Laura, that is fantastic! I'm impressed... you could have bought that for a couple hundred dollars! Wow!

I am planning on making my own cat tree too - out of real tree limbs! My mom had her oak tree trimmed and she brought me up a few pieces so I could make a cat tree. I have the carpet left over from when our house was carpeted... how much cheaper can I get? I like the sisal idea, so I'll have to hunt down a way to get some free sisal roping! LOL

As for brackets, couldn't you use door hinges? Screw one side to the underside of the one level, then to theoside of the bracket to the back of the ramp?