Having decided I'd done enough carpentry for the year, I decided to do one last bit of carpentry after all. These ramps are preparatory to us getting a cat (or more than one cat). It's intended to serve several purposes. First, to give the cats a way to escape from the dog; not because she'd be mean to them, but because she might be unrelenting in her desire to play and be too friendly. Second, to provide a platform (in the middle) where we can set the cat food so the dog can't get to it. And third, to be a sort of cat "jungle gym" like those $200 ones you can get at pet stores, but made for about $30 and in a couple of hours.
At the very top there's a perch which expands slightly on the shelf that's already there and probably big enough for a cat. The perch has some carpet on it, either for comfort, or scratching. Leading up to it are four ramps made of 1x12s (the topmost one is a 1x10) also topped with carpet. The feeding platform doesn't have carpet (that would just make it harder to clean), and has edges on two sides, to prevent the cat dish from being pushed off.
Compared to my last project, this was super-easy, particularly since it didn't need things to be measured precisely, cut perfectly straight, or lined up perfectly. I only had rough measurements to start with, to be sure I had enough materials. The angles aren't consistent, and aren't intended to be -- it's supposed to be for cats to run up and down, so there's a variety of slopes (though I feel sure a cat will have no problem going up any of them).
It was pretty much as simple as taking on-the-fly measurements, cutting the wood to length, sanding the ends, then laying it out on the carpet (on the back) and cutting the carpet to size. Staple the carpet down, then affix brackets and mount. I put the platform up before the piece leading to it, to make sure things would fit, and the same with the perch. (The perch needed a little shim due to the molding up there on the wall, which I installed on the fly on the ladder.) Even the walls for the feeding platform were a simple matter of cutting strips of wood to length, drilling holes down through them, and affixing with long wood screws; the important part there was sanding everything very well.
This is probably as good as, or better than, a $279 cat tree, and was mostly made with scraps of things I already had around. I'm quite pleased with it. I just hope that, when we get cats, they actually use the darned thing!