Thread: suggestions on making a tower

Hi I think I may have posted this already but not used to the site and cant find it so.....
I would love to make a tower for our cat. they are too costly for us for now, we have lots of tools and tons of scrap wood here to work with. I would love any ideas on making my own, what kind of matls to use, where to find the round shapes so many seem to have etc! Also it seems the base might have to be really of big to keep it stable with such a big cat climbing on it. I also need to make a scratch post asap as my couch is taking a beating. So far he hasn't been interesting in any scratching things I have. How tall ought a post be for an 19 lb cat??
Any one have cats that like those hammocks? Thanks!!