There's all kinds of cook stuff you can make at home.  The first desktop computer was made in a garage.  People have build boats and cars.  Let's not also forget those people experimenting with crazy chemicals.  One thing you probably shouldn't build is a MACHINE OF DEATH.  More after the break.

What could possibly go wrong when you build a machine designed to sever heads?  Fortunately the man involved is still alive. I guess even idiots have limits as to what they'll stick in their homemade guillotines.  Check it out: