Shell Lamp Construction

I started this decorative lamp as a birthday present for a friend while I was in Nicaragua over the summer, and finished it after I got back to Berkeley. Here’s instructions on how to build it. The basic idea can fit with any sculpture: take a driver circuit from a flashlight, take the LEDs off, run wires from where the LEDs were to where you put them on the sculpture, stash the circuit inside the base, and add a switch. You can add more LEDs than were originally in the flashlight, and maybe add a plug if you want.


1. The sculpture
1. The sculpture
For this lamp, I made a tree out of galvanized wire. I'll need to explain how to build the sculpture separately. Any type of sculpture will work; the important thing is to run two sets of wires to the LEDs. In this sculpture, the body of the tree acts as the negative wires in the circuit, and a set of thin green enameled wire acts as the positive wires. Together, they will deliver electricity from below the roots to the LEDs mounted at the leaves. The enameled wire is carefully wrapped around the trunk to be half-hidden. Notice that one of the galvanized wire at the roots is sticking straight down, and that the enameled wires are wrapped around it. Those will go into the base of the lamp and will be connected to the rest of the circuit.
2. The LEDs
2. The LEDs
I attached the three LEDs to each place where the leaves will go by wrapping their negative legs around the branches and soldering them on. I made sure that their positive legs did not touch the tree, and soldered the enameled wire to the positive legs. In the lower left you can see a leaf where I haven't yet attached the LEDs.
3. The base
3. The base
In this sculpture, the base is made from white pumice, which is easy to carve but looks like a sturdy rock. You can see how the base holds the switch, as well as a plug for an external 3V power supply. White pumice washes up on beaches on the eastern coast of Nicaragua. They can be also be purchased online. I carved the pumice with a kitchen knife and screwdriver, and had to be careful not to cut too much. It has roughly the same strength as 2-week old bread. The only drawback is that it will conduct electricity, which means you must be careful with your wiring to avoid short circuits.
4. The battery compartment
4. The battery compartment
I carved a compartment in the bottom of the stone to hold the driver circuit, the wiring, and the batteries. You can also see where the switch and the external plug can fit in. The external plug wasn't necessary; I added it so my friend who I made it for could have the choice of plugging it in or running it from batteries.
5. The driver circuit
5. The driver circuit
I salvaged a 3V LED driver circuit from a flashlight that took two batteries. When it lived in the flashlight, 3 LEDs were soldered to a triangular circuit board. I removed the circuit board from the flashlight, and soldered a black wire to where it used to connect to the negative terminal of the batteries, and a red wire to where it connected to the positive terminal. I also unsoldered the LEDs and soldered a black wire to where the negative leg of the LEDs used to be, and a grey wire to where the positive leg of the LEDs used to be. Afterwards, I wrapped it in a strip of newspaper and dripped wax over it to give it padding and insulation as well as to make it waterproof. That last step probably wasn't necessary, and will prevent the circuit from dissipating heat, which may reduce its lifetime. This particular circuit is fairly effecient, so it doesn't generate very much waste heat. My friend reports it still works great after three months of using it several hours most nights, so the wax and paper coating may work out. The important part is to put some insulating layer between it and the base to prevent a short circuit (assuming you use a pumice base).
6. Lampshades
6. Lampshades
I used sea shells for lamp shades and "leaves". The LED clusters will point down and out, and the shells will cover them from the top, so only a tiny bit of light will be blocked by the shells. You can see that each shell is a little bigger or about the same size as the LED cluster.
7. Shell mounting point
7. Shell mounting point
Each branch was made from three strong galvanized wires twisted together, and one thin enameled wire hidden in. The galvanized wires at the end of the branch are bent so they can hold a shell in place.
8. Root wiring
8. Root wiring
Most of the tree's roots will spread across the base to anchor it and for decoration. But one of the galvanized wires from the roots will go straight into the base and be attached to the black negative wire from the LED driver circuit. The four thin green galvanized wires will slip down beside it and connect to the grey positive wire from the driver circuit.
9. All the pieces
9. All the pieces
All the pieces are laid out (except the shells). You can kind of see how they will fit together.
10. Attaching the LEDs
10. Attaching the LEDs
I'm soldering the final LED cluster to the sculpture.
11. Testing the wiring
11. Testing the wiring
It is important to connect the wires and test everything before proceeding with further assembly. The battery pack is on the left, and its positive wire (red) goes through the switch into the power leads of the driver circuit. Its black wire is connected to the power leads of the driver circuit.

