[Joe Schornak]

We had a similar issue until yesterday. As the ball reached the end of our intake track, it would push the polycord out of its groove. We determined that this was happening because the curvature of the ball was pushing the cord to one side or the other, which caused it to hit the edge of a groove at an angle when the ball reached the inner roller and pull out of place. Judging from your picture, it looks like the middle loop is being significantly pulled to one side, which may be one of the causes of this issue.

Somewhat counterintuitively, loosening the troublesome loop relieved the problem. We ended up completely removing it in the end, since the intake worked just as well with two cords rather than three, but I do not know how this would affect your design.

Also, the process of pulling the ball against an angled rail could be pushing your cord. In my experience, the balls have significant grip against many surfaces, so you could try putting a slicker surface where the ball would contact. We have used teflon tape in similar applications with positive results.

Let us know if you have any further issues, and have a most excellent final build week.