How can I float a small ring magnet?
I am creating a fluid level indicator for my automated drink mixer and need either an alternate solution or an item that can float a small ring magnet.
Currently, my idea is to sink a reed switch into a straw, with a ring magnet around the straw. Once the magnet floats down to the reed switch, it lights up the indicator that the alcohol is (almost) gone.
Unfortunately, I cannot find a durable non-toxic way to make the magnet float. I've done several searches and the closest matches I've found are fishing tackle, which I'm not sure would work all that well. I've found manufactured devices, but $30 per bottle is a bit much to spend. I'd like to keep it to under $5 per bottle.