Quoted from TheOnlyest:They are tiny, you can put them on the bottom or the side with super thin 2-sided tape. They are magnetic so the ball just needs to pass by it. They dont have to be mounted in the same spot as the gate, just close where there's room to attach it. If you attach them to the side, just dont put them where a metal ramp guard is in front of it. If I was in your situation, this is the only remedy I would be looking at... But i'd wanna know about the activation range of the MRS, because the ramp openings are pretty wide.
Yes, and I wasn't sure about how fast a ball could go by and be detected. The only reed switch I ever used was in the toilet bowl of a creature to get more revolutions out of the ball without slowing it down with a switch... But that ball was nice and slow.