some glue. I also took some black 8-32 socket head screws, cut off the majority of the threads with some bolt cutters, and used those for the screws in the bezel. Since I want the screws to maintain their cool metallic finish, I glued them on after I painted the rest of the bezel.

Concentric Rings Assembly

This was probably the most tedious part. Since all the dimensions got smaller, the rings wont sit flush up against their mounts, so I knew I was going to have to get the placement on each ring right by just using my hands and my eye. I didn’t actually have the base plate cut yet, so I had to improvise by using some styrofoam and poking the three “staircase” mounts into that, then taping them down so they didn’t move. Then I put one ring on at a time, lined it up, and glued it in place. What I didn’t know is that the glue dissolves the styrofoam, so if I put to much on (which I did) it would drip down to the base of the mounts and start melting the styrofoam, which made everything less sturdy and ahh, was very nerve-racking. I think they turned out okay, but I may need to cut more and do it again if they don’t look good once everything is assembled. If that happens though it’s not a huge deal.

Step 4: The Mag-Coil Ring

This step is sort of optional. It really depends how determined you are to get the color of the mag-coil ring correct. As you can see from the concept art, the ring is a transparent blue-green color, and the problem is they dont really make acrylic this color. If you want, you can cut three 1/4" clear acrylic rings, and just glue those together and use that, which will look great but not perfect. 

The other way to do it is to cast the ring out of resin or epoxy, and add dye to get the color right. At Tap Plastics I bought some clear epoxy for casting and some resin molding supplies, as well as blue and green dye. 

Next I assembled the mag-coil ring by stacking and gluing together the three pieces of acrylic, but then instead of using this as the final part, I used it to make a mold for the epoxy. 

I put the acrylic ring at the bottom of a tupperware container and then poured the molding resin over it so that it was covered by about 1/8 inch of resin. I probably should have used more to get a thicker layer on top, but that was all I mixed and I didnt want to make more (haha). Once this has dried (24 hours), pop out the mold and carefully remove the acrylic piece. Now you have a negative mold of the mag-coil ring.

Next, prepare enough of the clear epoxy in a clear container, and slowly add blue and green dye until the color looks right (I used 2 drops of green and 1/2 drop of blue in 1/2 cup of epoxy). Pour this into the mold and wait for it to dry (another 2 days). When you pop it out, you should have a part that is the same shape as the acrylic piece you made earlier, but it should be the correct color!

Step 5: Painting

The next step was to paint everything. Since I was going to be glueing things together after, and since paint and glue dont go super well together, I left the bottoms of as many pieces as possible un-painted. 

Since there is going to be bright light behind most of these pieces, and since you don’t want that light shinning through the pieces, you have to layer up a lot of paint in order to make clear acrylic completely opaque. After two coats of black on the rear cage, it looked fine, but if held up to the light you could clearly see that it was lightly painted clear acrylic. So, I ended up doing 5-10 coats of matte black for the rear cage, bezel, concentric rings, and mag-coils. Thankfully I used a fast drying spray paint, so it didn’t take that long.

The rear cage just had to be black, so the painting was done for that part.

The center ring of the bezel had to be silver, so I used masking tape to mask off everything except the ring, and then I did about 4 coats of a metallic silver.

The mag-coil pieces also had to be silver, so I also did about 4 coats of paint on these.

The concentric rings had to be gold, but their mounts had to be black. I decided it was better to spray the whole thing gold and hand paint the mounts black as apposed to vice versa. I put 3 or 4 coats of metallic gold on the top and sides (not the bottom cause you’re never going to see that), and then I used a small brush and a pool of matte black spray paint to paint the mounts.

Protip: If you ever need to hand paint with spray paint, fold up a paper towel, put some masking tape on it, and then shoot some spray paint on the tape until it pools up. This works as a great disposable pallet for use with a paint brush.

Step 6: LED Package

I laser cut a disk out of 1/4 inch clear acrylic and made it a little smaller then the diffuser plate. I also put twenty three 5 mm holes in the plate to mount the LEDs. The holes were cut just right so I could pressure fit the LEDs in without glue. Then I soldered sets of four LEDs together in series, and had one set of three (because 4 doesn't go into 23 evenly). Then I added appropriate resistors to each LED circuit and soldered those circuits together in parallel. 

While I had my soldering iron out and hot, I also made the plug for the 12 volt DC adaptor that I'll be using to power the LEDs. 

I tested how the LEDs would look behind the diffuser, and realized they were way to bright and to "focused". I fixed this by cutting a second diffusing plate out of the same milky white acrylic, and stacking the two plates on top of each other to diffuse the LEDs more. 

Also, the LEDs stick up from the clear plate they are fit into, which means it will be hard to glue that plate to the back of the diffuser. So, I cut a small spacer ring to glue between the LED plate and the diffuser. 

Step 7: Intermediate Assembly

At this point, most of the assembly could be finished.

Front Assembly

In this step I assembled everything together except the rear cage. First I glued on the three socket screws to the bezel.

I bought a small piece of screen-door metal mesh stuff and cut a small circle out of it, then glued this down to the small disk of translucent white acrylic that fits in the center of the diffuser. It took a little work with a file to get it to fit beneath the smallest of the concentric rings.

Next, I glued on 9 small black capacitors to the diffuser using super glue. I think they were 10 µF.

Then I glued the concentric ring assembly to the bezel, and then that onto the milky-white diffuser. I glued the LED plate and that small spacer ring to the second diffuser, and then I glued the that assembly to the rest of the front assembly. 

Mag-Coil Assembly

Since I didn't want to melt any of the paint off of the mag-coils, I just used a little super glue to attach them to the mag-coil ring. Once all 10 mag-coils were glued in, I ran two pieces of gold wire around the circumference of the ring (see photos). I attached them with thin pin-stripe tape just to hold them down temporarily. Then I wrapped each mag-coil with thin copper wire, wrapping the wire over the thin gold wire. In reality, the gold wires are soldered on individually, but that would take a lot of time and patients and might also heat up the plastic too much, ruining the paint job. The method I used creates a very similar effect for much less work. If you want, you can even dab hot glue where the solder joints should be, and then paint them silver so they look like tiny pools of solder.

Step 8: Display Stand

The display stand in the movie consists of a square base, a pipe support that extends from the base to the reactor, a tube that encloses the whole reactor (this is where the inscription is written), and a glass case that covers the entire assembly. In my version, I didn't want to have a clear case over it, which also meant the base could be a little smaller. 

The Base

I made the base out of a 1 inch thick piece of wood. I cut it into a 3.5 inch square and drilled several holes in it to fit the power plug and support pipe. I used 1/2 inch PVC tubing for the support pipe. I didn't have a drill bit that was exactly the right size for the pipe, so I over drilled it a little, wrapped the bottom of the pipe in tape so it would fit snugly, and then laser cut a piece that fit tightly around the pipe and covered up the gap. 

The Mounting Tube

The mounting tube is the section of pipe that surrounds the arc reactor and has the attachments that connect to the support pipe and base. 

Step 9: Final Assembly