Make an Iron Man Arc Reactor

I didn't have a lot of time to make a great Halloween costume this year so I figured I'd do something relatively simple that was still eye catching and cool. I wanted my Arc Reactor to look pretty realistic, but not necessarily 100% movie accurate, so it's kind of a cross between a MkI and MkII version. There are some things I'd change on the next version (and I'll point them out) but overall I'm pretty pleased with it.

The reactor is attached to an old heart rate monitor strap and it's powered by a 3 volt battery pack that just slips in my jeans pocket. It's light weight and is comfortable to wear for several hours at a time. In the photos below you can see how bright it is- it easily shines through my t-shirt under normal office lighting conditions and is very bright at night.

Follow along and see how it's made.....

Update: see page six for the new style reactor!

Another update! Many people have asked for a kit and a fellow RPF board member has produced a fantastic kit and said I could post a link. This is a very nice kit for anyone wanting to build a wearable arc reactor-
http://www.therpf.com/f13/wearable-thin-iron-man-arc-reactor-kit-147966/

Step 1: Tools and materials

There are a few necessary tools:
soldering iron
dremel tool
drill bits
metal snips/shears
jeweler's saw (or some kind of saw to cut metal and plastic)
needle nose pliers
wire cutters
files/sandpaper
glue gun

And for materials:
thin brass sheet
plastic sheet ( I used Delrin- you can buy Delrin and acrylic sheet from Colorado Plastics)
clear acrylic sheet
copper wire- 22ga and 24ga thickness solid wire
sheet metal- 22ga thickness (.025in or about .5mm thickness)
PCB (printed circuit board)- at least 4" square (Radio Shack sells some that measures around 4.5" x 6")
several small bolts - I used 10ea 2.5mm bolts and 3ea 3mm bolts w/nuts
3 volt battery
11 ea NTE30027 surface mount LED's - I bought them from a local supplier but you can order them here: http://www.cablesandconnectors.com/30000-30.HTM
battery hook up wire

As an option for LEDs and making a circuit board you could use these instead-
http://www.sparkfun.com/commerce/product_info.php?products_id=8735

I'll make specific notes about the materials used and possible substitutes/workarounds on the specific construction pages.

Please note: be careful cutting sheet metal as the edges can be very sharp and it's pretty easy to cut yourself.

Comments

[gcharlow]

But that would mean there is two wires from the etches and one for the center, I'm really just confused on how the center works with the whole thing

[Honus]

You're over thinking it. It's very simple- all of the LEDs are connected in parallel. Because of this you need one wire for positive and one wire for negative to connect the center LED to the outer LEDs. Does that make sense? Then you need two more wires to the center LED to connect your battery. The power then flows from your center LED to the outer LEDs.

A solder pad is just the copper part that the LED is soldered to.

[gcharlow]

Oh and how do u make a solder pad

[gcharlow]

or do I not need one

[gcharlow]

Thank you, I accidentally already did it chemically and am curious of how to make one trace positive and the other negative. Also on your second paragraph u say that I drill holes in the traces and that those wires connect to the battery, I've read that paragraph over several times now and am still confused

[Honus]

I don't understand what you are saying. You don't make the trace "positive" by etching it. You make it positive or negative by the way the battery is connected to it.

The second part is easy. Drill a hole through the copper trace. Insert a wire through the backside of the PCB and solder it to the trace. It doesn't get any easier than that.

[gcharlow]

i am so much more confused now, on the diagram you have a battery but in the pics you have a wire connecting it to a battery pack, can you please explain to me what to do in great detail

[Honus]

You have a positive and negative copper trace for the positive and negative LED solder points. I cut the copper traces using a Dremel tool- I did not etch them using chemicals. The positive and negative traces of the outer LED ring are connected to the positive and negative traces of the center LED using two pieces of wire that are on the BACK of the PCB. These are clearly shown on the LED wiring schematic. You simply drill holes through the traces, poke the wire through from the back of the PCB and solder it to the copper on the front.

Now drill two more holes through the traces for the center LED- one for positive and one for negative. Insert two wires into these holes from the back of the PCB and solder them to the traces- these are the wires that go to your battery. Again, this is shown on the LED wiring schematic. Does that make sense so far?

Regarding using resistors: the first reactor I made did not use resistors and the second reactor I made did use resistors. On the first reactor the battery voltage for the battery (single cell LiPo) I used was 3.7V and the forward voltage drop of the LEDs used is between 3.5V and 4.0V so the resistor value would be between 1 Ohm and 10 Ohms- a very low value so I elected not to include them.

On the second reactor I made you can see there are 100 Ohm resistors soldered on the copper traces. In this case I used resistors because the power supply I was using output 5V, which is a bit higher than the forward voltage drop of the LEDs. So let's say you wanted to power your LEDs using 3 AA batteries. If you are using alkaline batteries your battery voltage would be 4.5V- you could probably get away without using resistors but you would probably burn out the LEDs pretty quickly (exactly how long I have no idea.) If you used NiMH batteries your voltage would be 3.6V and your LEDs would last longer. If you tried to use a 9V transistor battery you would fry your LEDs.

