Introduction: The Glowing Briefcase From Pulp Fiction
Pulp Fiction is considered by many to be one of the greatest movies of all time. One element that is central to the story is the mysterious briefcase. It contains an unknown treasure that glows whenever the briefcase is opened. I thought that this was an interesting prop. So I decided to make one.
In this project, I am going to show you how to make a glowing briefcase like the one in Pulp Fiction.
Step 1: Research: Find Reference Pictures of the Prop
When, trying to replicate a movie prop, the first step is to get good reference pictures of that prop. Usually, this involves playing the movie on your computer and taking a large number of screen captures of relevant scenes.
You should also search the internet for resources that may have been put together by other people working on similar projects. One of the best resources for movie props is the Replica Prop Forum. As an example, here is a thread that discusses this briefcase: http://www.therpf.com/f9/pulp-fiction-briefcase-functional-light-effect-ideas-127915/
Step 2: Materials
Normally Closed Momentary Switch
Insulated Copper Wire
3 AA Batteries
3 AA Battery Holders
Heat Shrink Tubing
Female Quick Disconnect Connectors (optional)
Hot Glue Gun
Step 3: Find a Matching Briefcase
The first thing that you need to do is find an appropriate briefcase. The level of accuracy that you want to adhere to is up to you. You can just use any briefcase that you find at a thrift store or you can painstakingly hunt down the exact style that was used in the movie.
If you want to closely replicate the movie briefcase here are some features to look for:
Metal latch with a combination lock and the brand FRANZEN etched on it
Four brass feet on the bottom
The inside of the lid has a solid color fabric backing and is surrounded by black fabric.
Step 4: Find a Good Light Source
In the movie, the light in the briefcase was a plain incandescent light bulb with a colored filter. However, I decided to use an LED light because they are much more efficient. This let me use a much smaller battery.
The LED light that I used was harvested from an old Maglite flashlight. First I removed the reflector from the flashlight. This exposed the LED assembly. Then I unscrewed the LED mounting plate. To do this I inserted small screwdrivers into the holes on both sides of the LED and turned the plate counterclockwise until it came out. I left the LED mounted to circuit board and mounting plate that it was attached to. This made it a little easier to attach new wires and mount it to the inside of the briefcase.
Step 5: Select a Switch
For this project, you need a "normally closed" momentary switch. This type of switch has the contacts connected when the button isn't being pressed and the contacts are disconnected when the button is pressed. This is the same type of switch that is used for the light in your refrigerator.
You can purchase normally closed momentary switched from most stores that sell electronic parts such as Radio Shack. I am using a miniature snap action switch with a long lever arm. This switch has three terminals. One terminal is normally open, one terminal is normally closed and the third terminal is the "common" terminal that the other two terminals connect to.
Step 6: Make a Simple Battery Pack
The light is normally powered by three D size batteries in the Maglite. But I decided to replace them with three AA batteries in order to save space. The AA batteries won't last as long as D batteries, but since this light won't be on very often, I thought that this substitution would be fine.
Each of the batteries is mounted in a AA battery holder. The wires of the battery holders are connected in series (positive to negative) to form a 4.5V battery pack. I then insulated each connection with a small piece of heat shrink tubing. To hold the batteries together, I used hot glue to attach the three battery holders to a scrap piece of cardboard.
Step 7: Connect the LED, the Switch and the Batteries
Take two pieces of insulated wire that are each about two feet long. Then strip the insulation off of the ends. If you are using a pair of wires that are fused together (such as speaker wires), then separate them for several inches at the ends. Connect one wire to each of the terminals on the switch. If your switch has more than two terminals connect one to the normally closed terminal and one to its common terminal. You can either solder the wires to the terminals directly or you can use a pair of quick disconnect connectors.
Cut one of the wires near its midpoint. Then separate and strip the ends. Connect one of the cut ends to each of the two end wires on the battery pack. Once again I used heat shrink tubing to insulate the connections.
Lastly you need to connect the free end of the wires to the LED assembly. Touch the wires to the contacts on the LED assembly to verify the appropriate orientation. In most cases you will want to solder the wires in place to make a good connection. But for a prototype, I just taped the wires in place. That way I could easily make changes later.
Now test out the circuit by pressing the button. The light should be off when the button is being pressed and on when the button isn't being pressed.
Step 8: Mount the Parts to the Inside of the Briefcase
The last step is to mount all the parts to the inside of the briefcase. The simplest way to do this is to just glue them in place. I used hot glue. But keep in mind that this can damage the leather if you are not careful.
The switch was glued to the side of the briefcase. You need to locate the switch in a place where the button will be pressed when the briefcase is closed. I positioned it below the leather strap on the lid. When the briefcase is closed, this leather strap presses the switch and turns off the lights.
The batteries were mounted to the back wall of the briefcase. When the briefcase is carried, this side is on the bottom and the weight of the batteries won't be pulling on the glue joint.
The LED was positioned in the center of the briefcase in order to let the light spread out in all directions.
Step 9: Adjust the Color of the LED
The briefcase in the movie gives off a golden/yellow light. Unfortunately, most LED lights produce a bluish white light. Rather than trying to find an LED with the appropriate color, you can simply change the color of the light that you already have. The easiest way to do this is to just color the surface of the LED with markers or highlighters.
Step 10: Finished Briefcase
Now you have your own mysterious glowing briefcase that you can use to store your treasured possessions. You can use it to carry around your diamonds, your gold coins or the holy grail. Use your imagination and have fun.