Cardboard will fail if it gets wet, you may want to use thin plywood, or the plastic version of cardboard if you think the units will get wet . These...
I love free stuff from junk. This is a project to give you lots of small parts storage for almost no cost but your effort. The result is a set of ten to hundreds of small part storage containers, perfect for nuts, bolts, buttons, and the like. You can buy storage systems but you may be put off by the price.
Step 1: Materials
Large number of cleaned cat food cans or other small free containers. Cardboard. Construction adhesive.