This picture is a little confusing, because I used a two-way switch that goes between the battery pack and the external power supply. You can see that the red wire from the external power plug on the right is connected to the other terminal of the switch, and its black wire is connected to the driver circuit. In this test, I was checking the batteries and left the external power unplugged.

In case you don't recognize it, the driver circuit is the grey lump in the middle. The wires sticking out of the top go to the power source, and the wires sticking out of the bottom go to the LEDs. If you look carefully, you can see they are attached to the wires from the base of the tree.

I took this picture after I got the test to pass, and you can see the LEDs are lit up. Short circuits and bad connections are easy mistakes to make. I actually made some short circuits between the enamled wire and the tree by pulling on it too hard and nicking the enamline. Until I replaced that wire, the lights wouldn't come on. I figured out which of the enamled wires was nicked by connecting them one by one, and see which one didn't produce light. If none of them lit up the LEDs, I'd attach an LED directly to the driver circuit to make sure that was working.

12. Testing the switch
12. Testing the switch
I switched it to the external power supply and the lights went out since the external power (top) wasn't plugged in. Good; the switch works.
13. Testing the external power
13. Testing the external power
Now I plugged in the external power supply, and the lights came on. I took the batteries out so you could see that they weren't powering the lights.
14. Attaching the base
14. Attaching the base
I started the final assembly by inserting the tree sculpture into the base, and wrapped its surface roots over the top of the base. Next, I used pliers to bend its root tips and sink them into the base, so that it was well-anchored. I tried dripping solder into the hole of the tap root to make it more sturdy, but that melted the enamel and made a short circuit. It drove me crazy trying to get that solder out. After I finally got it out, I pulled the enameled wire off the tap root and dripped super glue over it to give it a new layer of enamel. I tell you this so you won't make the same mistake.

I wired everything together and put the external plug, the driver circuit, the switch, and the battery holder in the base. I carved every hole to exactly fit its piece, so everything went in pretty snugly. The external power plug was the only thing that was a little loose.

After everything was together and I tested that it worked, I dripped super glue on the pieces that were a little loose. I made another mistake of letting some super glue coat the inside of the plug for the external power supply. Dried super glue is a good insulator, so the electricity couldn't go through until I scraped the glue off the inside of the plug. I went a little crazy thinking of ways to clean it off without buying a new plug. I wanted to roll up a little piece of sandpaper and slide it in and out of the round hole, but I couldn't find any sandpaper and didn't want to go to the store. I finally got an extra piece of galvanized wire and used wire pliers to nick its edges to make it rough and used it as a file. To avoid that hassle, be careful when applying superglue!

15. Attaching the shells
15. Attaching the shells
I slotted the shells in place over the LEDs, and used pliers to gently bend the "twig" galvanized wires in to hold the shells in place. I had to be careful on this step to avoid breaking the shells.
16. Bottom view
16. Bottom view
You can see how the battery pack fits in the bottom of the base. The driver circuit is inside the base, on the other side of the battery pack. I carved the hole for the plug from the other side, so it's recessed a little. I drew pictures of a battery and a wall plug on the switch to explain how to switch it from one to the other. Ideally, I would have used a three way switch so you could turn it off without unplugging it or taking out its batteries. But I had already carved the hole for that switch, and didn't have another piece of pumice to use instead.
17. Lamp with external power supply
17. Lamp with external power supply
I started the lamp in Bluefields, Nicaragua, where I couldn't get an external power supply. It took me longer to finish than I thought, and I ended up finishing it stateside where I could get one. The friend I made it for lives in New York, and normally has no trouble getting electricity, so adding a wall plug seemed like a nice touch. The parts would have cost less than $5 if I hadn't bought the power supply; RadioShack charged me $20 for that piece.
18. El fin
18. El fin