You need a flashlight. So, you tear the entire house apart until you finally find one. You go to flip the switch and no light comes on. Checking the battery compartment, you remember that you had to repurpose the batteries for your TV remote. Next, you tear the house apart a second time looking for a couple of batteries.
No longer do you need to go through this destructive process. Thanks to Instructables user Brunoip, you can build your own crank-operated flashlight without batteries. It may not look pretty, but it gets the job done.
You’ll need a handful of spare parts for this project. This includes a small stepper motor for creating energy and a large pile of capacitors. Other materials include cardboard, a small piece of plastic, LED lights, and spray paint.
The capacitors were pulled from a couple of old PC motherboards. In total, Brunoip used 40 capacitors. They were placed in four rows of 10 capacitors each and then soldered together.
After connecting the capacitors together, you’ll create a box out of cardboard. Draw the box out on the cardboard, trim the excess parts, and then fold along the lines. If you decide to check out the full project, you’ll find a downloadable PDF template for creating the box.
Once the cardboard is cut, folded, and taped, it’s spray painted. Brunoip painted his black. Obviously, you could choose another color. The spray paint helps to seal the box, preventing moisture from getting in and making the flashlight look a little more presentable.
Next, it’s time to prepare the motor connector. The four diodes are soldered to the contacts of the individual coils of the motor. A small piece of wire connects the four coils.
At this point, you can start putting everything together. The output of the four diodes on the motor connector is soldered to the positives on the capacitors. The wire from the motor connector gets connected to the negative. The entire contraption is placed inside the box.
A plastic holder is cut out to hold the LED lights. This piece of plastic should fit the front of the cardboard box. Two holes are placed for the LED holders. Resistors are soldered to the positive terminals on the LEDs.
A zip tie is used to attach the motor to the cardboard box. The motor is then connected to the capacitors. You’re almost done with the project at this point.
The last step is to create the crank handle. A small piece of plastic with spacers seems to do the trick. The handle is connected directly to the motor using paste.
Assuming everything got soldered correctly, you now have a hand-crank LED flashlight. The perfect tool to take camping or hiking. Or, keep it around in your garage for a spare light.
Good luck on your project. Have fun building your own flashlight. If you’d like to take a look at the detailed instructions, then visit Instructables and read the entire step by step guide for building a crank-operated flashlight from Brunoip.