This is a small fan that you can put on your desk and is powered solely by the USB port on your computer. This can be made completely from junk and is a great first project for both USB and soldering. It is relatively easy, but some parts will take patience.
Step 1: Gather Materials
These are the parts you will need:
-Small Motor (you can get this from a portable fan)
-Fan Blades (you can also get these from a portable fan)
-USB cable (sorry, the one in the picture is different from the one used later on)
-Case (This is where you get to be creative; see step 3 for more info)
-Knife (any kind will do; you can also use wire strippers)
-Tape (electrical tape is best, but I was out)
-Hot Glue Gun (this is not totally necessary, but it's the best thing for securing the motor)
Step 2: Prepare the USB Cable
I ended up using a different USB cable from the one in the first picture because it is probably much more like the one you will be using. Cut your cable and strip the outer insulation. There should be four or five wires. One red wire, one green wire, one white wire, and one or two black wires. You want one red and one black wire; you can cut the rest off. If you have two black wires, either one will work. Strip the ends of these two wires with a knife or a pair of wire strippers.
Step 3: Prepare the Case
For my case, I used a broken lamp, but it can be anything you want. Some other ideas are a portable fan case, a computer mouse, or even just a wooden box with some holes drilled in it. For me, "preparing the case" meant unscrewing the light bulb, cutting out the socket, removing the top of the case, and pulling out the wires. Then, I threaded my USB cable through the "tube." This was by far the hardest part and took lots of patience. Attach the motor with tape and plug it in to make sure your fan that it is working properly.
Step 4: Solder Connections
First, you need to figure out which way you want the motor to spin. Put on the fan blades temporarily and hold the wires together with your fingers or some tape. If the fan blows air backwards, switch the wires (For me, it was red on yellow, black on white). Solder the wires together and remove the blades.
Step 5: Attach Motor and Blades
I used a hot glue gun to attach the motor, but tape or another kind of glue would work, too. Be sure to attach the motor well! I cannot emphasize that enough. If the motor is not attached well, it will spin out of control, the solder connections will break, and the motor will fall off.
Once you have the motor attached, put on the blades and plug it in.
Step 6: You're Done!
Congratulations, you did it. I hope you like your new USB Powered Desk Fan!