Motorcycle fuel gauge
 

If you ever owned a bike, you probably thought about doing this at one point :)

Yes, poking a hole in a gas tank is a nerve racking task, do it at your own risk. But it is pretty easy after that, the other end connects to a TEE inserted in the fuel line.

http://opengauge.org/cycle/fuelgauge.JPG

Are you making an old school sight tube, or is this for the laser apparatus you've developed?

- LostCause

Right now it is just an old school sight tube, but having a vent tube can be handy for other gizmos. I really like having it though, it is way better than nothing, I should try and put some marks on it.

I like it!

It fits the criteria of cheap and functional!

Also, anything you can homen-brew instead of running out and buying a "product" gets points in my book.

If I punched a hole in my tank, all the electrons would fall out....