It is always a good idea to have bulk food supplies available in case of an emergency. There are a couple challenges to keeping a well stocked emergency food supply. One challenge is how to minimize the space required to store the food supplies. Another challange is how to turn over your emergency food supply. Ideally you want to eat the oldest items and replace them with new items. Without a good strategy for turning over your food supply you could (and probably will) end up with a lot of expired food.
Canned goods make good emergency food supplies. The shelf life of most can goods is in excess of a year and most can goods can be eaten cold. There are a couple issues with storing can goods. First, most commercially available metal or plastic shelving has a shelf space of 12-18". Even stacking cans 2 high leaves a lot of unusable space above the cans, and cans stacked 2 high are unstable without some base material (such as cardboard) between them. Bumping the shelving can cause cans to fall and become damaged, significantly shorting the can's shelf life. Another issue is turning over your can stock. Ideally you would use the oldest cans and replace them with new cans. Minimizing the unusable space above the cans makes it a pain to get at the oldest cans which typically end up at the back of the shelf when fresh stock is place in the front.
This is where the gravity fed can FIFO (First In First Out) helps. The can FIFO works by dropping new cans in the top which work their way to the bottom (via gravity) as the oldest cans are pulled out the bottom. There are many different commercially available can FIFOs typically made of plastic or plastic coated wires. I found the commercially available can FIFOs to be very cheep in construction and some what expensive at $1 or more per can stored. Additionally, I did not find any FIFO can storage systems that would allow the area above the cans to be used without iminent collapse of the cheep plastic. Thus, I decide to make my own.
NOTE ABOUT THE AUTHOR and THIS PROJECT
I am not a wood worker by trade or by hobby. I have hacked many functional items from wood, but do not have extensive wood working tools or training. I would be very interested to hear how this project could be made better from individuals with more wood working experience. Ultimately, the can FIFO presented here, though not a work of art, is very strong, functional and can be made with some simple wood working tools.
This project requires the use of tools. You can hurt yourself with tools if not used correctly. By attempting this project you are taking sole responsibility of your actions. The author holds no responsibility for any positive or negative consequences of your actions if you attempt this Instructable. Use your head, if something does not seem safe DON'T DO IT! If you fail to use your head and things go bad, then man up and accept responsibility for your actions. I HATE HATE HATE that I even need a disclaimer but we live in a litigious society for better or worse (mostly worst IMHO).