Our preference is to protect the Arwen plastic, but we know that some folks just prefer to have the ball always run down the habitrail. So here's our answer. We've made a simple deflector that always feeds the ball into the habitrail. Our deflector is made from one of our favorite materials - acrylic - which is perfect for this application. Once installed, it is pretty much invisible.
Easily and quickly removed and installed. Mounts with existing hardware. Do not overtighten.
Here's what it looks like installed.