I need a laser level, but I don't need one very often so dropping a few hundred on something I might use once in a while was just not going to happen.
That still left me with out a laser level, and the only solution was to make one.
So with nothing more than a few hand tools and some odds and ends from my junk pile I got to work.
For my automatic laser level I decided to use a gimbal and because I wanted to make the most accurate device possible I needed to make it as smooth and precise as possible.
What I needed was a cheap and highly precise bearing assembly already made. That's when I hit on the idea of using the bearing assembly from a HDD.