Hmmm....Well, I don't know of anywhere that has actual plans to go by for you to build one, but are you mainly concerned with the whole thing (like you have absolutely no idea where to start) or are you just stuck on what angle you will have to set the saw to to cut the wood to give you a hexagon?
In any event, if it were me building a basic stand just to hold the tank on and nothing more (just something basic) I'd probably do this...
(1) I'd cut out the exact shape of the tank on a piece of wood which would give you basically a piece of wood that looks like a hexagon. To make it easy, you could probably just rest the tank on the wood and trace it and then cut it from there which would leave you with a piece like
attachemt 1. You'll need 2 of them. One for the top for the tank to sit on and one for the bottom
(2) Next, to block in all the sides and keep a perfect hexagonal shape, you will have to set the saw to I believe it is 60 degrees and cut your pieces from there which will give you pieces like
attachment 2 that you would screw in between the top and bottom. Then you could probably just re-inforce it with some 2x4 on the inside.
Just a thought...Never built one so just tossing out some idea that popped in my head until someone with more knowledge or a diagram chimes in. Good luck!
