If you go into my photo gallery (the litter camera on the top of my post)
You notice that I put up extensive pictures showing how to use grids for your base. I've even entered close-ups along with text to explain the pictures. Cable (or zip) ties
are not optional if you want a kid proof/pet proof/vacuum proof cage -- but they
are cheap cheap cheap (in honor of Easter time) and they ridiculously easy to use.
I've shown how to use the ties to attach the grids for a base.
In my gallery are photos of my cage, in progress, and then completed which is so sturdy that
I've laid down in the cage with the boys many times and I weigh more than 200Lbs! I've moved it from room to room about 10 times and the only problems are when a connector pops off occasionally, when I vaccum, but since they are zip tied it's no worries and I slide it back on. I simply lift off my upper level (which is a complete cage of it's own) and then lay the cage on it's side to slide it from room to room.
It's about the size of a double bed mattress. Recently hubby even added wheels but attaching the legs from two wheeled carts, kind of like this (old ones from Kmart that were super cheap and we were tossing) to the sides and I can roll it to clean under it. He zip tied the legs at the cross bars and put one of each side of the shelves on each corner of the cage. I need to add pictures of it for others... 