I just made one. Here is a pic of their first day in a C&C cage. When I adopted them, the both them were in a My First Home cage, and they were starting to fight and were not happy (though they are mother and baby). I promptly built them (after a deperate search on the internet for larger that pet store cages) a 4 x2 two story C and C cage. Cost me less than 100 including the table from Staples, zip ties, fake grass and wood glue for the ramp, and a second home for them to use.
Here is another shot!
Since I switched their cage, they immediately began to popple around and jump up and down (literally!). They are so vocal, constantly, which I hadnt heard the week I had them... before the C&C cage. They are much much happier. They drive my dog nuts because they are so active, all day and all night.