At the end of summer when my kids were in need of school supplies, we ended up passing through the local dollar store to find a few things. Right next to the pencil boxes and binders were plastic food containers for the kids to bring lunches and snacks to school in. As soon as I saw them, I realized they would make fantastic project enclosures! Here is the dollar sandwich container housing a Spark Core and a Relay Shield for my Compressed Air Rocket Launcher (I didn’t have a 9V battery clip on me when I put this together so the pink bubble wrap is there to keep the battery from knocking around):
The even smaller “snack” size boxes came in packs of three for $1. Each one is a perfect (well, maybe a little tight) enclosure for an Arduino Uno with a a Shield and a 9V battery:
The one thing you do need to look out for is that sometimes the plastic can crack when you are drilling holes, so take your time, go slow. And if you end up breaking one, it was only a buck!
Also, I went back just the other week, and the “back-to-school” stock has been pulled and replaced with Halloween items. I couldn’t find these containers in my local dollar stores any more. There were others, but I didn’t like them as well. However with some searching, I was able to find some online on dollartree.com