Fix the original model.
Multiple roller models does not connect together, but I have a CR10 so 40cm height is plenty for me.
I've also made a double mount model, since my cat is pretty smart and can reach around a single one.
If you don't have a CR10, then you can just reduce the height of the roller in your slicer.
PLA is not affected by rain, but direct sunlight can bend the model a bit (although it will probably not break the model).
catfence-mount--double.stl | 77.1KB | |
catfence-mount--single.stl | 61.6KB | |
catfence-roller.stl | 61.3KB |