[iambujo]

Squirrel - that's the part I have had good luck with. I got it from sparkfun.

Al - We are looking to use this on a flywheel (hint hint). So I hope it won't take as much abuse as a drive-train wheel, but it will be spinning faster so loose parts would be even more dangerous. If we can't be sure we can attach safely we will certainly abandon the idea for this application.

As for a reed switch. I have never used one. They contact due to magnetic field detection, but it is a mechanical motion right? So I was concerned about lifespan (how many times are they design to switch) and switching speed. I am certainly curious if someone thinks they can work for this as well.

I really like the looks of that Honeywell sensor mentioned above. That's a pretty steep price compared to the hall latch (under $1), but if it provides a simple and stable solution it's certainly worth trying out.

I love FRC build season - it really gets the brain going non stop!