PeterH:
Retroplayer:
If I am understanding him right, the stops have the < and > groove to them to redirect the follower into the other track.Yes, but it's not the ends I'm asking about - it's the crossing points in the middle. When the grooves cross what's to stop the follower from changing direction? At the end of the track there's only one option and the follower has to change direction. But at the intermediate crossing points, there are two options and nothing to prevent the follower from taking either of them.
oh... the follower is long enough that it touches both sides even at the crossing points so it stays on the track it is on. And the tapers on the end of the follower are designed to allow it to flip angle at the ends. The shape of the follower is actually the most important part of the mechanism.