A fun & whimsical way to collect donations for a variety of causes. Depending on the materials you have lying around your house, this machine can be built for free! Even if you have to buy all the materials, maximum cost is less than $15.
This is a minimalistic and easy design for makers of all experience levels! The whole machine takes about an hour to build.
1. Cardboard Box (not pictured)
Medium to small, somewhere around 12 in. x 12 in. x 12 in.
2. DC Computer/Electronics Fan
Recommended to harvest one from broken electronics equipment. Otherwise, these can be purchased online from a variety of manufacturers for ~ $5. Here's one website.
3. Power adapter cord (120 VAC to ~ 12VDC)
Recommended to repurpose an unused power cord lying around; old charging cords (e.g. phones, cameras, etc.) are perfect.
4. Saran Wrap
1. Wire strippers
3. Soldering Iron*
4. Hot glue gun
5. Duct Tape (or other heavy duty tape)
*If soldering iron isn't available, tightly twist wires together and coat in hot glue.
Build it! Pt. 1
Optional: Spray paint, or paint, cardboard box.
1. Cut a 3 in. x 1 in. slot in the top of the cardboard box.
2. Cut windows into the 3 of the sides of the cardboard box.
Be sure to leave at least 1 - 2 in. of cardboard along the edges of each side.
3. Cut the remaining side into a door.
Cut along 3 of the edges (bottom, one side, and top) so that this side opens and closes, with one of the edges as the hinge.
4. Tape saran wrap on the inside of the cardboard box to cover the window holes.
Tape saran wrap onto the farthest most edge. Pull one side of the saran wrap tight and tape to box. Repeat with remaining sides. If there are loose areas, gently pull up tape and re-adhere to box.
Build it! Pt. 2
1. Cut connector ends off of the computer fan and the power adapter and strip wires.
For the computer fan, strip the red and black wires.
For the power adapter, separate the two wires and strip.
2. Connect the red computer fan wire to one lead of the power strip, and the black computer fan wire to the other power strip lead. Check that the fan turns on when the power adapter is plugged in.
3. If fan turns on, unplug the power adapter and solder the connections together. Coat in hot glue.
Build it! Pt. 3
1. Glue computer fan on the inside of the cardboard box, in the center of the side with the door.
2. Cut a hole in the center of the cardboard box door to expose the computer fan.
3. Cut a top vent in the cardboard box door.
Recommended to cut small slits, or cover larger vents with skewers or toothpicks.
4. Adhere the cardboard box door to the side.
I found strips of velcro lying around. Other ways to adhere are rubber bands, string, or just hot glue the sides together.
Test & Impress!
Add a few dollar bills to check that there is good airflow. If it works as expected, use at parties as a fun way to collect money for food + drink, or incorporate into your next fundraiser to collect donations!
If you notice that the dollar bills are getting stuck in the corners, add some angled cardboard rectangles or increase the size of the vent.