Penny Cage for Model Train Weight

As a model railroader I often build train cars in HO scale, and often the plastic cars need extra weight to track well. Some common weights like stick on lead tire weights work well, but I like using pennies. I have tons of them, like everyone else, and they cost, well, pennies! The problem is that even when glued together and to the floor of the model they can break loose and rattle around inside the model and throw it off balance if shifted to the side.

This cage is designed to hold three s