Cool cat infinite loop with track insert for adding the ball. Instead of printing in place. This is an original design. Not a remix. The 40mm diameter ball has a 2mm flat on the bottom that sits on the printer bed. It makes the ball click a little going around the track, which cats love.

Just add the ball into the track then glue the insert in. Two versions, with and without windows. There are 9 windows around the outside for a cat's 9 lives! Also, cats are happier with a playmate. So, there are 9 windows on the inside for the playmate, too.