It's a pretty simple design, actually. A piece of 11.25" wide board, cut to a length of approximately 13" inches, with a few chunks of shaped molding glued to its front, is the extent of it. I also took another piece of wood (a 1" by 1" square), then glued and nailed it to the back, to provide a small rise to the rack surface.
Finally, I took a couple of eyehooks and screwed them into the underside of the holder to help hold and organize the USB cables running to the Korg devices. They're ugly, but functional, and keep the cables nicely organized. If I added a third Korg device to my "rack" I suspect I'd be even more thankful for the eyehooks keeping the wires in control.
I didn't bother sanding down the edges on the bottom of the rack to make it flush with whatever surface its sitting on, which would have make it even more stable, but I added little adhesive feet to give it some cushion and to keep it from scratching things beneath it.
As you can probably see, I applied a couple of coats of stain to finish it. It's a little darker than the can seemed to suggest it would be, but it looks nice enough.
If you plan to build something like this yourself, I have a couple of suggestions for you. First, make sure that the main board you use is nice and sturdy. When I was originally planning the NanoRack, I was thinking I'd use a small piece of press board, similar to what you get with a clipboard. While the piece would have been much lighter, I'm not sure I'd feel very comfortable with really pounding on the drum pads of the nanoPad if there was just a skinny piece of particle board behind it. The board I used was about 3/4 of an inch wide and feels rock solid.
Second, try to use or borrow a good saw. The one I used to cut the molding for the front had too course of a bite and really tore my pieces of wood apart. Closer inspection shows big, ugly gaps where the wood splintered and broke. So, either use a better saw, or buy plenty of extra molding in case you have the same luck I did.
Third, if I were building another one for myself, I think I'd want a higher riser, so consider the angle you want for your devices while you're in the hardware store purchasing wood. The 1" x 1" piece I used to give my holder its angle is fine, but I think I'd be even happier with a 2" piece. I have more of the 1" x 1" board, so I suppose I could glue it to the bottom of the first piece, but more pieces means less long-term strength. It might work, but I don't know how long it would last.
I'm not what you would call "handy," so someone with a bit of wookworking skill and access to quality tools, should be able to make something a lot nicer without a whole lot more effort. Still, for a simple hunk of wood, its surprisingly nice, turing "portable" control surfaces into something a little more sturdy and useful "in the studio." I'm imagining all sorts of possible improvements, such as drilling a hole into the piece of wood I'm using as a riser to allow you to run your USB cables out the back of it. Or, even better, building a mini USB hub into the rack, making it possible to run just one cable from your Korg Rack to your computer.
I was concerned about the strength of the molding on the front of the piece and thought about using some nails, in addition to the wood glue, to hold them in place. However, my fear of splitting the wood by hammering into it with nails eventually made me decide against it. It should be fine, but might also be an area where you could improve on my design, if you try this yourself.
As you can see, I designed it to hold all three of the Korg nano series devices, even though I only have two at the moment. Use a smaller piece of wood or increase the size of the gaps between the nano controllers, if you want to build something like this for two devices. Or, build it for three, and find something else to put in your controller rack, like I did. The Casio VL-Tone is nearly a perfect fit.
What does this have to do with Reason? Not much, but I was pretty pleased with my weekend project, and thought I'd share.