How we Built a Two Bulb Flashlight



By: Izaak Shaker and Bennett Ross

One of the first things that we had to do was to make a shell for the light, but because we wanted to make a flashlight with two bulbs, we couldn’t just buy one online. Instead we decided to 3-D print our shell (outer part), because with the two bulb design, a normal flashlight shell wouldn’t allow us to fit everything. The 3-D print took 15 hours. Since we are at the end of the day, we did not have to wait 15 hours. The next time we went to that class, it was done. We made a mistake, we decided to print the design horizontally, which means we needed additional support. Which is also the reason why the design took fifteen hours to build. Thus, If we had printed vertically, it would only take ten hours. 

We were originally going to do the project, but our parts didn’t come in on time. From this point on, we will describe what we would have done if our parts came in on time. To make a flashlight, we need something to produce light. We decided to go with two L.E.D. diodes, which in other words, is a small L.E.D. light bulb. But we need to make sure that the L.E.D. light doesn’t burn out, therefore, using a resistor. A resistor essentially reduces the flow of electricity passing through the wire. The other things we needed were pushbuttons, flashlight reflector, glass to protect the L.E.D. diode, battery holders, four electrical wires, and four 1” pieces of shrink tube.

(Keep in mind, there are two bulbs. So we needed to do two of everything, even the pushbuttons). The first step we would have done is to solder the resistor to the diode’s anode (short lead), and trim away any excess soldered leads from the joint. The next step is to solder a wire to the battery holder, but you must solder the wire to the side of the holder that has a protruding bump (this side is the positive voltage).

Next solder a different colored wire to the other end of the battery holder, this side should have a little round indent. Next we needed to complete the circuit, so we slid the shrink tube around the one piece of wire that’s attached to the  pushbuttons. Then, take the wire with the shrink tube and slide the other side of the shrink tube onto the cathode (long lead). With the shrink tube on the cathode and the pushbutton wire, heat the shrink tube so that it shrinks around wires. Do that with the other diode and push button also. Once the push button and the diode are attached, we need to attach the other push button wire to the battery holder side that has the indent. Finally, we take the wire that is attached to the battery holder (the side that has a bump), and we solder that wire to the other side of the diode that has the resistor attached to it. 

Now that all the parts are ready and working, we can assemble the actual flashlight. The first thing would be to put all the parts in our 3-D printed shell and glue the L.E.D. diode in place on the flashlight reflector, then glue the reflector into place on the shell. Once the L.E.D. diode and reflector are in place, all we need to do is glue the protective glass in place, and the flashlight is finished.