The bottom line is that adding resistors will lengthen the lifespan of your LEDs and they are an absolute must if your battery voltage is higher than your LED voltage drop. While you can get away without using resistors it is considered proper practice to include them. If you look at the resistor calculator page I linked to it shows you how to wire the LEDs using resistors. This is also shown on the new style reactor page- you can see where the copper traces are cut that allow the resistors to be soldered to the LEDs.

[gcharlow]

ok so i have done the inner ring assembly. now i have to do the backplate. I am a litttle confused. I know how to ectch the traces with the printing and ironing and soaking and acetone, but i am confused on how the circuit works. So can you please give me a detailed step by step of how to wire through the back and how to solder the Leds, like why do i need a solder pad for the center and not the outside ones, or do i do that too. And how does the center led connect to the outside ring LEDs and what is the wire you show in the picture. im confused and do i need a battery pack. Please give me a detailed step by step for this part and please give me a list of any addditional tools i need for this part. Thank u

[gcharlow]

can u please answer the question above

[gcharlow]

and your etchs dont look ike you used the whole process with transfer paper and such, what process did u use, pleasseeeeee help

[gcharlow]

wait please help... i am confused, the schematic says i need resisitors, but you are saying i don't, so should i just do what you said, and also how does the wiring in the back connect to the center i cant tell on the diagram and its covered up in the picture. and third where do i connect the battery pack to

[gcharlow]

is there an etching connecting the inner led to the outer led, please add the schemetics so that I can print it on transfer paper and etch it

[Honus]

Sorry- I've been out of town and I'm headed back out today for a three day business trip.

There isn't an etched trace that connects the inner LED to the outer LED ring. If you look at the photos there are wires on the back of the PCB that connect the traces. This is shown on the wiring schematic.

[gcharlow]

a schematic of the circuit board and all of its componeents

[Honus]

Also, if you look at the new style reactor you can see I added resistors for each LED on the board. The resistor value depends on your supply voltage. The NTE 30027 LEDs are rated at 20mA and 3.5V drop. Since I was using a single cell LiPo to power it the resistor value was so low I didn't include one on the first reactor I made- ideally you should always have a current limiting resistor or you will eventually burn out the LED. That's why I added them on the second reactor I made. You can calculate the resistor value for the battery you want to use and print out a wiring schematic here- http://ledcalculator.net/

[gcharlow]

is there an etching connecting the inner led to the outer led, please add the schemetics so that I can print it on transfer paper and etch it

[gcharlow]

how did you cut the acyrlic ring

[Honus]

I cut it with a scroll saw and then sanded it smooth.

[spoovendra]

Are your measurements in inches or milimeters?

[Honus]

As stated on Step 2: All the measurements used in the drawings are in inches and they are really just to be used as a guide- I really just eyeballed everything as I was making it. By no means are they meant to be exact measurements.

[spoovendra]

Do you think that these dimensions are enough for the whole Reactor?
Brass sheet 22ga thickness (.025in or about .5mm thickness) – size 250mm x 200mm
(ABOVE: Subsituting the inner ring(spider webs) from steel to brass)
Steel sheet 22ga thickness (.025in or about .5mm thickness) – size 200mm x 200mm
(ABOVE: It is for Step 4)
Are these OK?

[Honus]

I don't know- you would have to lay everything out and see if you can make it fit within those dimensions.

[spoovendra]

How did you attach or affix the Arc Reactor to your chest?

[Honus]

I use an old heart rate monitor strap- it's shown in the instructable.

[spoovendra]

What type of battery did you use for the 3V battery?

[Honus]

I used a single cell LiPo battery but two AA batteries would work just fine.

[spoovendra]

How thick must the acrylic be?

[Honus]

It's shown on the drawing.

[spoovendra]

Can I use friendly plastic pallets to form outer ring?

[Honus]

Sure!

[spoovendra]

How much thick must the brass sheet be?

[Honus]

It doesn't really matter. The brass sheet I used was really thin- you could easily bend it with your fingers.

[gcharlow]

what did you use to cut the aluminum ring out of the block and make it all smooth, can you please give me a step by step u used to cut the ring of of a block

[Honus]

I didn't cut it from a block of material. I cut it from a scrap piece of thick walled Aluminum tubing using a lathe. You could cut one from a piece of PVC pipe and shape it with a dremel since you don't have access to a lathe.

[gcharlow]

well i already ordered the aluminum ring, what if i just made the aluminum ring go over the side of the copper plate a little, would that still work

[Honus]

You can do that but you will have to adjust the size of the inner ring assembly in order to make it fit within the smaller diameter.

[gcharlow]

what are the dimensions of the brass tabs

[Honus]

There aren't any- it's not critical. Just make them to fit.

[Tidus-74]

Ok thanks ! And Wich means did you use to bend the part in this step ? (spider top view)