Cytron RB-Cyt-39: http://www.robotshop.com/cytron-simple-rotary-encoder-kit.html
I have spend the last hour looking on USFIRST for a list of allowed parts, but didn’t find it, and so started just searching for the part used anywhere and didn’t see it. I’m a bit worried about them being legal…
All parts are legal to use on a FRC robot unless the game manual specifically says otherwise.
If you do not know if a particular component is legal to use on a FRC robot, open The Robot section of the manual and go through the rules one at a time. There are three possible outcomes: 1) the rule does not prohibit it; 2) the rule does not apply (ex: bumper rules don’t apply to what motors are legal); or 3) the rule prohibits it. If after going through the entire Robot section of the manual no rules prohibit and/or restrict the component, it’s legal to use.
For this specific sensor, there are no restrictions that would prohibit using this sensor on an FRC robot. However, you should read all relevant rules in the electrical section so you know what you can and can’t wire this sensor to.
Those sensors are well under the dollar limit and we have used similar ones in the past. ::safety::