These are some neat little DIY tools you can do, with stuff that you probably use once in awhile.
These tricks will probably serve you in a daily basis, and they are made possible by the youtube channel called Mr.
Gear. Just by using a 9V battery, a couple of bells, pins, wires and bolts, you will have useful tools that will come to your service everyday. In this video you will learn to build a sort of energy creator, that you can use as a lighter, a hole saw and a simple trip alarm. Anyway check the video out for more details on these little tools, that will save you some money if built.