Excellent job, Cheap!
I'm in the process of doing the exact same thing.
My dimensions are:
BOX: 10.5"L x 7"W x 11.25"H (complete...it's freakin' HUGE!)
INJECTOR: .75"
GATE VALVE: 1.5"
FOAM RISER: Undecided height x 6"OD
C-CUP: Undecided height x 6"OD
C-CUP FOAM SPOUT: Undecided height x 2"OD
I'm planning on running this monster on the Dolphin DP-1200. I can always gate it back if it proves to be too much pump. But mine just so happens to match the dimensions of the 240 so closely that I don't think it'll be a problem.
I had originally designed, and cut the part, to have the inner platform for airspace, just like on the original. But, after seeing your design mod, I may well leave out that part in favor of the "injector riser" like you have used. Much easier to assemble, plus it will give me that extra 1" of space in the mixing box!
BIODRAGEN:
You said something about patenting this skimmer. That patent already belongs to someone else (Jason Kim). You'll never (hopefully) see these skimmers for sale from a DIYer. One-offs of a patented design are fine as just that, one-offs for personal use. Anyone caught selling this skimmer would be in a bit of trouble with Jason and his lawyer, I would think. Unless, of course, you managed to wrangle some kind of agreement out of Jason (heheheh, yeah right! He's got one of the best skimmer designs on the market...fat chance!) Just FYI, it's not so much the box and riser that are patented, but the Spray Injection method itself.
Someone else mentioned modding a Beckett into a Spray Injection. It seems lke it would be an easy mod. Just cut the Beckett riser down, put a new cap on it, and tap in your injector and air intake, and away you go. Of course, this would depend on how the internals of the box are set up. If your Beckett has an internal tube that directs the foamy water up into thte riser, I don't think it would work well. The injector must be able to force its water jet deep into the mixing box.
FWIW,
Kev